EP4688407A1

EP4688407A1 - Dissipative structural connection system for fiber-reinforced composites materials and their dissipative structural connection complex

Info

Publication number: EP4688407A1
Application number: EP24722077.5A
Authority: EP
Inventors: Francesco ASCIONE; Mario D'ANIELLO; Luciano FEO; Luigi GRANATA; Raffaele LANDOLFO
Original assignee: Universita degli Studi di Salerno
Current assignee: Universita degli Studi di Salerno
Priority date: 2023-03-27
Filing date: 2024-03-27
Publication date: 2026-02-11
Also published as: WO2024201296A1

Abstract

System (1), and related dissipative structural connection system, configured to be connected to at least a first beam (T) in fibre-reinforced polymer matrix material and to at least a second beam (C) in fibre-reinforced matrix material polymeric, said connection system (1) comprising a nodal core (2), at least one dissipative element (3) coupled to said nodal core (2), at least one first coupling element (4) coupled to said at least one dissipative element ( 3) and configured to be coupled, by means of adhesive, to said at least one first beam (T), and at least one second coupling element (5) coupled to said nodal core (2) and configured to be coupled, by means of adhesive, to said at least one second beam (C), such that the longitudinal axis of said at least one first beam (T), when coupled to said at least one first coupling element (4), is orthogonal with respect to the longitudinal axis of said at least a second beam (C), when coupled to said at least one second coupling element (5), wherein said at least one dissipative element (3) is configured to dissipate a determined amount of energy when said at least one first beam (T) is coupled to said at least one first coupling element (4), said at least one second beam (C) is coupled to said at least one second coupling element (5), and said at least one first beam (T) is subjected to a flexural load.

Description

DISSIPATIVE STRUCTURAL CONNECTION SYSTEM FOR FIBER-REINFORCED COMPOSITES MATERIALS AND THEIR DISSIPATIVE STRUCTURAL CONNECTION COMPLEX

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The present invention concerns a dissipative structural connection system, in particular to connect at least one beam made of fibre-reinforced material with a polymer matrix to at least one column made of fibre-reinforced material with a polymer matrix, which allows, in a simple, reliable, efficient, versatile and economical way, to coupling one or more beams to one or more columns, appropriately dissipating the energy transmitted to the connection system itself, simplifying any restoration operations and at the same time reducing costs.

Furthermore, the present invention concerns a dissipative structural connection system, i.e. a dissipative structure connection system connected to at least one beam and one column, both of fibre-reinforced polymer matrix material.

In the remainder of this description, reference will mainly be made to a dissipative structural connection system used to connect at least one beam made of fibre-reinforced material to at least one pultruded column of the same material. However, it must be kept in mind that the connection system according to the invention can be used to couple beams and pultruded columns in fibre-reinforced composite material (hereinafter FRP) and, more generally, fibre-reinforced beams and/or columns, always remaining within the scope of protection, as defined by the attached claims.

Again, in the present description no distinction will be made between beams and columns, but generic reference will be made to the connection between beams, meaning by beam an elementary load-bearing structure, in which the longitudinal dimensions prevail over the transversal ones.

It is known that FRP beams present, compared to beams made of traditional building materials, high resistance in relation to a low specific weight, excellent resistance to aggressive agents, and high simplicity and speed of installation. Furthermore, as they do not require maintenance, they are optimal for the development of resistant and sustainable structures.

Pultrusion is currently the most used method for the industrial production of constant section FRP beams.

It is well known in the technical literature that one of the main problems related to the use of FRP beams is the realization of their connection.

Indeed, unlike connection systems between elements, in particular beams, in traditional building materials (for example, reinforced concrete and/or steel), where the node is overresistant compared to the flexural resistance of the connected elements, in connection systems between elements, in particular FRP beams, the node is, however, under-resistant compared to the flexural resistance of the connected FRP beams. In particular, based on the experimental data currently available in the literature, it is estimated that the resistance of the node is equal to approximately 30% of the flexural resistance of the FRP beams connected to it.

With particular reference to a beam-column connection, which as stated above can be generalized as a beam-beam connection, two main technologies for its realization are well known in civil engineering: bolting and gluing. It is often technical practice to combine the two bolting and gluing technologies in order to increase the resistance of the connection.

The connection systems between elements, in particular beams, with an open section in FRP made by bolting are subject to breakages localized mostly around the holes made for the passage of the bolts.

In order to increase the rigidity of such connection systems, multiple and laborious solutions have been developed in the prior art.

In some connection systems of the prior art, angles and partitions have been used in order to increase the rigidity of the connection system itself.

In other connection systems of the prior art, the use of a so-called universal connector has been instead provided for the purpose of stiffening the connection and therefore increasing its resistance.

