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Title:
ENERGY DISSIPATION DEVICE FOR STRUCTURES AND METHOD FOR LIMITING/BLOCKING THE DEFORMATION OF AN ENERGY DISSIPATION DEVICE FOR STRUCTURES
Document Type and Number:
WIPO Patent Application WO/2021/053594
Kind Code:
A1
Abstract:
An energy dissipation device for structures, comprises: a perimeter wall delimiting at least one internal housing, wherein the perimeter wall is configured to be connected to structural elements, e.g. of a building; at least two shear panels (3) connected to the perimeter wall; at least one blocking element (4) arranged between the two shear panels (3) and in contact with the two shear panels (3). The perimeter wall and the shear panels (3) are deformable and/or movable with respect to the blocking element (4) when the device is subjected to loads, in order to dissipate energy. At least one blocking portion (14) of the blocking element (4) is configured to abut against at least one abutment portion of the perimeter wall when the perimeter wall reaches a limit deformation configuration.

Inventors:
CALIO' IVO DOMENICO (IT)
IZZUDDIN BASSAM AFIF (GB)
SCURRIA MAURO (IT)
Application Number:
PCT/IB2020/058703
Publication Date:
March 25, 2021
Filing Date:
September 18, 2020
Export Citation:
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Assignee:
SICILFERRO TORRENOVESE S R L (IT)
International Classes:
E04H9/02; E04B1/98
Foreign References:
US20110107699A12011-05-12
KR101578198B12015-12-29
KR101321416B12013-10-23
KR101761338B12017-07-26
Attorney, Agent or Firm:
BRASCA, Marco (IT)
Download PDF:
Claims:
CLAIMS

1. Energy dissipation device for structures, comprising: a perimeter wall delimiting at least one internal housing, wherein the perimeter wall is configured to be connected to structural elements of a structure; wherein the perimeter wall is configured for being deformed when the structural elements and the device are subjected to loads which exceed a predefined limit; at least two shear panels (3) connected to the perimeter wall and substantially transverse with respect to said perimeter wall; at least one blocking element (4) arranged between the two shear panels (3) and in contact with said two shear panels (3); wherein the perimeter wall and the shear panels (3) are deformable and/or movable with respect to the blocking element (4) when the device is subjected to loads, in order to dissipate energy; wherein at least one blocking portion (14) of the blocking element (4) is configured to abut against at least one abutment portion (15) of the perimeter wall when the perimeter wall reaches a limit deformation configuration.

2. Device according to claim 1 , wherein only the perimeter wall is configured to be connected to the structural elements of the structure.

3. Device according to claim 1 or 2, wherein different zones of the perimeter wall are configured to be connected to different structural elements.

4. Device according to claim 1 or 2 or 3, wherein, in a configuration different from the limit deformation configuration, the blocking element (4) is free to move with respect to the perimeter wall and said at least one blocking portion (14) lies spaced from said at least one abutment portion (15). 5. Device according to one of the claims 1 to 4, comprising at least one layer of dissipative material (5) interposed between said at least one blocking portion (14) and said at least one abutment portion (15).

6. Device according to one of the preceding claims 1 to 5, wherein the blocking element (4) is a blocking plate, wherein said at least one blocking portion (14) is placed on a peripheral edge of the blocking plate (4) and wherein said at least one abutment portion (15) is defined by an inner surface of the perimeter wall.

7. Device according to claim 6, wherein the shear panels (3) have a square or rectangular shape, wherein the perimeter wall has four sides and the blocking plate (4) has a polygonal shape, optionally octagonal shape.

8. Device according to claim 6 or 7, wherein the blocking plate (4) has curved sides.

9. Device according to claim 7 or 8, wherein, in a rest configuration, only some points, optionally edges, optionally rounded, of the blocking plate (4) can touch the perimeter wall while, in the limit deformation configuration, sides of the blocking plate (4) lie against the perimeter wall; wherein said sides define said at least one blocking portion (14).

10. Device according to one of the claims 6 to 9, wherein the blocking plate (4) has a perimeter portion with reduced thickness with respect to a central portion thereof.

11. Device according to one of the claims 6 to 10, wherein the blocking plate (4) is hinged to the shear panels (3) at respective centers (C).

12. Device according to one of the preceding claims 1 to 11, wherein the shear panels (3) are welded or bolted to the perimeter wall.

13. Device according to one of the preceding claims 1 to 12, wherein the perimeter wall comprises a plurality of side panels (2) connected to each other, optionally by welding or through a comb coupling or through a bracket coupling or welded connection with section reduction or connection by means of slotted joints.

14. Device according to claim 13, wherein contiguous side panels (2) rotate with respect to each other when the perimeter wall is deformed.

15. Method for blocking or limiting the deformation of an energy dissipation device for structures, wherein the device comprises: a perimeter wall delimiting at least one internal housing, wherein the perimeter wall is configured to be connected to structural elements of a structure; wherein the perimeter wall is configured for being deformed when the structural elements and the device are subjected to loads which exceed a predefined limit; at least two shear panels (3) connected to the perimeter wall and substantially transverse with respect to said perimeter wall; wherein the perimeter wall and the shear panels (3) are deformable when the device is subjected to loads, in order to dissipate energy; wherein the method comprises: placing at least one blocking element (4) between the two shear panels (3) and in contact with said two shear panels (3); wherein said blocking element (4) is configured for limiting the deformation of the energy dissipation device once a limit deformation configuration or blocked configuration has been reached.

