Friction dissipator for structures

Abstract

A friction dissipator to dissipate kinetic energy in a building structure, particularly in buildings and / or bridges; the friction dissipator (1) comprising a first element (2) and a second element (3) that have connecting holes and connecting slots; wherein the first element (2) and the second element (3) are in contact along a respective first and second contact surface (2d, 3d); the first element (2) and the second element (3) are connected by fastening systems (4) that engage the connecting holes and the connecting slots; wherein the first element (2) comprises a layer of granular and / or angular metallic particles (2c) fixed along its respective contact surface (2d; 3d) so that, when a relative motion occurs between the first element (2) and the second element (3), the contact surface (2d; 3d) presenting the granular or angular metallic particles (2c) rubs on the other contact surface (3d; 2d) and in this way dissipates kinetic energy.

Description

[0001] "FRICTION DISSIPATOR FOR STRUCTURES

[0002] Cross-Reference to Related Applications

[0003] This Patent Appl ication claims priority from Italian Patent Application No . 102024000006754 filed on March 26 , 2024 , the entire disclosure of which is incorporated herein by reference .

[0004] Technical Field

[0005] This invention concerns a friction dissipator for structures , in particular for connections in metal , wood or reinforced concrete structures .

[0006] Background

[0007] In general , a building comprises a structure , for example made of metal , wood or reinforced concrete . The structure , in turn, comprises columns , main beams , secondary beams , possibly braces and decks . Each element is attached in various ways , for example , but not exclusively, bolted or welded . In particular, the connection can be equipped with friction dissipators .

[0008] A known problem of the prior art is that a steel connection equipped with a friction dissipator may be damaged after earthquakes , exceptional events or due to changes in the static loads to which it is subj ected during use and thus requiring repair .

[0009] Another disadvantage of the prior art is that as a result of such damage , the steel structure may no longer exhibit the performance initially required .

[0010] Another disadvantage of the prior art is that such connections may require continuous maintenance and monitoring of the main parameters that ensure their proper functioning . These parameters are the degradation of the friction material lining the plates and the preload losses af fecting the dissipator bolts . The disadvantage is actually the degradation in strength that such connections exhibit when subj ected to load cycles resulting from use . This phenomenon can be traced back to the unstable hysteretic behaviour of the materials covering the device plates and to tension losses in the bolts connecting these plates to the connecting components .

[0011] Summary

[0012] One purpose of this invention is to provide a friction dissipator for connecting structures that is capable of limiting at least one of the drawbacks of the prior art .

[0013] According to this invention, a friction dissipator is provided according to any one of claims 1 to 14 .

[0014] With this invention, the friction dissipator makes it possible to equip the connections of the structure and obtain stable behaviour with reduced strength degradation and limited preload loss . In addition, this friction dissipator provides resilient characteristics while maintaining consistent performance over time .

[0015] Another purpose of this invention is to provide a building or bridge that reduces the drawbacks of the prior art .

[0016] According to this invention, a building or bridge is provided according to any one of claims 14 to 20 .

[0017] Thanks to this invention, the connection has reduced performance variation, making the building or bridge safer with regard to ordinary and exceptional events that occur over time .

[0018] Moreover, thanks to this invention, structural monitoring operations are not strictly necessary . In all cases , should it be decided to carry out such monitoring operations , for example in order to be in line with regulations , these monitoring operations could be less frequent compared to the monitoring operations of prior art structures .

[0019] Brief Description of the Drawings

[0020] In order to better understand this invention, a number of non-limiting embodiments thereof will now be described by way of example with reference to the attached drawings , in which :

[0021] - Figure 1 is a schematic view in cross section of a friction dissipator produced according to this invention;

[0022] - Figure 2 is a schematic, enlarged view of a detai l of the friction dissipator 1 represented in Figure 1 ;

[0023] - Figure 3 is a schematic view in cross section of another embodiment of a friction dissipator produced according to this invention;

[0024] - Figure 4 is a schematic view in cross section of another embodiment of a friction dissipator produced according to this invention;

