Sears, Kenneth John (The Grange Bressingham Norfolk IP22 2AT, GB)
Tate, Michael (8 Waveney Drive Belton Great Yarmouth Norfolk NR31 9JU, GB)
Sears, Kenneth John (The Grange Bressingham Norfolk IP22 2AT, GB)
| 1. | i. An energy absorber for absorbing energy of an impact therewith by a moving object comprising: a wall which defines in the energy absorber a groove or cavity; and anchoring means for anchoring the energy absorber to a stationary structure or to the ground; wherein: the wall is composed of a composite material having fibres set in a resin; the wall can be crushed when the moving object impacts the energy absorber, the crushing of the wall absorbing energy of the impact; during crushing the wall of the energy absorber disintegrates with the resin separating from the fibres set therein; and wherein the wall has: a root portion adjacent to the anchoring means; a tip portion which is spaced apart from the root portion and which is located nearer a potential impact point when the anchoring means anchors the energy absorber to the stationary structure or to the ground; and a middle portion which extends from the root portion to the tip portion; characterised in that: the groove or the cavity in the energy absorber has a crosssectional area which increase gradually from the tip portion of the wall to the root portion of the wall ; the wall has a thickness which increases gradually from the tip portion thereof to the root portion thereof; and during crushing the wall of the energy absorber disintegrates progressively with the tip portion disintegrating first and then the middle portion and lastly the root portion. |
| 2. | An energy absorber as claimed in claim 1, wherein the anchoring means comprises a mount having a first end and a second end, the first end having a socket with a profile which corresponds to the profile of the root portion, the socket being sized to hold the root portion securely therein, and a second end which is securable to the stationary structure or the ground. |
| 3. | An energy absorber as claimed in claim 2, wherein the mount comprises fixing means to hold the root portion of the wall of the energy absorber within the socket of the mount. |
| 4. | An energy absorber as claimed in claim 3, wherein the fixing means comprises bonding agents and/or securing screws or pins, the bonding agents being concrete, glue, or any other such adhesive substance. |
| 5. | An energy absorber as claimed in claim 1, wherein the root portion of the wall of the energy absorber comprises apertures and the anchoring means comprises pins and/or screws inserted through the apertures to secure the wall to the stationary structure or the ground. |
| 6. | An energy absorber as claimed in any one of the preceding claims, wherein the wall comprises longitudinal fibres which extend along the wall from the root portion means towards the tip portion. |
| 7. | An energy absorber as claimed in claim6 wherein all of the longitudinal fibres extend from the root portion, the longitudinal fibres being arranged in bundles of different lengths, some of the fibres extending to the tip portion and the rest being of graduated length so as to stop short of the tip portion. |
| 8. | An energy absorber as claimed in claim 7 wherein each bundle of longitudinal fibres is arranged so that each fibre lies side by side to form a layer of defined length and each bundle forms a separate layer of a different length. |
| 9. | An energy absorber as claimed in any one of claims 6 to 8 wherein the wall comprises additionally multidirectional fibres distributed along the length of the energy absorber. |
| 10. | An energy absorber as claimed in claim 9 wherein the multidirectional fibres are present in a mat set in the resin material. |
| 11. | An energy absorber as claimed in claim 8 or claim 9 wherein the multidirectional fibres are provided near an exterior surface of the wall of the energy absorber. |
| 12. | An energy absorber as claimed in claimed in any one of claims 9 to 11 wherein in the tip portion of the energy absorber the percentage of the wall which comprises the multidirectional fibres is greater than the percentage of the wall comprising the multidirectional fibres in the root portion. |
| 13. | An energy absorber as claimed in any one of claims 9 to 12 wherein in the root portion of the wall of the energy absorber the percentage of the wall which comprises longitudinal fibres is greater than the percentage of the wall comprising the longitudinal fibres in the tip portion. |
| 14. | An energy absorber as claimed in any one of the preceding claims which is formed as a single piece hollow moulding with a cavity extending therethrough. |
| 15. | An energy absorber as claimed in claim 14 wherein the cavity is of generally square cross section. |
| 16. | An energy absorber as claimed in claim 14 wherein the cavity is of generally rectangular crosssection. |
| 17. | An energy absorber as claimed in claim 14 wherein the cavity is of generally circular cross section. |
| 18. | An energy absorber as claimed in any one of claims 1 to 13 comprising two moulded portions each having a groove, whereby when the moulded portions are joined together the grooves in the moulded portions cooperate together to define a cavity extending along the energy absorber. |
| 19. | An energy absorber as claimed in claim 18 wherein the grooves are each Ushaped and together define a square crosssection cavity. |
| 20. | An energy absorber as claimed in claim 18 wherein the grooves are each Ushaped and together define a rectangular crosssection cavity. |
| 21. | An energy absorber as claimed in claim 18 wherein the grooves are each of semicircular section and together define a circular crosssection cavity. |