Description:
“Energy dissipation device for structures and method for limiting/blocking the deformation of an energy dissipation device for structures”

DESCRIPTION

Field of the invention

The object of the present invention is an energy dissipation device for structures, for example of buildings and/or of infrastructures, such as bridges, viaducts, etc., and a method for limiting/blocking the deformation of an energy dissipation device for said structures. In particular, but not exclusively, the present invention is situated in the scope of devices configured for dissipating the energy of seismic events, controlling the forces generated by earthquakes, reducing the drift/movement of the parts of the structures, in particular of multilevel structures, and therefore preventing considerable structural damage and/or the collapse of the structures themselves.

State of the art

In the scope of seismic energy dissipation devices, structural joints are known which shear and, due to their elastoplastic properties, allow dissipating the energy. Joints which shear (termed “shear links”) are widely used for building structures in regions with high seismic activity.

For example, structures are known that are made with eccentric rod reinforcement systems (Eccentrically braced frames ‘EBFs’) which comprise joints which shear in vertical or horizontal configuration. The article “Seismic performance of high- strength steel fabricated eccentrically braced frame with vertical shear link” (Journal of Constructional Steel Research, Volume 137, October 2017, Pages 262-285) describes solutions of such kind.

The documents KR101578198B1 and KR101321416B1 illustrate dissipation devices which comprise a plate shaped as an X and comprised between other plates so as to limit the buckling outside the plane. The document KR101321224B1 illustrates a device with plates which provides for the execution of holes in the plates. The document KR101761338B1 illustrates a variant of the preceding device comprising a plurality of removable plates. Also known is the document US20060150538A1 which illustrates a load limiter configured for being placed in an additional reinforcement system of the above- described type. The load limiter is connected to the diagonal arms of the reinforcement system and is able to limit the lateral loads induced in the structure during a dynamic event, e.g. seismic event, through plastic deformations.

Also known is the document US 2011/0107699 which illustrates a metallic joint provided with a damper element that is mounted between two structures. A frame (first structure) is constrained to a foundation (second structure) through such joint. The joint is connected to the frame (first structure) through bolts and is connected to the foundation (second structure) through an anchorage screw. The joint comprises a quadrangular frame, damping plates welded to the quadrangular frame, a cylindrical element placed between the damping plates and connected to such damping plates through welds. The quadrangular frame is connected to the first structure and the cylindrical element is connected to the second structure through the anchorage screw. In case of earthquake, the quadrangular frame moves in one direction while the cylindrical element moves in the opposite direction and the damping plates are deformed.

Object of the invention The Applicant has observed that the above-described devices of known type have several drawbacks.

The Applicant has in fact verified that the joints which shear of the above-described prior art, such as KR101578198B1, KR101321416B1, KR101321224B1 and KR101761338B1 , allow dissipating the energy and also perform the function of load limiters but do not allow limiting the size of the deformations once they enter into the plastic field.

The Applicant has also verified that the solution described in US20060150538A1 does not ensure the control of the drift between levels/floors of multilevel buildings (inter-story drift: later displacement of one level with respect to an adjacent upper or lower level) and this can involve the collapse in case of earthquake.

The Applicant has also observed that the solution described in US 2011/0107699 is capable of working in only one direction, i.e. along the anchorage screw, and in addition the elements which connect the first and the second structure are the same that provide the damping effect. In fact, the anchorage screw is joined to the cylindrical element which is joined to the plates which, in turn, are joined to the quadrangular frame. It follows that the deformation/breakage of the damping elements/plates and/or of the cylindrical element would compromise the connection between the first and the second structure.

In such context, the Applicant has therefore set the objective of proposing a device/joint that shears, capable of overcoming the abovementioned drawbacks. The Applicant has first of all set the objective of proposing a joint/device that shears which is capable of dissipating energy but also of limiting the deformations thereof In particular, the Applicant has set the objective of proposing a joint/device which, if subjected to medium-low seismic excitation levels, behaves like a known joint, capable of dissipating energy and limiting the transmission of the forces, and which, in the presence of higher excitation levels, is capable of limiting/blocking the deformation thereof. The Applicant has therefore set the objective of proposing a joint/device capable, in the presence of the abovementioned higher excitation levels, of limiting the movement/drift between levels/floors of multilevel structures (inter-story drift), possibly of redistributing the energy dissipation to other levels of the structure which are still within the provided deformation limits thereof, and therefore protecting the structural integrity of the structure itself.

Summary of the invention

The Applicant has found that such further objectives and objects can be obtained by an energy dissipation device for structures, e.g. of buildings and/or of infrastructures, and by a method for blocking or limiting the deformation of an energy dissipation device for said structures in accordance with the present invention, of the type claimed in the enclosed claims and/or described in the following aspects.

