STRUCTURE OR OBJECT

DESCRIPTION

Field of the invention

The present invention generally relates to the technical field of systems and methods for monitoring and verifying the integrity of structures or articles, and it particularly relates to a system and a method for determining the presence, size and position of cracks and/or deformations.

State of the Art

It is known that civil and non-civil infrastructures and load-bearing structures, such as buildings, viaducts, bridges, tunnels, machined structures, mobile structures or the like require an adequate monitoring of the condition of integrity both to guarantee the structural stability with a high level of safety and to program the maintenance operations that are particularly demanding both in terms of costs and time.

These problems relate to the load-bearing structures described above, load-bearing articles, for example pillars or balconies or balustrades, non-load-bearing articles, for example cornices, and in general any part of structures or articles which could detach from the seat thereof involving anything found at a lower level, for example, another building or an underpass.

A known drawback involving structures or articles in general lies in the onset and progressive increase of integrity-related interruptions and/or defects in, such as cracks and fissures, or the deformations of the structure or article or of part thereof.

This problem is most evident in the event of natural events and not such as telluric movements, floods, fires, avalanches, landslides, mudslides, explosions, overloads. Possibly, should the structure be a viaduct, the change of traffic conditions - for example an increase in the number of vehicles passing through or in the mass thereof - also affects the onset or spread of cracks and fissures.

These problems relate to both new buildings and already existing buildings and, in particular, historical buildings.

When it comes to monitoring cracks, methods and systems which allow to monitor a single crack previously identified and visible on the article or structure are known. When it comes to monitoring deformations, systems consisting of sensors such as for example, strain gauges, inclinometers, accelerometers which allow to verify the deformation condition of individual predetermined points are known. In other words, the known systems therefore allow to monitor individual cracks or deformations previously identified in terms of presence, position and size.

The disadvantage of these known systems and methods lies in that it does not allow to determine the presence of new cracks and/or deformations in the structure or article, and as a result it is not possible to determine the position and size thereof either.

Furthermore, the systems consist of instruments, often active, therefore there is required a specific source of energy supply is required, which must necessarily be installed in proximity of the fissure subject-matter of analysis. The positioning of these instruments requires mechanical fastening to the structure or article such as for example perforations, mechanical anchors and gluing.

A further drawback of known systems lies in that it jeopardises the physical condition of the article both from a performance point of view, introducing crack and/or fissure triggering elements, and aesthetic and preservation, given that the article to be monitored sometimes has values of historical-artistic importance.

Lastly, the systems and methods known today have a significant purchase and installation cost.

Therefore, a further drawback of known systems and methods lies in that it necessarily requires making a discretionary choice as regards which points of the structure or article are to be monitored, thus leaving most of the structure or article without monitoring.

Lastly, known systems and methods are installed in more easily accessible and often less critical locations for cost and time saving reasons. Therefore, disadvantageously, some critical points of the structure are not monitored.

Document US2008223152 discloses a system for detecting the presence of deformations on a wing of an aircraft. This system has the disadvantage of not allowing to monitor medium or large structures. Summary of the invention

An object of the present invention is to at least partly overcome the drawbacks illustrated above by providing a system for monitoring and / or verifying the integrity of a structure or article that is highly efficient and cost-effective.

An object of the present invention to provide a system for monitoring and / or verifying the integrity of a structure or article which allows to determine the presence of cracks and/or deformations.

An object of the present invention to provide a system for monitoring and/or verifying the integrity of a structure or article which allows to determine the size and/or position of cracks and/or deformations.

An object of the present invention to provide a system for monitoring and / or verifying the integrity of a structure or article that is particularly versatile.

An object of the present invention to provide a system for monitoring and/or verifying the integrity of a structure or article that does not damage the structure or article.

An object of the present invention to provide a system for monitoring and/or verifying the integrity of a structure or article with particularly large dimensions.

An object of the present invention to provide a system for monitoring and/or verifying the integrity of a structure or article having a length greater than 50 metres, preferably greater than 100 metres.

An object of the present invention to provide a system for monitoring and/or verifying the integrity of a structure or article with complex geometry.

An object of the present invention to provide a system for monitoring and/or verifying the integrity of a structure or article in a simple and quick manner.