| 22. | An energy absorber as claimed in any one of claims 18 to 21 wherein each moulded portion has two flanges adjacent the groove therein and the flanges of one moulded portion are adhered facing flanges of the other moulded portion. |
| 23. | An energy absorber as claimed in any one of claims 1 to 13 comprising two corrugated moulded portions each having a pair of parallel spaced apart grooves which when the moulded portions are joined together form a pair of parallel extending cavities. |
| 24. | A pair of parallel spaced apart energy absorbers as claimed in claim 23 wherein the grooves are both Ushaped and together define square cross section cavities. |
| 25. | A pair of parallel spaced apart energy absorbers as claimed in claim 23 wherein the grooves are both Ushaped and together define rectangular crosssection cavities. |
| 26. | A pair of parallel spaced apart energy absorbers as claimed in claim 23 wherein the grooves are both of semicircular section and together define circular section cavities. |
| 27. | An energy absorber as claimed in any one of claims 23 to 25 wherein the moulded portions each have flanges adjacent the grooves therein and the flanges of one moulded portion are adhered facing flanges of the other moulded portion. |
| 28. | An energy absorber as claimed in any one of claims 1 to 13 comprising a moulded portion having a groove and a panel joined to the moulded portion, the panel having a generally flat surface which defines with the groove a cavity extending along the energy absorber. |
| 29. | An energy absorber as claimed in claim 29 wherein the groove is Ushaped and defines with the generally flat surface a square crosssection cavity. |
| 30. | An energy absorber as claimed in claim 28 wherein the groove is Ushaped and defines with the generally flat surface a rectangular crosssection cavity. |
| 31. | An energy absorber as claimed in claim 28 wherein the groove is semicircular and defines with the generally flat surface a semicircular cross section cavity. |
| 32. | An energy absorber as claimed in any one of claims 1 to 13 comprising a moulded portion having a pair of parallel extending grooves and a panel joined to the moulded portion, wherein the panel has a generally flat surface which defines with the grooves a pair of spaced apart cavities extending along the energy absorber. |
| 33. | A pair of parallel extending grooves in an energy absorber as claimed in claim 32 wherein the grooves are Ushaped and define with the generally flat surface square crosssection cavities. |
| 34. | A energy absorber as claimed in claim 32 wherein the grooves are Ushaped and define with the generally flat surface rectangular crosssection cavities. |
| 35. | An energy absorber as claimed in claim 32 wherein the grooves are semicircular and define with the generally flat surface semicircular cross section cavities. |
| 36. | An energy absorber as claimed in any one of claims 28 to 35 wherein the panel is adhered to the moulded portion by an adhesive which permits the panel to peel away from the moulded portion as the moulded portion disintegrates during impact. |
| 37. | An energy absorber as claimed in claim 36 wherein the moulded portion has flanges to which the generally flat surface of the panel is adhered to join the moulded portion to the panel. |
| 38. | An energy absorber as claimed in claim 37 wherein the generally flat surface is slightly corrugated at least in those regions of the panel which are adhered to the flanges, the corrugations in the generally flat surfaces leaving areas where the adhesive does not interconnect the flanges and the panel, with such areas acting to impede the spread of cracks through the adhesive. |
| 39. | A stationary structure comprising the energy absorber as claimed in any of the preceding claims. |
| 40. | A stationary structure as claimed in claim 39 wherein the stationary structure is a railway terminus buffer, a parking bollard, a vehicle highway barrier or is a device used in the base of lift shafts to absorb the impact of a falling lift. |
| 41. | A method of installing the energy absorber of any one of claims 1 to 38 comprising the steps of making a cavity in the stationary structure or the ground suitable for the anchoring means of the energy absorber to be securely placed therein, and securing the anchoring means of the energy absorber therein. |
| 42. | A method as claimed in claim 41 further comprising the step of providing a bonding substance between the anchoring means of the energy absorber and the cavity in the stationary structure or the ground to secure the anchoring means in the cavity. |
| 43. | A method as claimed in claim 42 wherein the bonding substance may be concrete, glue, or any other such adhesive substance. |
| 44. | A method as claimed in any one of claims 41 to 43 wherein the cavity in the stationary structure is made during manufacture of the stationary structure. |
| 45. | A method of installing the energy absorber of claim 2 wherein the root portion of the wall of the energy absorber is secured in the first end of the mount and the second end of the mount is mounted to the stationary structure or to the ground. |
| 46. | 45 A method as claimed in claim 45 wherein a bonding agent is provided between the mount and the stationary structure or the ground. |
| 47. | A method of installing the energy absorber of claim 5 wherein pins and/or screws are inserted through the apertures in the root portion of the wall of the energy absorber to secure the wall in position. |
Although energy absorbers, e. g. buffers, are known in the art, they are often made of metal and have a high tendency to buckle on impact, for example, motorway central reservation barriers.