[0025] - Figure 5 is a schematic view of a building comprising a structure and a plurality of friction dissipator produced in accordance with various embodiments of this invention;

[0026] - Figures 6a and 6b are schematic views of one o f the connections of the building structure in Figure 5 produced according to one embodiment of this invention, in particular illustrating the connection 12 shown in Figure 5 ;

[0027] - Figure 7 is a schematic view of one of the connections of a building structure in Figure 5 produced according to one embodiment of this invention, in particular illustrating the connection 16 shown in Figure 5 ;

[0028] - Figure 8 is a schematic view of one of the connections of a building structure in Figure 5 produced according to one embodiment of this invention, in particular representing the connection 11 shown in Figure 5 ;

[0029] - Figure 9 is a schematic view of one of the connections of a building structure in Figure 5 produced according to one embodiment of this invention, in particular representing the connection 18 shown in Figure 5 .

[0030] Description of Embodiments

[0031] With reference to Figure 1 , reference number 1 denotes a friction dissipator produced according to this invention . The friction dissipator 1 comprises one element 2 and another element 3 that cooperate with each other to dissipate kinetic energy, in particular seismic energy, when relative motion occurs between the first element 2 and the second element 3 .

[0032] More speci fically, the element 2 comprises a support 2a, in particular a plate or a slab or a profile or a flange .

[0033] In the following document , a "plate" is defined as an element having two prevailing dimensions with respect to a third, so this de finition also comprises slabs , sheets , and profiles .

[0034] The support 2a is preferably made of at least one material selected from a group of materials comprising metal , steel , weathering steel , and stainless steel . In particular, the support 2a can be coated, for example with zinc coating or other treatments , or uncoated .

[0035] The element 2 comprises a binder 2b that is placed on a contact surface 2d of the element 2 .

[0036] The element 2 comprises a layer of angular particles 2c that are fixed along the contact surface 2d of the element 2 , in particular along the contact surface 2d of the support 2a .

[0037] In particular, an "angular particle" is defined as a particle having at least one edge , preferably most or all of the edges , that is angular and / or not smoothed and / or not rounded .

[0038] In addition, the hardness of the layer 2c can vary in a range between the extremes 100 and 1200 HV .

[0039] The particles of the particle layer 2c are fixed to the support 2a by the binder 2b ( Figure 2 ) .

[0040] In an optional and non-limiting embodiment , the binder 2b is copper- or tin-based one and the fastening is done thermally, for example heat-welded .

[0041] With reference to Figure 2 , the particle layer 2c extends for a thickness s along a transverse direction d of the element 2 . In particular, the transverse direction d extends from the support 2a to the particle layer 2c .

[0042] These angular and / or granular particles 2c have a predefined si ze and are preferably made of stainless steel / cast iron / metal carbide .

[0043] These angular / granular particles 2c can have dif ferent granulations and varying densities . Speci fically, one of the dimensions along the transverse direction d varies within a range of 0.1 - 1.5 mm, specifically 0.1 - 1.0 mm, 0.1 - 0.8 mm, specifically equal to 0.2 mm or 0.5 mm or 0.8 mm.

[0044] In a preferred embodiment, the particles are homogeneous with each other relative to said dimension along the transverse direction d.

[0045] In a preferred embodiment, the particles 2c do not overlap each other in the particle layer 2c, as a result the thickness s of the particle layer 2c has a dimension along the transverse direction d varying within a range of 0.1 - 1.5 mm, in particular 0.1 - 1.0 mm, 0.1 - 0.8 mm, in particular equal to 0.2 mm or 0.5 mm or 0.8 mm.

[0046] In one embodiment, the thickness s and the transverse dimension along the direction d of each particle essentially coincide .

[0047] The density varies from 1 to 100 particles per cm2, specifically from 5 to 50 particles per cm2.

[0048] In a preferred but non-limiting embodiment of this invention, the angular particles 2c are randomly distributed, in particular they are irregularly distributed.

[0049] With reference to Figures 1 and 2, the element 3 comprises a support 3a that is selected from a group comprising: a plate, a slab, a profile, and a flange.