A further object of the present invention is to provide a method for monitoring and/or verifying the integrity of a structure or article that is highly efficient and cost- effective.

Another object of the present invention to provide a method for monitoring and/or verifying the integrity of a structure or article that allows to determine the presence, size and/or position of cracks and/or deformations.

Another object of the present invention to provide a method for monitoring and/or verifying the integrity of a structure or article that is versatile, simple and quick.

These and other objects that will be more apparent hereinafter, are attained by a method and by a system as described, illustrated and/or claimed herein.

The dependent claims describe advantageous embodiments of the invention.

Brief description of the drawings

Further characteristics and advantages of the invention will be more apparent in light of the detailed description of a preferred but non-exclusive embodiment of the invention, illustrated by way of non-limiting example with reference to the attached drawings, wherein:

FIG. l is a schematic view of a system 1;

FIG. 2 is a schematic view of a pillar S with the system 1;

FIG. 3 is a schematic view of a bridge S with the system 1;

FIG. 4 is a partially cross-sectional schematic view of a room S with the system 1.

Detailed description of a preferred embodiment

With reference to the aforementioned figures, herein described is a system 1 for monitoring and/or verifying the integrity of a structure or article S.

In particular, the structure S may be a fixed load-bearing structure, for example a building, a building apartment, a viaduct, a bridge, a tunnel, a movable load-bearing structure, for example a lifting machine, scaffolding or the like, or a non-load-bearing structure such as for example a cornice. On the other hand, the article S may be a part of a structure or an individual structural element, for example a column, balcony or balustrade, or non-structural, for example an ornamental column, a window sill or the like.

Possibly, the structure may be part of a machine, for example a forklift truck or it may be a reinforcement structure, for example a scaffolding, or it may be part of a vehicle, for example the wing of an aeroplane.

Preferably, the structure S or the article may be particularly large in size. For example, such linear dimensions (height or width or length) may be greater than 20 m, preferably greater than 50 m and even more preferably greater than 100 m.

FIG. 2 shows an article S having the shape of a pillar. In this case, the system 1 may have an extension along only one direction (length).

However, the system 1 may have an extension along two directions (length and width), for example in the case of a floor, ceiling, bridge or the like, or an extension along three directions (length, width and height), for example in the case of a building or a lifting machine.

It is clear that these embodiments are examples. As a matter fact, the system 1 may be implemented on any type of structure or article S along different directions depending on the needs.

Preferably, the system 1 may be particularly suitable for medium-sized structures S, that is structures having an extension along a direction comprised between 50 and 100 metres. Examples of these structures S are building apartments, bridges and viaducts, pillars supporting the latter, facades, skyscrapers. Examples of large manufactured articles or machines S are lifting cranes, overhead cranes or the like.

The system 1 may also be particularly suitable for use in large structures S, that is structures extending along a direction greater than 100 metres, for example comprised between 300 and 1000 metres, like in the case of a viaduct.

Essentially, the system 1 may comprise a conductive path 10, a plurality of modules 20 arranged along the conductive path 10 in a plurality of predetermined positions P to detect one or more information, and a receiving unit 30 to receive information from at least one of the modules 20.

Preferably, as better explained hereinafter, the receiving unit 30 may receive information relating to all the modules 20, that is relating to all the positions P.

The conductive path 10 may be obtained in any manner, for example it may be a conductive cable. Preferably, the conductive path 10 may be part of or it may define a circuit within which electric current flows through.

For example, as schematically illustrated in FIG. 1, the path 10 may comprise a single cable having both ends operatively connected to a same voltage generation unit 19.

Possibly, the path 10 may be pre-assembled and subsequently positioned on the structure or article S.

Preferably, the conductive path 10 may be obtained with conductive paint. In other words, the path can may be obtained with a continuous strip of conductive paint. The type of conductive paint, same case applying to the width of the strip, may be of different types and size depending on the needs.

The path 10 may be traversed by electric current at very low voltage (for example lower than 50 V in A.C.) so that the system is safe for any application and not harmful to humans or animals.

The path 10 may be suitably "electrically insulated" from the article or structure S and from the external environment to avoid any kind of alteration in the detection of the electrical resistance as described below.