Such modes of failure are not only relatively difficult to predict quantitatively, often resulting in expensive mechanical testing, but can also result in reduced safety. Reduced safety is linked to debris being thrown out in unpredictable directions during failure under buckling.
The present invention provides an energy absorber for absorbing energy of an impact therewith by a moving object comprising: a wall which defines in the energy absorber a groove or cavity; and anchoring means for anchoring the energy absorber to a stationary structure or to the ground; wherein: the wall is composed of a composite material having fibres set in a resin; the wall can be crushed when the moving object impacts the energy absorber, the crushing of the wall absorbing energy of the impact; during crushing the wall of the energy absorber
disintegrates with the resin separating from the fibres set therein; and wherein the wall has: a root portion adjacent to the anchoring means; a tip portion which is spaced apart from the root portion and which is located nearer a potential impact point when the anchoring means anchors the energy absorber to the stationary structure or to the ground; and a middle portion which extends from the root portion to the tip portion; characterised in that: the groove or the cavity in the energy absorber has a cross-sectional area which increase gradually from the tip portion of the wall to the root portion of the wall; the wall has a thickness which increases gradually from the tip portion thereof to the root portion thereof; and during crushing the wall of the energy absorber disintegrates progressively with the tip portion disintegrating first and then the middle portion and lastly the root portion.
The energy absorber of the present invention is designed not to buckle but instead gradually disintegrate during impact. Furthermore, composite materials are used in favour of the more traditional steel. Advantageously, the energy dissipation during crushing of the composite material used compares favourably with steel. Specifically, steel has a typical value of 5J/g (energy dissipated per unit mass), whilst the composite material has a typical value of 35J/g. Thus, the invention permits the use of 6kg of composite material in place of
35kg of steel.
The present invention also provides a stationary structure comprising the energy absorber described above. The stationary structure may be railway terminus buffers, parking bollards, vehicle highway barriers and may be a device used in the base of lift shafts to absorb the impact of a falling lift. The man skilled in the art would appreciate that the invention could be applied to other similar stationary structures.
The energy absorber comprises anchoring means to secure the anchoring means of the energy absorber to the stationary structure or to the ground.
Preferably the anchoring means comprises a mount having a first end and a second end, the first end having a socket with a profile which corresponds to the profile of the anchoring means, the socket being sized to hold the anchoring means securely therein, and a second end which is securable to the stationary structure or the ground.
The anchoring means may also comprise fixing means to hold the wall of the energy absorber within the socket of the mount. The fixing means could comprise bonding agents and/or securing screws or pins. The bonding agents may be concrete, glue, or any other such adhesive substance.
In another embodiment the root portion of the wall may also comprise apertures and the anchoring means comprise pins and/or screws inserted through the apertures to secure the wall in position.
In a further embodiment the invention provides a method of installing the energy absorber comprising the steps of making a cavity in the stationary structure or the ground suitable for the anchoring means of the energy absorber to be securely placed therein, and placing the mount of the anchoring means therein. The method may further comprise the step of providing a bonding substance between the mount and the cavity in the stationary structure or the ground to secure the anchoring means in the cavity. The bonding substance may be concrete, glue, or any other such adhesive substance and the cavity in the stationary structure may be made during manufacture of the stationary structure.
The invention also provides a further method of installing the energy absorber wherein the root portion of the wall of the energy absorber is secured in the first end of the mount and the second end of the mount is mounted to the stationary structure or to the ground. The method may also comprise the step of providing a bonding agent between the mount and the stationary structure or the ground.