[0050] The support 3a is preferably made of a material selected from a group of materials comprising metal, steel, weathering steel, stainless steel with a coated surface, for example with zinc plating or another treatment or uncoated.

[0051] The support 3a has at least one slot 3b to which the element 2 is connected by means of fastening means 4, preferably a high-strength bolt, especially comprising a screw 4a and a nut 4b. In an optional and non-limiting embodiment of this invention, the fastening system 4 , preferably the bolt , is made at least partially of a shape memory material , in particular a shape memory alloy with a surface coated, for example , with zinc plating or another treatment or uncoated . This bolt is able to regain its original shape when subj ected to appropriate heat treatment after undergoing plastic deformation . This allows the bolt to be restored after any plastic deformation following strong stresses . Thanks to this invention, the friction dissipator as described in this invention can thus simply be restored by heat treatment instead of replacement i f it is slightly damaged after earthquakes , exceptional events or due to changes in the static loads it is subj ected to during use .

[0052] In an optional and non-limiting embodiment of this invention, the fastening system 4 may comprise a fastening system with sensors that measures the preload and / or clamping force of the fastening medium, for example by comprising a sensor housed on a fastening body of the fastening system . Thanks to this invention, it is possible to monitor the variation of preload losses and / or the forces acting on these fastening means , for example to perform structural monitoring and increase the resilience of a structure . The sensor comprises a power supply, a measuring unit configured to measure the clamping and / or preload force , and a communication unit to send the data measured by the measuring unit ; in particular, the communication unit is wireless or wired, but preferably wireless .

[0053] The slot 3b enables the support 3a to move along the extension of the slot . As mentioned above , the first element 2 and the second element 3 are in contact with each other along their respective contact surfaces 2d and 3d; as a result , the angular / granular particle layer 2c is in contact with the contact surface 3d of the element 3 , interpenetrating said contact surface 3d . When, in use , relative sliding occurs between the first element 2 and the second element 3 , there is plastic deformation of the element 3 and part of the material covering it is removed . This mechanism determines the coupling between the element 2 and the element 3 , which results in high-performance friction behaviour .

[0054] In general , the invention appl ies to a friction dissipator 1 comprising a slotted support 3a connected using a bolt 4 to the element 2 so that the slotted support 3a is in contact with the angular particle layer 2c . Alternatively or together, the angular particles may also be macro rough and / or granular . In other words , the angular particles 2c covering the element 2 must be in contact with the element 3 . The first element 2 and the second element 3 have a variable thickness to be defined according to design requirements .

[0055] In all the embodiments , the element 2 is a single , continuous body and the surface 2c has a certain uni form average density along its extension in its two main directions .

[0056] In another embodiment not illustrated, the support 2a has a slot in place to the slot present in the element 3 or in addition to the slot present in the element 3 .

[0057] In another embodiment not illustrated, the friction dissipator comprises an angular particle layer made in the same way as the angular particle layer 2c but deposited on the support 3a instead of or in addition to the particle layer 2c on the support 2a .

[0058] In general , the invention requires at least one granular layer deposited on either or both supports 2a or 3a .

[0059] In general , the invention appl ies to a friction dissipator 1 comprising any number of elements 2 . At least one element 3 is arranged between two elements 2 . The elements 2 and 3 are then stacked on top of each other and fastened together using one or more fastening means , preferably high-strength bolts .

[0060] In a non-limiting embodiment of this invention, for example as illustrated in Figure 3 , the friction di ssipator 1 comprises two elements 2 , a slotted element 3 and two outer elements 5 .

[0061] The elements 2 of the embodiment in Figure 3 are equal to the elements 2 of the embodiments in Figures 1 to 2 , each of which has a contact surface 2d covered by a particle layer 2c along one of its sides , preferably one of the two larger sides .

[0062] The slotted element 3 has two contact surfaces 3d on its two preferably opposite and larger sides .

[0063] In particular, the two elements 2 are connected by means of fastening means 4 to the element 3 , in particular a slotted slab or plate , and to two outer elements 5 , in particular outer slabs or plates 5 .