In particular, the Applicant has found that such further objectives and objects can be obtained by implementing a blocking system in a joint/device which shears and is capable of dissipating energy, so as to limit the deformation of the joint itself.

In accordance with one aspect, the present invention relates to an energy dissipation device for structures, comprising: a perimeter wall delimiting at least one internal housing, wherein the perimeter wall is configured to be connected to structural elements of a structure; at least two shear panels connected to the perimeter wall and substantially transverse with respect to said perimeter wall; wherein the perimeter wall and the shear panels are deformable, when the device is subjected to loads, in order to dissipate energy; a blocking element placed between the shear panels and configured for limiting the deformation of the dissipation device once a limit deformation configuration, also termed blocked configuration, has been reached.

In one aspect, the blocking element is arranged between the two shear panels and in contact with said two shear panels and at least one blocking portion of the blocking element is configured to abut against at least one abutment portion of the perimeter wall when the perimeter wall reaches the limit deformation configuration or blocked configuration.

In accordance with one aspect, the present invention relates to an energy dissipation device for structures, comprising: a perimeter wall delimiting at least one internal housing, wherein the perimeter wall is configured to be connected to structural elements of a structure; at least two shear panels connected to the perimeter wall and substantially transverse with respect to said perimeter wall; at least one blocking element arranged between the two shear panels and in contact with said two shear panels; wherein the perimeter wall and the shear panels are deformable and/or movable with respect to the blocking element when the device is subjected to loads, in order to dissipate energy; wherein at least one blocking portion of the blocking element is configured to abut against at least one abutment portion of the perimeter wall and/or of at least one of the shear panels when the perimeter wall reaches a limit deformation configuration or blocked configuration.

In accordance with one aspect, the present invention also relates to a method for blocking or limiting the deformation of an energy dissipation device for structures, wherein the device comprises: a perimeter wall delimiting at least one internal housing, wherein the perimeter wall is configured to be connected to structural elements of a structure; at least two shear panels connected to the perimeter wall and substantially transverse with respect to said perimeter wall; wherein the perimeter wall and the shear panels are deformable when the device is subjected to loads, in order to dissipate energy.

The method comprising: placing at least one blocking element between the two shear panels and in contact with said two shear panels; wherein said blocking element is configured for limiting the deformation of the dissipation device once a limit deformation configuration or blocked configuration has been reached.

The abovementioned perimeter wall is configured for being deformed when the structural elements and the device are subjected to loads which exceed a predefined limit.

The Applicant has verified that the device according to the invention first of all allows limiting the deformation of the joint, while ensuring the energy dissipation.

The Applicant has in fact verified that the blocking element according to the invention does not compromise the dissipation function of the joint when the deformations are lower than the limit, and it comes into play - blocking such deformations - only upon reaching said limit. The Applicant has also verified that, in the field of deformations in which the blocking element does not perform its own blocking function, this can contribute to the energy dissipation by sliding against the shear panels.

The Applicant has also verified that the blocking element contributes to preventing buckling phenomena without having to introduce further panels into the joint/device that are dedicated for such purpose.

The Applicant has also verified that the device according to the invention can be inserted after construction in pre-existing structures (retrofitting), also in order to replace existing joints.

Further aspects of the invention are described hereinbelow. In one aspect, only the perimeter wall is configured to be connected to the structural elements. In other words, only the perimeter wall is directly attached to the structural elements, the shear panels and the blocking element are not directly joined to such structural elements. Such shear panels and the blocking element are connected to the and/or retained by the perimeter wall.

The device is configured for being joined to the structural elements only through the perimeter wall thereof.

In one aspect, the perimeter wall is attached to different structural elements.

In one aspect, different zones of the perimeter wall are configured to be connected to the structural elements.

In one aspect, different zones of the perimeter wall are configured to be connected to different structural elements.

In one aspect, in a configuration different from the limit deformation configuration, the blocking element is free to move with respect to the perimeter wall.

In one aspect, in a rest/undeformed configuration or in a configuration different from the limit deformation configuration, said at least one blocking portion lies spaced from said at least one abutment.

In one aspect, in the limit deformation configuration, the blocking element is substantially fixed with respect to the perimeter wall.

In one aspect, in a configuration different from the limit deformation configuration or blocking configuration, the blocking element does not contribute to the resistance of the device.

In one aspect, in the limit deformation configuration, the blocking element is substantially in contrast with respect to the perimeter wall.

In one aspect, at least one layer of dissipative material is interposed between said at least one blocking portion and said at least one abutment portion.

In one aspect, a dissipative material is interposed between the blocking element and the perimeter wall.

In one aspect, the dissipative material is rubber or metal.

Such layer of dissipative material is deformed during the deformation of the perimeter wall and of the shear panels, so as to maximize the dissipation and allow a gradual transition to the blocked configuration.

In one aspect, the perimeter wall and/or the shear panels and/or the blocking element are made of metal, optionally of steel.

In one aspect, the perimeter wall and/or the shear panels and/or the blocking element are made of materials that are different from each other. In one aspect, the blocking element is a blocking plate.