It is clear that the path 10 may be substantially integrally joined with the structure or article. The path 10 may be internal or installed on the surface.

Advantageously, the system 1 subject of description may allow the installation of the path 10 without damaging the structures or the articles S. As a matter fact, the system 1 may be installed on the structure or article without using invasive mechanical techniques, for example anchors, and/or chemical techniques, for example glues.

This will allow to prevent the triggering of cracks and fissures in the article or structure due to the installation of the system 1.

Furthermore, due to these characteristics, the system 1 may be installed also in buildings subject to historical/architectural restrictions and in general on any structure or article that requires particular attention.

Furthermore, the system 1 may be particularly small in size. For example, should conductive paint be used to produce the path 10, the latter may have a thickness in the order of the thickness of a paper sheet.

Furthermore, the system 1 particularly versatile and may be installed on existing structures or articles, on new articles (prefabricated and non-prefabricated) and it may be installed on structures or articles made of different conductive or non-conductive materials (for example, concrete, wood, metal, plastic elements, glass).

The system 1 may be modular. As a matter fact, once the system 1 has been installed on the article or structure, the path 10 can be subsequently modified or extended depending on the preferences. For example, should the structure be modified, or if there arises the need to monitor or verify a part of the structure more accurately.

The path 10 may be particularly easy to install and the use of specialised personnel may not be necessary. Therefore, the system 1 may be generally simple and quick to install. Also the maintenance and modification operations of the path 10 may be particularly simple and quick to carry out.

Suitably, the conductive path 10 may therefore have at least one section 11 and one section 12 facing each other, preferably substantially parallel to each other. Preferably, but not exclusively, each section 11, 12 may be obtained by means of conductive paint.

In particular, the conductive path 10 may comprise a plurality of connection bridges 15 for connecting the section 11 and the section 12. In other words, the path 10 may be shaped to form a track with two substantially parallel sections 11, 12 and a plurality of crosspieces, that is the bridges 15, which are transversal to the sections 11, 12.

Therefore, the conductive path 10 may comprise a plurality of circuits 10', each comprising a bridge 15, all connected with the same voltage generation unit 19.

Suitably, the modules 20 may be positioned along the conductive path 10 and they may be operatively connected therewith. Preferably, the modules 20 may be positioned at the connection bridges 15. Even more preferably, each module 20 may be positioned at a connection bridge 15. In other words, each module 20 may be positioned at a circuit 10'.

Each module 20 can be configured to detect the electrical resistance of the corresponding connection bridge 15 and therefore the electrical resistance of each of the internal circuits 10' of the path 10.

It is clear that the modules 20 may further comprise a battery 22 for power-supplying the unit 24 suitable to send/receive the signals. Therefore, the system 1 may remain active even in the event of a power outage, like in the event of an earthquake, or in the event of a power failure, like in the proximity of motorway pillars.

The modules 20 may further comprise means for detecting the electrical resistance at a position of the known type. Possibly, these means may be power-supplied by the battery 22 and/or by the path 10.

Essentially, the system 1 may therefore determine the presence, position and/or size of cracks or dilatations starting from the resistance values detected by the modules 20. In particular, the system 1 may be based on the variation of the electrical resistance of the path 10 and in particular of one or more of the circuits 10' in the path 10. To this end, each module 20 may therefore comprise an appropriate unit configured to detect the electrical resistance at the predetermined installation position P. The resistance detection unit may be an integrated loT node capable of converting, storing and transmitting data, for example to other adjacent modules 20 and/or to the receiving unit 30 as better described below.

The electrical resistance is defined by the known function:

R= V/l where:

R is the resistance between the ends of the path 10;

V is the voltage applied to the two ends of the path 10;

I is the current intensity that flows through the path 10.

The resistance of a conductor section is expressed by the following equation: R=p*(L/S) where:

L is the length of the path;

S is the area of the section of the path; p is the electrical resistivity of the material (also called specific electrical resistance), measured in ohms/metre.

Therefore, a variation of the resistance value may be detected as the length of the circuit 10' varies due to a deformation (not necessarily linear and which does not entail the disconnection/interruption of the path, but it entails the modification of the cross-section thereof).