[0064] The outer elements 5 are preferably slabs or plates made of metal , steel , weathering steel , stainless steel with a coated surface , for example with a zinc coating or other treatments or uncoated . In other words , the slotted element 3 is connected to two elements 2 whose task is to dissipate kinetic energy when the element 3 moves with respect to the elements 2 , in particular by means of the granular particle layer 2c, in particular unfinished or angular particles , which are in contact with the two contact surfaces 3d of the element 3 .

[0065] With reference to Figure 4 , another non-limiting embodiment of this invention is illustrated, wherein the friction dissipator 1 comprises , in addition to the friction dissipator 1 components of Figures 1 , 2 and 3 , a first plurality of washers 6 , in particular flat washers and / or a second plurality of washers 7 , in particular conical washers .

[0066] In particular, the first and / or second plurality of washers 6 and 7 are arranged between the bolts 4 and elements 2 and 3 . In particular, i f both types of washers 6 and 7 are inserted, the friction dissipator 1 is configured so that the concavity of the conical washers faces the plate 3 . In a preferred embodiment , the conical washers can be precrushed and assembled, in particular several overlapping conical washers with the same concavity or overlapping washers with opposite concavities . The minimum number of conical washers is one .

[0067] The use of a combined system of flat washers and conical washers limits a known drawback of the prior art in that it reduces preload losses in the bolts and, as a result , stabilises the behaviour of the friction dissipator in all the embodiments listed here .

[0068] Each of the friction dissipators 1 illustrated in each of Figures 1 to 5 can be used in a building as part of connections between the main structural elements . The building according to this invention may also have only one of the connections illustrated below and does not have to have all the connections illustrated below .

[0069] With reference to Figure 5 , a building is denoted with reference number 8 . In particular, the building 8 comprises a foundation 13 and structure 8a attached to the foundation 13 .

[0070] In particular, the structure 8a can be a metal or wooden structure or a concrete structure .

[0071] The structure 8a comprises at least one deck 14 , preferably a plurality of decks ; and at least one plurality of vertical structural elements 9 that are supported and attached to the foundation 13 with a connection 12 .

[0072] In a non-limiting embodiment , the vertical structural elements 9 can be metal columns , for example steel columns .

[0073] In a non-limiting embodiment , each deck 14 comprises at least one hori zontal structural element , in particular a plurality of hori zontal structural elements 10 , for example preferably metal or steel beams .

[0074] In a non-limiting embodiment of this invention, the building 8 comprises at least one connection 12 , wherein each connection 12 connects at least one point of the foundation 13 to at least one vertical structural element 9 . Wherein this connection 12 comprises at least one of the friction dissipators 1 illustrated above . As mentioned, one , several or all the connections 12 with the friction dissipator 1 may also not be included in the building 8 and be replaced by any connection .

[0075] Thanks to said connection 12 comprising one or more friction dissipators 1 , the loads acting on the vertical structural elements 9 are discharged in a dampened way from the dissipator 1 onto the foundation 13 without causing damage to the structure 8a when stressed by exceptional actions , for example seismic movements .

[0076] In an optional and non-limiting embodiment of this invention, the at least one hori zontal structural element 10 is supported and fastened to the vertical structural elements

[0077] 9 by means of a connection 11 comprising the friction dissipator 1 as will be illustrated in Figure 8 capable of trans ferring loads from the horizontal structural elements

[0078] 10 to the vertical structural elements 9 exhibiting adequate flexural rigidity and rotational capacity without inducing damage to the other nodal elements . As mentioned, one , several or all the connections 11 comprising the friction dissipator 1 may also not be present in the building 8 and be replaced by normal connections .

[0079] Thanks to said connection 11 comprising one or more friction dissipators 1 , the movements between the hori zontal structural elements 10 and the vertical structural elements 9 are dampened without causing damage , or with minimal damage , to the structure 8a when stressed by exceptional actions , for example seismic movements .