In one aspect, the blocking plate is clamped between the two shear panels. This has as benefit that of increasing the energy dissipation during the deformation and of increasing the performances of the shear panels with buckling attained (post- buckling range).

In one aspect, the blocking plate is not joined to the perimeter wall. The blocking plate works under diagonal compression at specific shear deformation levels of the shear panels and this allows controlling the drift/movement (drift control).

In one aspect, during the deformation the blocking plate slides against the shear panels.

In one aspect, said at least one blocking portion is placed on a peripheral edge of the blocking plate.

In one aspect, said at least one abutment portion is defined by an inner surface of the perimeter wall, i.e. by a surface delimiting said internal housing.

In one aspect, the blocking plate lies parallel and side-by-side the shear panels.

In one aspect, the blocking plate has a shape different from a shape of the shear panels.

In one aspect, at least in an undeformed configuration, the shear panels have a square or rectangular shape.

In one aspect, the perimeter wall has four sides.

In one aspect, at least in an undeformed configuration, the perimeter wall has a square or rectangular shape.

In one aspect, the blocking plate has a polygonal shape.

In one aspect, the blocking plate has a shape with a number of sides greater than four.

In one aspect, the shape of the blocking plate is octagonal.

In one aspect, the shape of the blocking plate has rounded edges.

In one aspect, the blocking plate comprises a central portion and at least one auxiliary plate arranged on at least one of the opposite faces of the central portion; wherein sides of the auxiliary plate define auxiliary blocking portions.

In one aspect, the sides of the auxiliary plate are arranged on a more internal perimeter with respect to the sides of the central portion. In one aspect, the sides of the auxiliary plate have different tilts with respect to the sides of the central portion.

In one aspect, the sides of the auxiliary plate are in a number equal to or different from the sides of the central portion.

In one aspect, in a rest configuration, only some points, optionally edges, of the blocking plate touch or can touch the perimeter wall.

In one aspect, the shape of the blocking plate has curved sides.

In one aspect, in the limit deformation configuration or blocked configuration, sides of the blocking plate lie against the perimeter wall, wherein, optionally, said sides define said at least one blocking portion.

In one aspect, in the limit deformation configuration or blocked configuration, contiguous sides of the blocking plate lie against contiguous sides of the perimeter wall.

In one aspect, in the limit deformation configuration or blocked configuration, contiguous side panels of the perimeter wall delimit an angle equal to an angle between contiguous sides of the blocking plate.

In one aspect, in the limit deformation configuration or blocked configuration, the perimeter wall takes on a bent or rhombus form.

In one aspect, the device comprises a plurality of blocking plates interposed between a plurality of shear panels.

In one aspect, the device comprises a plurality of blocking plates, each interposed between a pair of shear panels.

In one aspect, the blocking plate has a perimeter portion with reduced thickness with respect to a central portion thereof.

In one aspect, the blocking plate is thinned towards a perimeter portion thereof. This allows maximizing the dissipation and leading to a gradual passage to the blocked configuration.

In one aspect, the blocking plate is hinged to the shear panels. This allows improving the performances with buckling attained (post-buckling range).

In one aspect, the blocking plate is hinged to at least one of the adjacent shear panels.

In one aspect, the blocking plate is hinged to the shear panel(s) at respective centers. In one aspect, the blocking plate is free to rotate with respect to the shear panel(s). In one aspect, the shear panels are welded to the perimeter wall.

In one aspect, the shear panels are bolted to the perimeter wall. In this manner, it is possible to remove the shear panels deformed after a seismic event and replace them.

In one aspect, the perimeter wall comprises a plurality of side panels connected to each other.

In one aspect, the perimeter wall comprises four side panels connected to each other.

In one aspect, contiguous side panels rotate with respect to each other when the perimeter wall is deformed.

In one aspect, the side panels are connected to each other by welding.

In one aspect, the side panels are connected to each other through fitting.

In one aspect, the side panels are connected to each other through a comb coupling (interlacing comb) or through a bracket coupling (bracketing arrangement).

In one aspect, some of the side panels are provided with folded end portions to define a kind of bracket form.

In one aspect, contiguous edges of the side panels are provided with a series of projections/teeth which form a kind of comb shape.

In these cases, the angle formed by the projections/teeth of the comb or by the folded end portions is a function of the geometry of the blocking plate, i.e. of the desired limit deformation level. This serves to prevent the side panels from being separated from the shear panels under the diagonal compression applied through the blocking plate.

In one aspect, the side panels are connected to each other by welding with section reduction of the panels for the purpose of concentrating the plastic deformation close to the corners.

In one aspect, the side panels are connected by means of grooves (slottings).

In one aspect, each of the side panels is defined by a T or L shaped section.

In one aspect, when the side panels are assembled together, each of the T or L shaped sections has a peripheral wall and a wall projecting towards the interior of the device; wherein the abutment portion is defined by an internal edge of said wall projecting towards the interior of the device. In one aspect, the shear panels are joined to said wall projecting towards the interior of the device.

In one aspect, said at least one internal housing is delimited by the internal edges of said wall projecting towards the interior of the device.

In one aspect, the side panels are T shaped sections, the shear panels are two, the internal housing is one and houses a blocking plate.