In addition, the invention provides another method of installing the energy absorber wherein the anchoring means comprises pins and/or screws which are inserted through apertures in the root portion of the wall of the energy absorber to secure the energy absorber in position.
Various embodiments of the invention will now be described by way of an example only, with reference to the accompanying drawings in which:
Figure 1 is schematic view of a pair of energy absorbers of the present invention used as railway terminus buffers.
Figure 2 is a perspective view of one of the energy absorbers shown in Figure 1; Figure 3 is a cross-section through the energy absorber of Figure 2; Figure 4 is an exploded perspective view showing the arrangement of fibres in a tip portion of a wall of the energy absorber of Figures 2 and 3; Figure 5 is an exploded perspective view showing the arrangement of fibres in an anchoring means of a wall of the energy absorber of Figures 2 and 3.
Figure 6 is a schematic view illustrating the arrangement of longitudinal fibres in the core of a wall of the energy absorber according to the present invention; Figure 7 is a perspective view of a second embodiment of the energy absorber according to the present invention; Figure 8 is a perspective view of a third embodiment of the energy absorber according to the present invention; Figure 9 is a perspective view of a fourth embodiment of the energy absorber according to the present invention; and Figure 10 is a perspective view of the energy absorber of Figure 9 in a particular configuration.
Figure 1 shows a railway terminus buffer 10 comprising anchoring means in the form of a mount 11. The mount 11 can be part of any stationary structure which includes the railway terminus buffer of Figure 1, and also parking bollards and vehicle
highway barriers. The man skilled in the art would appreciate that the invention could se applied to other similar stationary structures, including being used in the base of lift shafts to absorb the impact of a falling lift.
Secured to the mount 11 and extending forward of the mount 11 are two energy absorbers 20. These energy absorbers 20 extend one either side of the mount 11 and are flared outwardly slightly (i. e the distance between the two energy absorbers 20 at the mount 11 is less than the distance between the two energy absorbers 20 away from the mount 11). This helps the energy absorbers 20 together deal with offset impact. In addition, the forwardmost ends of the energy absorbers 20 can be connected together by a bumper (not shown), to which they are both attached.
Each energy absorber 20 is composed of composite material comprising fibres arranged in a resin matrix (e. g. a matrix of epoxy or polyurethane resin). The composite material is described in detail below.
As can be seen in Figure 2, each energy absorber 20 is hollow and has a cavity of a square or rectangular transverse cross-section. The cross- sectional area of the cavity of each energy absorber 20 tapers linearly from a largest cross-section at a root portion 22 of the energy absorber 20 adjacent the mount 11 to a smallest cross-section at the forward most tip portion 21 of the energy absorber 20. Furthermore, as is illustrated in Figure 3, the wall thickness 5 of an energy absorber 20 tapers
linearly from a largest wall thickness o at the anchoring means 22 to a smallest wall thickness o at the tip portion 21.
Typically the energy absorber 20 will be 600 to 700 millimetres long and the wall thickness 5 will decrease from a maximum of 6 millimetres in the anchoring means 22 to a minimum of 2.5 millimetres in the tip portion 21.
In Figures 4 and 5, there can be seen respectively tip 21 and root 22 portions of a wall of a energy absorber 20. The wall is composed of a composite material comprising a plurality of layers 25,26,27,28 of fibres arranged in a resin matrix.
Layers 26,27,28 of fibrous matting are provided near the exterior surface of the energy absorber 20 and layers 25 of glass fibres in the centre.
The longitudinal fibres in the layers 25 are all orientated to run lengthwise along the tapering walls of the energy absorber 20, each extending from the anchoring means 22 toward the tip portion 21.
The longitudinal fibres in layers 25 in the core are of different lengths and are arranged in bundles (tows) so as to form layers of different lengths.
All of the longitudinal fibres 25 run forwardly from the anchoring means 22 of the energy absorber 20, but only the longest run all the way to the tip portion 21. The remainder of the longitudinal fibres 25 stop short at defined intervals so as to form a graduated arrangement t of layers which provides the requisite taper in the wall of the energy absorber 20. This arrangement is best illustrated in Figure 6.
The fibrous matting in layers 26,27,28 comprises fibres which are omni-directional in nature and which extend along the entire length of the energy absorber 20.
In the preferred embodiment, the fibrous matting layers 26,27,28 comprises carbon fibres and the layers 25 in the core comprises glass fibres. The energy absorber 20 can be formed by hand laying the fibrous matting and the longitudinally extending fibres 25 in a mould tool and then injecting a polymer resin (e. g with vacuum assistance) into the mould tool when closed. Epoxy or polyvinyl resins can be used.