[0080] In addition, in an optional and non-limiting embodiment of this invention, said structure 8a may also comprise diagonal structural elements 15 , connected to the vertical structural elements 9 and hori zontal structural elements 10 . Along its axis , the diagonal structural element 15 has a connection 16 comprising the friction dissipator 1 that can be seen in detail in Figure 7 . In addition, said diagonal structural elements 15 may be connected to the vertical elements 9 via a connection 18 . As mentioned, one , several or all of the diagonal structural elements 15 and connections 16 or 18 may also not be present in said structure 8a and in the building 8 .

[0081] Thanks to said connection 16 or 18 comprising one or more friction dissipators 1 , the movements of the diagonal structural elements 15 are dampened without causing damage , or with minimal damage , to the structure 8a when stressed by exceptional actions , for example seismic movements .

[0082] With reference to Figures 6a and 6b, an embodiment of this invention is shown in which the connection 12 along the vertical structural element 9 near the foundation 13 of the building 8 is illustrated . The vertical structural element 9 is preferably a metal column with a double-T profile and comprises two flanges 9a and a core 9b extending between the two flanges 9a . In this non-limiting embodiment of this invention, the vertical structural element 9 , near the foundation 13 , is divided into two parts , an upper part and a lower part . These parts are connected to each other along the flanges 9a by the connection 12 , which comprises the friction dissipator 1 , in particular the one described in Figure 3 . Speci fically, in this embodiment depicted in Figure 6a, the flanges 9a of the upper part of the column 9 define the element 3 of the friction dissipator 1 and, along the flanges 9a, there is the slot 3b of the friction dissipator 1 . The elements 2 of the friction dissipator 1 , in particular the plates coated with the angular particle layer 2 c are in contact with the flange 9a defining the element 3 and are connected, in particular by means of high-strength bolts 4 , to the plates 5 via the slots 3b . In another embodiment depicted in Figure 6b, the core 9b of the upper part of the column 9 defines the element 3 of the friction dissipator 1 and along the core 9b there is the slot 3b of the friction dissipator 1 . The elements 2 of the friction dissipator 1 , in particular the plates coated with the angular particle layer 2c are in contact with the core 9b defining the element 3 and are connected, in particular by means of high-strength bolts 4 , to the plates 5 via the slots 3b .

[0083] In a preferred embodiment , the flanges 9a in Figure 6a or the core 9b in Figure 6b are connected by means of high- strength bolts 4 to the plates 5 via flat washers 6 or with flat washers 6 and conical washers 7 , which are not visible in these figures . In this case , the conical washers 7 , i f any, are arranged with their concavity facing the plates 5 and the elements 2 are positioned so that the layer 2c of the element 2 contacts the plate 5 .

[0084] In one embodiment, the connection 12 comprises both the friction dissipators 1 connected to the flanges 9a as shown in Figure 6a and the friction dissipator 1 connected to the core 9b as shown in Figure 6b .

[0085] In a non-limiting embodiment of this invention illustrated in Figure 7 , the friction dissipator 1 is used in creating the connection 16 of the inclined structural elements 15 . This connection occurs along the axis of the structural element 15 and may represent the j oining of two parts of it or the j oining of two structural elements 15 .

[0086] The inclined structural element 15 is preferably a metal bracing, in particular with a UPN / box-shaped / L-shaped profile . Figure 7 shows a bracing made from 2 coupled UPNs 15 , the connection of which occurs along the axis of the element and j oins two parts of it . In particular, the metal profiles 15 have two flanges 15a between which there extends a core 15b . The cores 15b of the two structural elements 15 represent plates 5 of the friction dissipator 1 created according to Figure 3 . Between them is the friction dissipator 1 in which, in this case , the elements 2 are defined by two plates and the element 3 is defined by a slotted central plate . The plates 15b, first elements 2 and second elements 3 are fastened using the fastening means 4 .

[0087] In an alternative , non-illustrated embodiment of this invention, the angular particle layer 2c of the friction dissipator 1 is created along a face of the core 15b that is directly in contact with the element 3 of the friction dissipator 1 or is created along the face of the element 3 that is directly in contact with a face of the core 15b .