Possibly, the deformation of the circuit 10' may be measured in another manner, for example by detecting the modification of the lattice or other morphological characteristic (like in the case of use of graphene), without departing from the scope of protection of the present invention.

For example, in the case of deformation, the section 11 of the path at a circuit 10' may be extended, thus changing the corresponding resistance value detected by the corresponding module 20. Suitably, as better described below, the receiving unit 30 may receive operational data relating to all the modules 20 so as to determine not only the presence, but also the position and/or size of cracks or dilatations.

To this end, the system 1 may comprise a data processing logic unit 40 operatively connected to the receiving unit 30 to process the data received from the latter and, for example, to determine the presence, position and/or size of cracks or dilatations.

The logic unit 40 may be operatively connected to the receiving unit 30 in wired or wireless mode. Possibly, the logic unit 40 may be connected remotely. A storage unit for storing such operational data received from the receiving unit 30 may be possibly provided for. This storage unit may be operatively connected to the receiving unit 30 and the logic unit 40 in wired, wireless or remote mode in a per se known manner.

Advantageously, the modules 20 may be mutually connected in wireless mode. The modules 20 may have a radius of action r, that is a maximum distance for transmitting the signal effectively, that is such that it can be received by another module or by the receiving unit 30.

Suitably, each module 20 may have a mutual distance d equal to or less than the radius of action r from one or more modules 20 which may define the adjacent modules of the module 20. It is therefore clear that, similarly, each position P may have a distance equal to or smaller than the radius of action r from at least one adjacent position P.

Preferably the radius of action r may be about 20 - 40 metres. However, it is clear that this radius of action r may vary depending on the communication technology applied.

The radius of action r, same case applying to the distance d may vary from one module to another module. Preferably, but not exclusively, the modules may be identical to each other and substantially equally spaced.

According to a preferred but not exclusive embodiment, the modules 20 may be operatively connected by means of Bluetooth® GSM, LAN technology, or, even more preferably, by means of BLE (Bluetooth Low Energy) technology.

In this case, the radius r may be about 30 m. In this case, the distance d between the modules 20 may for example be about 20-25 m.

Essentially, the module 20 may receive and send signals. In particular, advantageously, each module may receive a signal and it may send a signal which comprises the received signal.

Suitably, each module 20 may receive the signals from one or more adjacent modules and it may send it to one or more adjacent modules. It is clear that should a module 20 have a single adjacent module, the former may receive and send the signals only to the latter.

This characteristic may allow to form a "chain" and therefore the track 10 may have a particularly considerable length LU.

The length LU may be greater than 5 metres, preferably greater than 10 metres, so as to be particularly suitable for small structures or articles S.

The length LU may be greater than 50 metres, preferably comprised between 50 and 100 metres so as to be particularly suitable for medium-sized structures or articles S.

The length LU may be greater than 100 metres, preferably comprised between 300 and 500 metres so as to be particularly suitable for large structures or articles S.

In greater detail, at least one module 20 may have a distance dl from the receiving station 30 smaller than the radius of action r and at least one module 20 may have a distance d2 from the receiving unit 30 greater than the radius of action r.

Preferably, a single module 20 may be at a distance dl from the receiving unit 30, while all the other modules 20 may have a distance d2 greater than the radius of action r from the receiving unit 30.

The last module 20, that is the one arranged at a distance dl from the receiving unit 30, may send the signal to the latter.

In other words, not all modules 20 may be connected directly with the receiving unit 30 to send a signal directly to the latter.

In this manner, the length LU of the path 10, that is the maximum distance of a module 20 from the receiving unit 30, may be greater than the radius of action r.

Preferably, the system 1 may comprise a single receiving unit 30. It is clear that a plurality of receiving units 30 may be provided for in the case of paths having a particularly high extension or a considerable length LU.

Suitably, the signal received by each module may contain operational data relating to all the previous modules. On the other hand, the signal sent by each module may contain information relating to the module and the information received, that is all the information relating to the previous modules.

Thanks to this characteristic, the receiving unit 30 may receive a signal containing information relating to one or more modules 20 arranged at the distance d2, preferably of all the modules 20 of the system 1.

Furthermore, thanks to these characteristics, the path 10 may have a length LU much greater than the radius of action r, while the receiving unit 30 may also receive information relating to all the modules 20.