The configuration of the fibres in the energy absorber 20 give the energy absorber 20 material properties which vary along its length. At the tip portion 21 of the energy absorber 20, the presence of the omni-directional fibre matting dominates the material characteristics as can be best seen in Figure 4. Conversely, the omni-directional fibrous matting has a lesser influence on the characteristics of the material in the anchoring means 22 of the energy absorber 20, as can be best seen in Figure 5. This distribution of fibres is significant in terms of the way in which the energy absorber 20 performs.
The energy absorber 20 is designed to crush in a controlled manner upon impact. During an impact, the wall of the energy absorber 20 gradually disintegrates from its tip portion 21 progressing towards its root portion 22 as the resin matrix of the wall detaches from the fibres 25,26,27, 28 it
encases. The energy absorber 20 is designed such chat the material of each energy absorber 20 starts to disintegrate well before energy absorber 20 buckle under the applied forces, even when the applied forces do not act longitudinally along the energy absorber 20 but apply bending moments to it.
The tapering cross-sectional area of the cavity of the energy absorber 20 and the tapering wall thickness 6 help the energy absorber 20 to resist bending.
The energy absorber 20 is designed so that the static strength of the energy absorber 20 increases towards the root 22, typically from 200 MPa near the tip 21 of the energy absorber 20 to 270 MPa near the root 22 (due to the varying material properties along the energy absorber 20 as a result of the fibre reinforcement configuration).
When the energy absorber 20 is crushed in an impact the dynamic strength of the material (i. e. the strength of that part of the material being crushed/disintegrated) is considerably less than the static strength. The dynamic strength also varies along the energy absorber 20, typically from 80 MPa at the tip 21 to 40 MPa at the root 22. This is due to the varying material characteristics along the energy absorber 20 which results from the distribution of fibres 25,26,27,28.
It is important to have decreasing dynamic material crush strength towards the root 22 in order to achieve a fairly constant crush force along the length of the energy absorber 20. The crush force is the product of the crush resistance and the
cross-sectional area of the material. Since the cross-sectional area of the wall increases towards the root 22, the crush resistance rr. ust be decreased in order to ensure a reasonably consistent crush force.
A second embodiment of energy absorber 30 according to the present invention is shown in Figure 7. The energy absorber 30 tapers in the same way as the energy absorber 20, and has a wall thickness which increases towards the anchoring means 32 which is attached to the anchoring means 11. However, whilst the energy absorber 20 is formed as a single integer the energy absorber 30 is formed from two component parts 30A and 30B which have flanges (e. g. 33) and which are joined together by adhesive along the flanges. The fibres in the energy absorber 30 are laid out in the same fashion as those described for energy absorber 20. The energy absorber 30 functions in the same way as the energy absorber 20, but the energy absorber 30 is easier to manufacture.
A third embodiment of energy absorber 40 according to the present invention is shown in Figure 8. In this embodiment, the energy absorber 40 comprises effectively two energy absorbers 30 joined together. The energy absorber 40 is formed of two matching parts 40A and 40B. The parts 40A and 40B have flanges (e. g. 43,44,45) which can abut each other and which are joined together by an adhesive. When the two parts 40A and 40B are adhered together, they define two parallel identical hollow cross-sectional tapering portions 46,47.
Each portion 46,47 has a cross-section and a wall
thickness which increases towards the anchoring means 42 thereof, in the same manner as the energy absorbers 20 and 30. The fibres in each portion 46, 47 are laid out in the same fashion as those described in the energy absorbers 20 and 30. The energy absorber 40 will operate during an impact in the same way as the energy absorber 20 and 30, and will operate as a pair of parallel spaced apart energy absorbers 30.
A further embodiment of the energy absorber 50 according to the present invention is shown in Figure 9. The energy absorber 50 comprises a corrugated sheet equivalent to one half (e. g. 40B) of the energy absorber 40. Attached to flanges 53, 54,55 the energy absorber 50 is a flat sheet 58.
The flat sheet 58 is attached by an adhesive. The flat sheet 58 and the corrugated sheet define two hollow tapering cavities 56,57. The cross- sectional areas of these cavities 56,57 taper linearly along the length of the energy absorber 50 from areas of greatest cross-section at the root portion 52 to areas of smallest cross-section at the tip portion 51. The wall thickness of the corrugated sheet will increase linearly towards the anchoring means 52 of the energy absorber 50.