[0088] In this embodiment , as a non-limiting option, the fastening means , that is the bolts 4 , can be fitted with flat washers 6 or flat washers 6 and conical washers 7 arranged according to the embodiments described above . The connection 17 shown in Figure 7 is not binding for the proper use of this invention in the embodiment described and is , therefore , not detailed .

[0089] For the purposes of implementing the connection 16 of the inclined structural element 15 , this embodiment does not limit this invention .

[0090] In a preferred but non-limiting embodiment of this invention illustrated in Figure 8 , the friction dissipator 1 of the embodiment illustrated in Figure 3 is used in the creation of the connection 11 between the hori zontal structural elements 10 and the vertical structural elements 9 of the building 8 ( Figure 5 ) . Reference number 11 denotes the connection of the hori zontal structural element 10 , preferably a metal beam with a double-T profile , to the vertical structural element 9 , preferably a metal column .

[0091] The metal beam 10 comprises an upper flange 10a, a lower flange 10b and a core 10c extending between the two upper 10a and lower flanges 10b . In this embodiment , the lower flange 10b of the beam 10 defines or comprises the element 3 of the friction dissipator 1 , namely a slotted plate , of the friction dissipator 1 of Figure 3 . The elements 2 of the friction dissipator 1 are arranged between said flange 10b, which defines or comprises the element 3 , and the plates 5 described in Figures 4 and 5 , which, in said embodiment , are defined or comprised by the elements 18 that permit the connection of the lower flange 10b of the beam 10 to the vertical structural element 9 . The plates 2 , 3 and 18 are connected by means of high-strength bolts 4 possibly equipped with flat washers 6 or flat washers 6 and conical washers 7 as shown in Figure 5 . The connections 19 and 20 are illustrated by way of example only and do not l imit this invention .

[0092] In a non-limiting embodiment of this invention illustrated in Figure 9 , the friction dissipator 1 is used in the creation of the connection 18 between the inclined structural elements 15 to the vertical structural elements 9 or to the horizontal structural elements 10 ( instead of the vertical structural elements 9 shown in Figure 9 ) .

[0093] More speci fically, the connection 18 comprises a friction dissipator 1 as shown in Figure 3 , wherein the element 3 is either connected to or is integral with or is defined by or is a portion of the vertical structural element 9 ( or the hori zontal structural element 10 ) .

[0094] The cores 15b of the two structural elements 15 represent plates 5 of the friction dissipator 1 created according to Figure 3 . Between them is the friction dissipator 1 in which, in this case , the elements 2 are defined by two plates . The plates 15b, the elements 2 and the element 3 are fastened using the fastening means 4 .

[0095] In an alternative , non-illustrated embodiment of this invention, the angular particle layer 2c of the friction dissipator 1 is created along a face of the core 15b that is directly in contact with the element 3 of the friction dissipator 1 or is created along the face of the element 3 that is directly in contact with a face of the core 15b .

[0096] In this embodiment , as a non-limiting option, the fastening means , that is the bolts 4 , can be fitted with flat washers 6 or flat washers 6 and conical washers 7 arranged according to the embodiments described above . The connection 18 shown in Figure 7 is not binding for the proper use of this invention in the embodiment described and is , therefore , not detailed .

[0097] There are numerous advantages to the invention described above , including :

[0098] The use of the element 2 comprising a surface layer 2d of high- friction granular particles 2c in the friction dissipator 1 signi ficantly reduces the degradation of strength, thus making it possible to produce a friction dissipator whose performance remains virtually unchanged after an exceptional event ; the particular finish of the plate 2 , and in particular the granular particles 2c applied to the surface 2d, cause uni form damage to the element 3 with which it is in contact , resulting in a much greater dissipating capacity; the dissipator, in its embodiments , also reduces the preload losses of preload initially applied in the fastening means , that is the high-strength bolts , reducing the need for maintenance and monitoring of the devices themselves .