The signal sent by each module 20 may comprise the resistance value detected by the module 20 at the relative position P and an identification code of the module 20. In greater detail, the detected resistance value may be associated with a unique identification code of the respective module 20 so as to define an operational data packet sent by means of the signal.

It is clear that should the path 10 be substantially linear-shaped, there may be defined several modules in which each module receives the signal from a single module containing the operational data of all the previous modules and sends a signal to a subsequent single module containing the operational data of all previous modules and the operational data of the module.

Suitably, the modules 20 may be positioned in series so as to have a pair of end modules 20, one of which is arranged at the distance dl from the receiving unit 30. The intermediate modules between the pair of end modules 20 may have a previous single module and a subsequent single module.

Preferably, each module may have a distance d from the adjacent module and a distance d3 from the subsequent module to the adjacent module greater than the radius of action r.

Therefore, the path 10 may have a particularly considerable length LU, while using a minimum number of modules 20 at the same time.

On the other hand, should the path 10 have branches or be "mesh-shaped", a module may receive signals from several modules and/or it may send the signal to several modules. Due to the presence of the identification code associated with the resistance value, it does not matter how many times the signal is bounced between the modules 20, provided that it reaches the receiving unit 30. The module and the corresponding resistance value may therefore be identified by means of the logic unit 40 in order to determine the presence of deformations or cracks as better described below.

Suitably, the system 1 may comprise a plurality of modules 20 operatively connected by means of the so-called "BLE Mesh" technology which may allow the information to be transmitted from the monitored element, that is from a module 20, to any point of the structure or article, that is to another module 20 or receiving unit 30 at a distance smaller than the radius of action r, given that the very modules 20 allow to detect and transmit the data.

In particular, the use of BLE technology, may allow the modules 20 to receive and transmit signals with low energy consumption. Thanks to this characteristic, the system 1 may be particularly long-lasting and the battery may be sufficient to allow the operation of the modules 20 and therefore the system 1 to operate independently. Possibly, the battery may be used only in the event of a malfunction/catastrophic event, while the modules 20 may be powered by the path 10.

Due to these characteristics, the path 10 may have a particularly considerable extension both in terms of distance from the receiving unit 30, that is length LU, such as for example in the case of a bridge S or pillar S, and in terms of branching and geometric complexity, like in the case of a skyscraper S.

In any case, the receiving unit 30 downstream of the modules 20 may receive all the operational data relating to the modules 20 and in particular, due to the resistance values and to the associated identification code, it may be possible to determine at which point or at which points of the path 10 and therefore of the article S there is a crack or fracture.

The possible presence of deformations may be operatively determined starting from a detection of a change of resistance at one or more parts of the path 10.

Furthermore, the identification code of the module 20 associated with the resistance values, may allow to determine which module 20 detected this change in value and therefore the position of the deformation.

Lastly, the size of the deformation may also be determined should several modules 20 detect a change in the resistance value.

On the other hand, the method may allow to determine the possible presence of cracks, which may correspond to the interruption of one or more circuits 10' (that is a resistance value substantially undefined or equal to 0).

Similarly, the identification code of the module 20 associated with the resistance values may allow to determine which module 20 detected this value and therefore also the position of the crack.

Lastly, the size of the crack may also be determined should several modules detect such resistance value indicating the interruption of the circuit.

Advantageously, the modules 20 may continue to send signals even when the circuit or more circuits are interrupted. In this case, the modules may be power-supplied for example by the battery 22. This characteristic may allow to detect the presence of a plurality of cracks and/or deformations.

Furthermore, the number of possible cracks and/or deformations that can be detected may depend on the configuration of the path 10, for example if it consists of a single rectilinear track with the modules in series or if it has a plurality of branches or a "mesh" structure.

Therefore, these characteristics may allow to intervene or program the maintenance of the structure or article suitably and avoid risks of collapse or failure thereof.

According to a particular aspect of the invention, the modules 20 may comprise a suitable unit for detecting other data, such as for example temperature, humidity and/or acceleration at the respective position of the module 20.

Similarly to the data relating to resistance, these data may also be received and sent by associating the code with the respective module 20 at which the data were detected. In other words, such data may also be part of the operational data packet.