In one aspect, ends of adjacent T shaped sections are connected to each other to define a frame, wherein the internal edges of the walls projecting towards the interior of the device delimit a single housing, wherein a single blocking plate is housed in said single housing and is closed between two shear panels.

In one aspect, the side panels are L shaped sections, the shear panels are three, the internal housings are two and each house a blocking plate.

In one aspect, ends of first adjacent L shaped sections are connected to each other to define a first frame, ends of second adjacent L shaped sections are connected to each other to define a second frame.

In one aspect, the first and the second frame are joined together and an intermediate shear panel is interposed between the two frames to delimit a first and a second housing.

In one aspect, two lateral shear panels are placed on opposite sides of the assembly formed by the first frame, by the second frame and by the intermediate shear panel. In one aspect, a first blocking plate is housed in the first housing and is closed between one of the lateral shear panels and the intermediate shear panel.

In one aspect, a second blocking plate is housed in the second housing and is also closed by the lateral shear panels and the intermediate shear panel.

In accordance with one aspect, the present invention also relates to a structure, e.g. of a building or of an infrastructure, such as a bridge or a viaduct, comprising at least one energy dissipation device for structures, optionally a plurality of energy dissipation devices, according to at least one of the preceding aspects.

In one aspect, the structure comprises a plurality of beams and the energy dissipation device or each energy dissipation device is operatively interposed between two or more beams. In one aspect, the structure comprises a plurality of beams and the energy dissipation device or each energy dissipation device constitutes a node of said structure.

In one aspect, the structure comprises a plurality of walls and the energy dissipation device or each energy dissipation device is operatively interposed between two adjacent walls.

In one aspect, the structure comprises a system with walls or rocking separators (rocking wall systems) and the energy dissipation device or each energy dissipation device is operatively associated with said walls In one aspect, the structure comprises two or more energy dissipation devices that are directly connected to each other.

In one aspect, the structure comprises two or more energy dissipation devices placed in series. In this manner, it is possible to increase the overall dissipation of energy and/or better control the required drift considering different limit deformations for each device.

In one aspect, the energy dissipation device is connected to other structural elements of the structure through bolts or welding.

In one aspect, the structure is of multilevel or multi-floor type.

In one aspect, the structure comprises a plurality of sub-structures arranged on each other.

In one aspect, each sub-structure comprises a frame and diagonal beams connected to vertices of the frame (Braced frame (EBF)).

In one aspect, at least one energy dissipation device according to at least one of the preceding aspects joins the ends of diagonal beams to each other. In one aspect, each sub-structure comprises four diagonal beams, wherein each diagonal beam has one end connected to the frame and an opposite end connected to said at least one energy dissipation device. This type of structure allows distributing the forces along predefined paths in the structure itself and controlling the movement/drift between levels/floors of multilevel structures (inter-story drift). Further characteristics and advantages will be clearer from the detailed description of preferred but not exclusive embodiments of an energy dissipation device for structures in accordance with the present invention. Brief description of the drawings

Such description will be set forth hereinbelow with reference to the enclosed drawings, provided only as a non-limiting example, in which:

- figure 1 shows in exploded view an energy dissipation device for structures according to the present invention;

- figure 2 shows in perspective view the device of figure 1 assembled, in which one part is illustrated with dashed line in order to better illustrate another part;

- figure 3 is a front view of the device of figure 2;

- figure 4 shows in exploded view a different embodiment of the device of the preceding figures;

- figure 5 illustrates in exploded view a variant of the device of figure 1 ;

- figures 6, 6a, 6b and 7 to 9 illustrate respective variants of an element of the device according to the present invention;

- figure 10 shows in perspective view a variant of the device of figure 1, in which one part is illustrated with dashed line in order to better illustrate another part;

- figure 11 is a front view of the device of figure 10;

- figure 12 shows in perspective view a further variant of the device of figure 1 , in which one part is illustrated with dashed line in order to better illustrate another part;

- figure 13 is a front view of the device of figure 12;

- figure 14 shows in perspective view the device of figure 12 in a deformed configuration;

- figure 15 shows the device of figure 13 in the deformed configuration;

- figure 16 shows, in perspective view and in exploded view, a further variant of the device of figure 1 ;

- figure 17 shows the device of figure 16, assembled;

- figure 18 shows, in perspective view and in exploded view, a further variant of the device of figure 1 ;

- figure 19 shows the device of figure 18, assembled;

- figure 20 illustrates a frame and diagonal beams comprising the device according to the preceding figures in the embodiment of figures 10 and 11. - figure 21 is an enlarged perspective view of a portion of the frame and diagonal beams of figure 20;

- figure 22 illustrates a multilevel structure comprising a plurality of frames and diagonal beams like that of figure 20; - figure 23 is an enlarged front view of the portion of figure 21 according to an embodiment variant;

- figure 24 illustrates a structural variant of the portion of figures 21 and 23;

- figure 25 is an exploded view of a further embodiment of the energy dissipation device for structures according to the present invention; - figure 26 is a side view of the device in exploded view of figure 25;

- figure 27 is a side view of the assembled device pursuant to figures 25 and 26;

- figure 28 is a front view of the assembled device of figure 27;

- figure 29 is a view in exploded view of a variant of the further embodiment of figure 25;

- figure 30 is a side view of the device in exploded view of figure 29;

- figure 31 is a side view of the assembled device pursuant to figures 30 and 31;

- figure 32 is a front view of the assembled device of figure 31 ; - figures 33 and 34 illustrate portions of the device of figure 32 according to respective further variants.