[0099] At the end of an exceptional event , the friction dissipator 1 can be returned to its initial position without degradation .

[0100] In addition, the friction diss ipator 1 is heat- resistant and the dissipation characteristics remain largely unchanged within a temperature range of up to 1000 ° C . In particular, the friction dissipator retains its characteristics unchanged in the event of a fire .

[0101] In addition, the friction dissipator 1 ensures limited corrosion and oxidation, so it can be installed in special environments such as , for example , in buildings near the sea or in buildings located in particularly humid areas .

[0102] Furthermore , a friction dissipator made according to this invention can be used not only for the structures explicitly described above , but al so for any other civil or military structure such as , for example , bridges or structures for roads or railways or buildings , and for residential , manufacturing, transport uses .

[0103] The above-described invention also applies to a bridge comprising a structure 8a, preferably a metal one , which in turn comprises at least two structural elements selected from the group of structural elements including : vertical structural elements 9 , at least one deck 14 , at least one foundation 13 , at least one diagonal structural element 15 ; and wherein the bridge comprises at least one connection illustrated above for the structure 8a of the building 8 . Finally, it is clear that the embodiments described and illustrated herein are examples of embodiments and that the scope of protection of the patent application is not limited to the embodiments illustrated above but is defined in the attached claims .

Claims

CLAIMS1. A friction dissipator to dissipate kinetic energy in a building structure, particularly in buildings and / or bridges; the friction dissipator (1) comprising a first element (2) and a second element (3) ; wherein one of the first element (2) and the second element (3) , preferably the first element, has connecting holes, in particular circular holes or slots, and the other among the second element (3) and the first element (2) , preferably the second element, has connecting slots; wherein the first element (2) and the second element (3) are facing and in contact with each other along a respective first and second contact surfaces (2d, 3d) ; the first element (2) and the second element (3) are connected by fastening system (4) that engage the connection holes and the connecting slots; wherein one of the first and second elements (2; 3) , preferably the first element (2) , comprises a layer of angular particles (2c) , preferably metallic, fixed along its respective contact surface (2d; 3d) so that, when a relative motion occurs between the first element (2) and the second element (3) , the contact surface (2d; 3d) presenting the angular particles (2c) of one between the first and second elements ( 2, 3) rubs on the contact surface (3d; 2d) of the other among the first and second elements (2, 3) and in this way dissipates kinetic energy.

2. The dissipator according to claim 1, wherein the first element (2) comprises a first support (2a) , in particular a plate or slab or profile or flange or sheet; and the layer of angular particles (2c) , in particular metallic; preferably the layer of angular particles (2c) comprising grains preferably metallic; the dissipatorcomprising a binder (2b) with which this layer of angular particles (2c) is attached, preferably heat-welded, to the support (2a) along the first contact surface (2d) .

3. The dissipator of any of the foregoing claims, wherein the second element (3) comprises a second support (3a) , in particular a plate or slab or profile or flange or sheet; the second support (3a) has the connecting slots (3b) ; in particular, the second support comprises one of the following materials: metal, steel, weathering steel, stainless steel with a coated surface, for example with a zinc coating or other treatments, or uncoated.

4. The dissipator according to any of the above claims, wherein the angular particle layer (2c) comprises a plurality of stainless steel and / or cast iron and / or metal carbide particle grains.

5. The dissipator according to any of the above claims, in which the layer of granular and / or angular particles (2c) includes a plurality of particle grains, preferably metallic, of varying sizes.

6. The dissipator according to any of the above claims, wherein the angular particle layer (2c) comprises a plurality of particle grains with equal or variable dimensions and wherein such uniform or variable size is in the range of 0.1 mm to 1.5 mm, in particular 0.1 - 1.0 mm, 0.1 - 0.8 mm, in particular equal to 0.2 mm or 0.5 mm or 0.8 mm.

7. The dissipator according to any of the above claims, in which the angular particle layer (2c) comprises a plurality of grains of particles having a density that is within the density range of 1 to 100 particles per cm2, inparticular ranging from 5 to 50 particles per cm2; and / or the hardness ranges from 100 to 1200 HV.