During a impact, the material of the corrugated sheet will disintegrate as in the energy absorbers 20,30 and 40. However, the flat sheet 58 will not disintegrate, but will pee away from the corrugated sheet. The peeling will be facilitated by a suitable choice of adhesive bonding between the flat sheet 58 and the corrugated sheet.
The flat sheet 58 of the energy absorber 50, up until peeling away, acts as a stabilising panel and helps the corrugated sheet resist torsional loads.
The flat sheet 58 could form a panel of a static structure. The flat sheet 58 will typically be a glass fibre panel. The flat sheet 58 could itself be corrugated, with corrugations smaller than those of the corrugated panel. The corrugations of the flat sheet 58 would prevent cracks propagating throughout the adhesive layer between the sheet 58 and the corrugated sheet on impact.
Whilst the above cross-sections of the cavities in the energy absorbers 20,30,40,50 are either square or rectangular, the cross-sections could be of any convenient polygonal shape and could be curved in nature. For example, the energy absorbers 20,30,40 could have cavities of circular sections and energy absorber 50 a cavity of semi-circular section.
In addition, whilst the above energy absorbers 20,30,40,50 have been described as having cavities of closed cross-section, and this is advantageous for torsional rigidity, an energy absorber could be formed from a corrugated sheet with a groove or grooves open to one side, provided that the cross-sectional area (s) of the groove (s) taper (s) in accordance with the present invention and the wall thickness (es) of the corrugated sheet also taper (s).
The front tips 21,31,41,51 of the energy absorbers 20,30,40,50 could be flanged to assist the attachment of the front tips 21,31,41,51 to a
bumper (not shown).
The energy absorbers 20,30,40,50 have anchoring means to attach them to a static structure or the ground. This could be by the use of a mount 60. For example, the walls of the energy absorbers 20,30,40,50 could be secured to the mount 11 by slotting the root ends 22,32,42,52 of the walls into matching sockets in mounts comprising cast uprights. Alternatively, the energy absorbers 20, 30,40,50 could comprise apertures in walls thereof in their root ends 22,32,42,52 through which anchoring means in the form of pins (not shown) are inserted and extend into stationary structures or the ground.
A suitable arrangement of anchoring means is illustrated in Figure 10. As shown, one end of a mount 60 has a socket 61 and receives the root portion 52 of the wall of the energy absorber 50, and a second connection end 62 of the mount 60 may be either attached to a support member or be secured to the ground. The mount 60 may be formed integrally with a support member and receive the root portion 52 or alternatively could be formed separately of a support member and secured to the support member during installation of the energy absorber 50. The mount 60 could of course be cast or manufactured by other suitable processes.
The mount 60 is manufactured such that the profile of the socket 61 corresponds to the profile of the root portions 52, and is sized to hold the root portions 52 securely therein. The anchoring means may also comprise securing pins or screws (not
shown) to hold the root portion 52 in the mount 60, and thus the sizing of the socket 51 would not be so critical. In addition, bonding agents such as concrete, glue, or any other such adhesive substance may be used to hold the anchoring means 52 securely in the socket 61.
Although a mount 60 may conveniently be used as an intermediary to anchor an energy absorber e. g.
50, an energy absorber e. g. 50 may be secured directly by anchoring means to the ground or a stationary structure. Thus, the root portion 52 may comprise holes through which anchoring means in the form of pins may be inserted to secure the energy absorber to the stationary structure or the ground.
In a simple installation method a cavity will be made, in a stationary structure or the ground, suitable for receiving, e. g. the root portion 52 of the energy absorber 50. The root portion 52 will then be placed in this cavity. Anchoring means in the form of a bonding substance will then be provided between the anchoring means 52 and the walls of the cavity to secure the anchoring means 52 in the cavity. The bonding substance may be concrete, glue, or any other such adhesive substance. The cavity in a stationary structure may be an existing part of the stationary structure, formed during casting or other manufacturing process.
When the mount 60 is used, the installation method will be to secure e. g. the root portion 52 of the energy absorber 50 into the cavity 61 of the mount 60 and to mount the connection end 62 of the
mount 60 to the stationary structure or to the ground. This may be done in any order. The method may also comprise the step of proving a bonding agent between the mount and the stationary structure or the ground. Again, the bonding substance may be concrete, glue, or any other such adhesive substance.
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