Furthermore, further connection systems of the prior art use a monolithic element in which the beams and columns are stacked, connecting them to it by gluing, whereby the confinement of the node favors an increase in its resistance.

The prior art connection systems described above are characterized by a good level of flexural strength and stiffness. In the field of civil engineering, these connection systems are inspired by those typically used for connecting steel beams. Thanks to its isotropic nature together with an elastic-plastic trend of the stress-strain diagram, steel is an appropriate material for creating ductile connections, i.e. capable of dissipating energy. The latter is a fundamental requirement for the creation of main load-bearing connections.

An example of a prior art dissipative structural connection system for metal beams, achieved by bolting, is described in document CN217840299U.

However, these connection systems, when used for the connection of elements, in particular beams, in FRP , have the disadvantage of having to pierce the structural profile of the element, in particular of the beam, thus interrupting the continuity of the fibers and creating of areas of fragility, with particular reference to recrowding.

Furthermore, the presence of the hole creates areas of weakness with respect to aggressive agents such as, for example, atmospheric agents, determining a decay of the mechanical properties over time and at the same time reducing their durability, which is one of the typical characteristics of the elements, in particular of the beams, in FRP.

It has been experimentally observed that the gluing technique for creating beam-column connections between FRP elements has greater flexural resistance and greater stiffness compared to prior art connection systems made by bolting. This is due to the absence of holes, therefore guaranteeing the continuity of the fibers and at the same time a more uniform diffusion of tensions in the adhesive layer.

The best performing prior art connection systems made by gluing include a box-like element that acts as a column and two C-shaped profiles which, using adhesive, are connected to the column creating what in technical jargon is called a composite beam.

The stiffness and flexural resistance of connection systems using gluing are generally superior to those of similar connection systems made using bolting.

At the same time, however, the glued connections present a linear-elastic behavior until failure characterized by a brittle failure not suited to the need to create ductile connections capable of dissipating energy.

Furthermore, these connection systems are difficult to repair and involve high repair costs in terms of labor.

Connection systems for FRP beams made through the combination of bolting and gluing are known.

Some connection systems of the prior art, created through the combination of bolting and gluing, provide two steel socket joints for coupling with beams with a closed profile, in particular box-shaped ones. The two socket joints are then connected to each other via bolts. These connection systems are characterized by high ductility due to the presence of steel joints.

Furthermore, another connection system of the prior art provides a steel sleeve connected, by gluing, to a first FRP beam. The sleeve is in turn connected, by bolting, to a second steel beam using angle brackets.

A further connection system of the prior art is created using box profiles which act as a column, while the beam, of a composite type, is obtained from two C-shaped profiles glued and bolted to the sides of the first beam. This further connection system is characterized by an almost plastic behavior, presenting multi-stage failures: first failures related to the adhesive, subsequent failures related to the FRP beams and, finally, failures related to the bolts.

Typically, in the field of civil engineering, connection systems created through the combination of bolting and gluing are characterized by satisfactory elastic-plastic behavior, although the problems of non-repairability and/or presence of holes in the FRP material remain.

The aim of the present invention is, therefore, to connect at least a first beam in fibre- reinforced material with a polymer matrix to at least one column, or to a second beam, in fibre- reinforced material with a polymer matrix, in a simple, reliable, efficient, versatile and economical, guaranteeing the continuity of the fibers and therefore the maintenance of the high anti-corrosion properties of the material, and at the same time dissipating the energy transmitted to the connection system when one of the connected beams is subjected to a bending load, simplifying any restoration operations and while reducing costs.

The specific object of the present invention is a dissipative structural connection system configured to be connected to at least a first beam made of fibre-reinforced polymeric matrix material and to at least a second beam made of fibre-reinforced polymeric matrix material, in which said connection system comprises:

- a nodal core,

- at least one dissipative element coupled to said nodal core,

- at least one first coupling element coupled to said at least one dissipative element and configured to be coupled, by means of adhesive, to said at least one first beam, and

- at least one second coupling element coupled to said nodal core and configured to be coupled, via adhesive, to said at least one second beam, such that the longitudinal axis of said at least one first beam, when coupled to said at least one first element coupling element, is orthogonal to the longitudinal axis of said at least one second beam, when coupled to said at least one second coupling element, wherein said at least one dissipative element is configured to dissipate a specific amount of energy when said at least one first beam is coupled to said at least one first coupling element, said at least one second beam is coupled to said at least one second coupling element, and said at least one first beam is subjected to a bending load.

According to another aspect of the invention, said at least one first coupling element may comprise a coupling plate, wherein said coupling plate comprises a first main face and a second main face, parallel to the midplane of said coupling plate, in wherein said first main face and/or said second main face are configured to be coupled, via adhesive, to said at least one first beam, and wherein said coupling plate is arranged such that said mean plane of said coupling plate is parallel to the longitudinal axis of said at least one second beam, when coupled to said at least one second coupling element.