8. The dissipator according to any of the above claims, comprising a further first element (2) comprising a respective further layer of granular and / or angular particles (2c) ; and wherein the second element (3) is interposed between the first element (2) and the further first element (2) , and has a further second contact surface (3d) preferably opposite the second contact surface (3d) ; wherein each further contact surface (2d) of the further first element (2) is in contact with the further second contact surface (3d) of the second element (3) .

9. The dissipator of claim 8, comprising an outer plate (5) and preferably a further outer plate (5) , wherein the outer plate (5) is in contact with the first element (2) along a surface opposite the first contact surface (2d) and preferably the further outer plate (5) is in contact with the further first element (2) along a surface opposite the further first contact surface (2d) ; preferably the first outer plate is placed between at least one end of the fastening system and the first element (2) ; preferably the further first outer plate (5) is placed between the other end of the fastening system and the further first element (2) .

10. The dissipator according to any of the above claims, wherein the friction dissipator (1) comprises a first plurality of washers (6) , in particular flat washers, and / or a second plurality of washers (7) , in particular conical washers; in which the first and / or second plurality of washers (6, 7) are interposed between the fastening system(4) and the first and / or second elements (2, 3) in order to reduce the preload losses of the fastening system (4) and to stabilize the behaviour of the friction dissipator (1) .

11. The dissipator according to any of the above claims, wherein the second element (3) or the first element (2) has at least one slot (3b) to which the first element (2) or the second element (3) is connected by a respective fastening system (4) , preferably a high-strength bolt which in particular includes a screw and a nut.

12. The dissipator according to any of the above claims, wherein the fastening system (4) comprises a shape memory alloy and is preferably configured to be restored by heat treatment after any plastic deformation caused by stress .

13. The dissipator according to any one of the above claims, wherein the fastening system (4) comprises a fastener assembly and a sensor to measure the clamping and / or preload force and is configured to send data relating to the current clamping force and / or preload; in particular, the sensor is housed in the fastening system and includes a measuring unit configured to measure the clamping and / or preload force and a communication unit to send the data detected by the measuring unit.

14. A building or bridge comprising a structure, preferably a metal structure, which in turn includes at least two structural elements selected from the group of structural elements: vertical structural elements (9) , at least one deck (14) , at least one foundation (13) , at least one structural diagonal element (15) ; wherein the building (8) or bridge includes at least one connection (11, 16, 18, 12)connecting at least the two structural elements and wherein that connection (11, 16, 18, 12) includes at least one friction dissipator (1) made in accordance with one of claims 1 to 13.

15. The building or bridge of claim 14, wherein one of at least two structural elements is at least one deck (14) and the other of at least two structural elements is a vertical structural element (9) ; the at least one deck (14) comprises a plurality of horizontal structural elements (10) , preferably metal beams e.g. steel beams, wherein at least one connection (11) connects a portion of at least one vertical structural element (9) with a portion of at least one horizontal structural element (10) .

16. The building or bridge of claim 15, wherein a flange (10a) of the structural horizontal element (10) defines or includes or is integral to the second element (3) of the friction dissipator (1) of the connection (11) .

17. The building or bridge of any one of claims 14 to 16, wherein one of the structural elements is a vertical structural element (9) ; wherein at least one connection (12) connects two portions, in particular an upper and a lower portion of the vertical structure element (9) .

18. The building or bridge of claim 17, wherein a flange (9a) and / or core (9b) of the vertical structural element (9) defines and / or includes and / or is integral to the second element (3) .

19. The building or bridge of at least any one of claims 14 to 18, wherein at least two structural elements are two structural diagonal elements (15) ; wherein at least one connection (16) connects a portion of one of the twostructural diagonal elements (14) with a portion of the other of the two structural diagonal elements (15) .

20. The building or bridge of claim 19, in which the friction dissipator is made in accordance with claim 9; in which each of the structural diagonal elements (15) has a core (15b) that comprises and / or defines and / or is integral to one of the outer plates of the friction dissipator (1) .

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