Detailed description of preferred embodiments of the invention With reference to the enclosed figures, reference number 1 overall indicates an energy dissipation device for structures, e.g. of buildings or infrastructures, according to the present invention.

The device 1 is configured for being plastically deformed up to a certain limit when subjected to typical loads of a seismic event and to block the deformation at a pre- established limit through a blocking element. The device 1 comprises a perimeter wall formed by four side panels 2 connected to each other at opposite edges, which delimits an internal housing. In the embodiment of figures 1 , 2 and 3, the side panels 2 are welded to each other. As illustrated below in the present description, the perimeter wall is configured to be connected to structural elements, e.g. of a building. The device 1 is joined to the structural elements only through the perimeter wall, as can be observed in all the embodiments illustrated in the enclosed drawings. In an undeformed configuration of the device 1, i.e. when said device 1 is not subjected to loads generated by a seismic event, the perimeter wall has a square structure, as is more visible in figure 3, or rectangular structure.

In the internal housing, two shear panels 3 are placed together with a blocking element defined by a blocking plate 4. The two shear panels 3 have perimeter edges thereof joined by welding to the perimeter wall. In an embodiment variant better described hereinbelow, the shear panels 3 are bolted to the perimeter wall in order to be able to remove them and replace them if they have been deformed by a seismic event.

In the abovementioned undeformed configuration of the device 1 , the two shear panels 3 lie in respective planes that are parallel to each other, they are square shaped and arranged perpendicular to the side panels 2. Each of the sides of the shear panels 2 lies completely against one of the side panels 3.

The blocking plate 4 is arranged between the two shear panels 3 and in contact with said two shear panels 3. The blocking plate 4, at least in the abovementioned undeformed configuration of the device 1 , is parallel to the two shear panels 3 and is clamped between the two shear panels 3. The blocking plate 4 is not joined to the perimeter wall, nor to the two shear panels 3 but rather is simply abutted against portions of the perimeter wall and against the two shear panels 3. The blocking plate 4 is operatively coupled to the perimeter wall and to the shear panels 3 and is configured for limiting the deformation of the dissipation device 1 once a limit deformation configuration or blocked configuration has been reached.

The blocking plate 4, the perimeter wall and the shear panels 3 are for example made of steel, but in variants not illustrated in detail they could be made of materials that are even different from each other.

In the embodiment illustrated in figures 1, 2 and 3, the blocking plate 4 has an octagonal shape, like that of figure 6. Pairs of adjacent sides of the blocking plate 4 form greater angles “b”, e.g. close to 180° but smaller than 180° while sides of two different pairs form a smaller angle, e.g. about 100°, which we will define blocking angle “a” (see figure 3). Adjacent sides are joined at edges which can be rounded. As is visible in figure 3, the dimensions of the blocking plate 4 and of the perimeter wall are such that, in said undeformed configuration, only some of the edges touch the perimeter wall. In particular, only the edges with greater angles “b” touch the side panels 2. The embodiment of figure 4 differs from that of figures 1 , 2 and 3 since it comprises three shear panels 3 and two blocking plates 4, each like that already described and each interposed between two of three shear panels 3.

Figures 6a and 6b illustrate variants of the blocking plate of figure 6. In such variants, the blocking plate 4 has concave curved sides (figure 6a) or convex curved sides (figure 6b) or both, in order to ensure an optimal blocking if the perimeter walls take on a curved deformed configuration.

Figures 7, 8 and 9 illustrate respective variants of the blocking plate of figure 6. In the variants of figures 8 and 9, the blocking plate 4 has a perimeter portion with reduced thickness with respect to a central portion thereof In the variant of figure 7, the blocking plate 4 has a central portion having a shape similar to that of figure 6 and, on both opposite faces, auxiliary plates 18 having octagonal shapes. Such auxiliary plates 18 can also be integrally made with the central portion. The auxiliary plates 18 have shorter sides than the sides of the central portion and arranged on a more internal perimeter than the sides of the central portion so as to form steps with said sides of the central portion.

In other embodiments, the blocking plate can have still other shapes.

In one variant of the invention, the blocking plate 4 is hinged to one or to both adjacent shear panels 3 at respective centers “C” (figure 3) and is free to rotate with respect to the shear panel(s) 3 and this allows preventing the buckling (post- buckling range).

Figure 5 illustrates a variant of the device of figure 1 which also comprises four elements/layers 5 of dissipative material (of which only three are visible), e.g. made of rubber or metal, which fill respective volumes delimited between the blocking plate 4 and the perimeter wall. In the variant illustrated in figures 10 and 11 , the four side panels 2 are connected to each other through a bracket coupling. Two panels opposite each other of said four side panels 2 are provided with folded end portions 6 to define a kind of bracket form. The other two side panels 2 are fit below the folded end portions 6 and maintained spaced from each other by the shear panels 3 and by the blocking plate 4.