Therefore, this characteristic may allow to measure, possibly memorise, the number of mechanical stresses, oscillations and vibrations to which a single module 20 or the article or structure is subjected to within a time interval, possibly during the entire period of time over which the system 1 is installed.

Furthermore, the system 1 may allow to provide a precise indication for preventing fatigue failures starting from the detected acceleration and deformation data, and therefore from the values calculated starting from the latter relating to stress, number of cycles and frequency. Furthermore, besides the number of loading-unloading cycles, it may also be possible to know the maximum stress reached for each cycle.

It is clear that such data may be processed by the data processing unit 40 similarly to the data relating to the electrical resistance described above.

The system 1 may therefore allow to monitor or verify the integrity of a structure or article not only by determining the presence, size and/or position of cracks or deformations, but also by determining the stresses and the risk of fatigue failure.

As known, fatigue fractures are considered to be the most dangerous type of fracture of mechanical and non-mechanical components, given that they occur without excessive loads and under standard operating conditions. As a matter fact, the structural elements, subjected to stresses cyclically variable over time, may collapse at load levels even significantly lower than the static resistance.

When designing structures and articles one must therefore pay particular attention to the fatigue phenomenon. This attention is greater in the case of structures and articles subjected to a considerable flow of stresses.

Furthermore, it is clear that in the case of structural structures or articles, this aspect is particularly important.

Therefore, this system 1 may therefore be particularly advantageous for applications such as bridges, viaducts, tunnels on which trains or vehicles pass, for buildings in seismic areas, for plants or sheds comprising movement machinery.

A particular application of this system 1 is in the field of particular articles, such as lifting machines, such as for example overhead cranes, telescopic systems, cranes, lifting, handling and transportation systems in general, in which it is of fundamental importance to know the cycles carried out and therefore to evaluate the residual life or the maintenance schedule.

Another application is to measure the deformation reached, the loading-unloading cycles, the frequency, the tension reached by a given component of the structure or article, such as for example the wing of an aircraft, the axle of a means of transportation by road or railway, the hull of a boat, protection barriers, trade fair installations or other mechanical components.

The data processing unit 40 may implement artificial intelligence and machine learning processes. This may allow to identify, process and compensate the results that can be affected and that are affected by external factors such as vibrations, humidity, temperature, extraordinary events such as landslides and telluric movements, thus ensuring the maximum accuracy and traceability of the detected and/or calculated data.

For example, this characteristic may allow to correct the data detected if the path 10 or part thereof is subjected to significant temperature changes, exposed to solar radiation or other conditions.

Furthermore, the system 1 may automatically manage alarm thresholds and send alert messages by means of emails, SMSs, calls or smartphone notifications.

The system 1 may further comprise means for sending acoustic and light signals and means for sending activation signals for safety mechanisms installed in proximity of the structure under analysis of the per se known type, for example traffic lights, flashing lights, warning sirens, closing bars.

Furthermore, thanks to the artificial intelligence system, the system 1 may independently learn possible false alarms, or situations of accidental change not due to a specific problem of the structure or article.

Possibly, the system 1 may store only some of the data detected by the modules 20. For example, data relating to modules 20 arranged in positions in proximity of deformations may be stored more frequently and data relating to modules far from deformations may be stored less frequently.

Possibly, also the modules 20 may be provided with artificial intelligence and they may be capable of self-learning - through machine learning proprietary algorithms - the characteristics of the structure or of the article and of the related events and therefore make the system 1 particularly efficient.

It is clear that the system may be stably installed on a structure or article and the system may be configured so that it detects the data substantially continuously and/or stores the data continuously and/or processes the data continuously so as to continuously monitor the structure or article. This configuration is preferred when machine learning processes are used.

On the other hand, the system 1 may be used discontinuously and it may be selectively activated by an operator. In other words, the integrity of the structure or article may be verified whenever required or at regular scheduled intervals.

In light of the above, it is clear that the invention attains the pre-set objectives.

The invention is susceptible to numerous modifications and variants. All details may be replaced by other technically equivalent elements, and the materials can be different depending on the technical needs, without departing from the scope of protection of the invention defined by the attached claims.