In the variant illustrated in figures 12 to 15, the four side panels 2 are connected to each other through a comb coupling. The contiguous edges of the side panels 2 are provided with a series of projections 7 which form a kind of comb shape. The projections are folded with respect to the body of the side panel 2 in a manner similar to the folded end portions 6. The projections 7 of a series are inserted between the projections 7 of the other series.

Each of the folded end portions 6 and each of the projections 7 delimits, with the body of the respective side panel 2, an angle “W” equal or substantially equal to the blocking angle “a” of the respective blocking plate 4 (figures 11 and 13).

In the variant illustrated in figures 16 and 17, the four side panels 2 are connected to each other through a coupling welded (visible in figure 17) with a section reduction in order to concentrate the plastic deformations. The side panels 2 are connected by welded connections and two opposite panels 2 possess a section reduction close to the corners which concentrates the plastic deformations, allowing the sides to remain nearly rectilinear. Such section reduction is for example defined by pairs of opposite grooves 16 made on both faces of each of the side panels 2.

In the variant illustrated in figures 18 and 19, the four side panels 2 are connected to each other through a coupling with housing 17 by means of grooves. The grooves can have a trapezoidal shape, allowing a limited rotation of the side panel 2, attaining a hinged connection which allows the side panels 2 to remain nearly rectilinear up to the blocking configuration. In the illustrated embodiment, the housing 17 is made in the upper side panel 2 and in the lower side panel, it has an H shape and houses the edge of the side panels 2 placed adjacent and of the blocking plate 4.

The device 1 is for example inserted in a sub-structure 8 defined by a frame 9 and by diagonal beams 10, 11 connected to vertices of the frame 9 (Braced frame (EBF)) as illustrated in figure 20. Such sub-structure 8 is for example part of a structure of multilevel or multi-floor type 12 like that illustrated in figure 22. The multilevel structure 12 comprises a plurality of sub-structures 8 arranged on each other.

Each sub-structure 8 comprises said frame 9 or portal, a first pair of diagonal beams 10 and a second pair of diagonal beams 11 . Each beam of the first pair of diagonal beams 10 is connected to the frame 9 at a zone close to a vertex of said frame 9. Distal ends 13 of the beams of the first pair of diagonal beams 10 face each other and are mutually connected through the device 1. Each beam of the second pair of diagonal beams 11 has one end connected to the frame 9 at a foot of said frame 9 and an opposite end joined to one of the beams of the second pair of diagonal beams 10 in proximity to the device 1.

The distal ends 13 of the beams of the first pair of diagonal beams 10 are provided with connection plates which are bolted to respective plates defined by two of the side panels 2 of the device 1 (figure 21 ). In the variant of figure 23, such connection plates are welded to two of the side panels 2 of the device 1. In the variant of figure 24, two devices 1 are mutually approached (placed in series) and bolted to each other and the connection plates are each bolded to a side panel 2 of one of the devices 1. The devices 1 in series allow increasing the overall dissipation of energy and/or better control the required drift, considering different limit deformations for each device 1.

The device 1 or the devices 1 illustrated in figures 20 to 24 constitute nodes of a structure with beams.

In the normal work conditions, i.e. when the structure is not stressed by extraordinary phenomena, such as a seismic event, each energy dissipation device 1 is situated in the undeformed or rest configuration illustrated in figures 2, 3, 10-13.

Only the edges with greater angles “b” abut, for example, against the perimeter wall while the sides are spaced from said perimeter wall. The sides of the blocking element 4 define, in the illustrated embodiments, blocking portions 14 of the blocking plate 4. Such sides (blocking portions) 14 are configured for abutting against an abutment portion 15 belonging to the perimeter wall when said perimeter wall reaches a limit deformation configuration, also termed blocked configuration. In the illustrated embodiments, the abutments are defined by an internal surface of the side panels 2 and several of the sides abut against said internal surface of the side panels 2. When the multilevel structure 12 is subjected to a seismic event, the deformations tend to be concentrated at specific zones, at the devices 1 which are configured/programmed to be plastically deformed. Each of the devices 1 (or series of devices 1 ) allows a relative displacement between the distal ends 13 of each first pair of diagonal beams 10 since the perimeter wall and the shear panels 3 are deformable and/or movable with respect to each other when the device 1 is subjected to seismic loads transmitted by the beams 10, 11. The structure allows distributing the forces along predefined paths in the structure itself and controlling the movement/drift between levels/floors of multilevel structures (inter-story drift). The side panels 2 move with respect to each other, losing orthogonality. The perimeter wall takes on a rhombus form, which can have rectilinear or slightly curved sides, the shear panels 3 are deformed and slide with respect to each other and with respect to the blocking plate 4. In this step, the blocking plate 4 is free to move with respect to the perimeter wall. The deformations and the sliding determine energy dissipation. The blocking plate 4 also contributes to preventing buckling phenomena of the shear panels 3.

Two pairs of sides of the blocking plate 4 which delimit a smaller angle or blocking angle “a” approach the respective side panels 2 while the other two pairs move away from the side panels 2. Two of the possible four elements/layers 5 of dissipative material (present in the embodiment of figure 5) are crushed while the other two remain substantially undeformed.

Once a certain deformation has been reached, each of two pairs of contiguous sides of the blocking plate 4 which delimit one of the smaller angles or blocking angles “a” abut against two adjacent side panels 2 (figures 14 and 15). Therefore, contiguous side panels 2 of the perimeter wall delimit an angle equal to an angle between contiguous sides 14 of the blocking plate 4. In the embodiments of figures 10, 11 and 12-15, the connection between the side panels 2 allows their relative rotation until the folded ends 6 or the projections 7 come to be abutted against the adjacent side panel 2. This serves to prevent the side panels 2 from being separated from the shear panels 3 under the diagonal compression applied through the blocking plate 4. A similar behavior is obtained considering the configuration of figures 16 to 19.

In the variant of figure 7, after each of the two pairs of contiguous sides of the central portion of the blocking plate 4 is abutted against two adjacent side panels 2, if the forces involved are very high, the deformation and the rotation continue until auxiliary blocking portions 14’ defined by the sides of the auxiliary plates 18 come to be abutted against the side panels 2. The auxiliary plates 18 can also be more than one per face of the main portion so as to generate a succession of blocking positions.

The blocking plate 4 therefore, in accordance with the method according to the present invention, prevents a further deformation and blocks the device 1 in such limit deformation configuration, wherein the blocking element 4 is substantially fixed with respect to the perimeter wall. The blocking plate 4 therefore works in diagonal compression at specific shear deformation levels of the shear panels 2 and this allows controlling and limiting the drift/movement (drift control) of the multilevel structure 12. The possible elements/layers 5 of dissipative material contribute to maximizing the dissipation and allow a gradual passage to the blocked configuration.

The above-illustrated device 1 can also be employed in structures different from that illustrated above. For example, the structure comprises a plurality of walls and energy dissipation devices 1 are operatively interposed between two adjacent walls For example, the structure comprises a system with walls or rocking separators (rocking wall system) and the energy dissipation devices 1 are operatively associated with said walls.

Figures 25 to 28 illustrate a further embodiment of the device according to the invention. The four side panels 2 are defined by four T shaped sections connected to each other at the respective ends. When the device 1 is assembled (figures 27 and 28), ends of adjacent T shaped sections are connected to each other to define a frame. Each of the T shaped sections has a peripheral wall 19 and a wall 20 projecting towards the interior of the device 1. Two shear panels 3 are joined, for example through bolts, to opposite sides of the wall 20 projecting towards the interior of the device 1. The internal edges of the wall 20 projecting towards the interior of the device 1 and the two shear panels 3 together delimit a single internal housing which houses a single blocking plate 4 of hexagonal shape. The single blocking plate 4 is closed between two shear panels 3. The abutment portions 14 for the blocking plate 4 are defined by the internal edges of the walls 20 projecting towards the interior of the device 1.

Figures 29 to 32 illustrate a variant of the just-described embodiment, in which the side panels 2 are defined by two frames, each formed by four L shaped sections. In particular, ends of four adjacent first L shaped sections are connected to each other to define a first frame, ends of four adjacent second L shaped sections are connected to each other to define a second frame. The two frames are joined to each other, e.g. through bolts, with the interposition of an intermediate shear panel 3. The intermediate shear panel 3 is joined to the walls 20 projecting towards the interior of both frames. Two lateral shear panels 3 are placed on opposite sides of the assembly formed by the first frame, by the second frame and by the intermediate shear panel 3 (figure 31). Also lateral shear panels 3 are joined to the walls 20 projecting towards the interior of both frames. The internal edges of the wall 20 projecting towards the interior of one of the frames, one of the lateral shear panels 3 and the intermediate shear panel 3 together delimit a first internal housing which houses a first blocking plate 4 of hexagonal shape. The internal edges of the wall 20 projecting towards the interior of the other frame, the other lateral shear panel 3 and the intermediate shear panel 3 together delimit a second internal housing which houses a second blocking plate 4 of hexagonal shape Both devices 1 illustrated in figures 25 to 32 can also comprise angle brackets 21 which connect the sections together. Figure 33 illustrates an L shaped angle bracket. Figure 34 illustrates an L shaped angle bracket provided with a curved intermediate portion with convexity directed towards the interior of the device 1. In the configurations illustrated in figures 25 to 34, the peripheral walls 19 can be connected, e.g. through bolts, to further side reinforcement panels 2.

Elements

1 energy dissipation device

2 side panels 3 shear panels

4 blocking plate

5 elements of dissipative material

6 folded end portions

7 projections 8 sub-structure

9 frame

10 first pair of diagonal beams

11 second pair of diagonal beams 12 multilevel structure

13 distal ends of the beams

14 locking portions

14’ auxiliary blocking portions 15 abutment portion

16 grooves

17 housing

18 auxiliary plate

19 peripheral wall 20 projecting wall

21 angle bracket

C center