According to a further aspect of the invention, said at least one first coupling element can comprise a first flange configured to couple, via bolts, said coupling plate to said at least one dissipative element.

According to an additional aspect of the invention, said nodal core may comprise a body, a bottom plate and a top plate, wherein said body extends between said bottom plate and said top plate, and wherein the mean plane of said bottom plate and the mean plane of said top plate are parallel to each other and perpendicular to the mean plane of said coupling plate.

According to another aspect of the invention, said body can have an IPE profile or a boxshaped profile.

According to a further aspect of the invention, said at least one second coupling element can comprise a box-shaped element, in which said box-shaped element has an internal surface, and in which at least a portion of said internal surface is configured to be coupled, via adhesive, said at least a second beam.

According to an additional aspect of the invention, said at least one second coupling element can comprise a second flange configured to couple, via bolts, said box-shaped element to said nodal core.

According to another aspect of the invention, said second flange can be configured to couple, via bolts, said box-shaped element to said bottom plate or to said top plate.

According to a further aspect of the invention, said at least one dissipative element can be coupled to said nodal core, and/or to said at least one first coupling element, via bolts.

According to an additional aspect of the invention, said at least one dissipative element can have a C-shaped section and can include a first free end, a second free end, parallel to said first free end, and a dissipative plate which extends perpendicularly between said first free end and said second free end.

According to another aspect of the invention, said first free end and said second free end can be coupled, by means of bolts, to said bottom plate and said top plate respectively. According to a further aspect of the invention, said dissipative plate (31) can be coupled, by means of bolts, to said first flange.

According to an additional aspect of the invention, the connection system may comprise a sensor, optionally selected from the group comprising or consisting of a strain gauge, an optical sensor, an inductive sensor, a capacitive sensor, and a resistive sensor, wherein said sensor it is configured to detect a deformation of said at least one dissipative element and send an electrical signal to an electronic control unit.

The specific object of the present invention is also a dissipative structural connection assembly comprising a dissipative structural connection system as previously described, a first beam in fibre-reinforced material with a polymer matrix and a second beam in fibre-reinforced material with a polymer matrix, in which said first beam is coupled, by means of a first adhesive, to said at least one first coupling element and said second beam is coupled, by means of a second adhesive, preferably identical to said first adhesive, to said at least one second coupling element, and wherein said at least one element dissipative is under-resistant compared to the coupling between said first beam and said at least one first coupling element , and/or to the coupling between said second beam and said at least one second coupling element.

According to another aspect of the invention, said first beam can comprise a first halfbeam and a second half-beam, and wherein said first half-beam and said second half-beam are respectively coupled, by means of adhesive, to said first face main parts and to said second main face of said coupling plate.

The advantages offered by the dissipative structural connection systemO, and the related dissipative structural connection assembly, according to the invention are evident.

First of all, it allows to obtain a beam-beam connection, in particular a beam-column connection, with high stiffness and flexural resistance, and with an elastic-plastic behavior suitable for use in the field of civil engineering.

Furthermore, by not having to make holes in the FRP beams, the continuity of the fibers contained within the beams themselves is guaranteed. This door has greater resistance of the connection compared to aggressive agents such as, for example, atmospheric agents, determining the maintenance of mechanical properties over time and, at the same time, increasing durability.

Furthermore, the absence of holes in the FRP beams increases the resistance of the connection against failures due to recrowding. Furthermore, by including deformable elements, the connection obtained through the structural connection system according to the invention, and the related structural connection assembly, is ductile, i.e. capable of dissipating energy.

Furthermore, by concentrating any deformations in ductile elements made of metal, in particular steel or aluminium, connected to each other by means of bolts, the connection can be restored easily, quickly and at low cost.

The present invention will now be described, by way of illustration, but not by way of limitation, according to its preferred embodiments, with particular reference to the figures of the attached drawings, in which:

Figure 1 shows an exploded perspective view of the dissipative structural connection system according to the invention and a first exploded perspective view of the related dissipative structural connection assembly in a first embodiment comprising two beams;

Figure 2 shows a perspective view of the dissipative structural connection system according to the invention and an exploded perspective view of the related dissipative structural connection assembly in a second embodiment comprising four beams;

Figure 3 shows a perspective view of the dissipative structural connection system according to the invention and an exploded perspective view of the related dissipative structural connection assembly in a third embodiment comprising four beams; And

Figure 4 shows a perspective view of the dissipative structural connection system according to the invention and an exploded perspective view of the related dissipative structural connection assembly in a fourth embodiment comprising six beams; And

Figure 5 shows four load-displacement diagrams relating to the dissipative structural connection system according to the invention.

In the Figures identical reference numbers will be used for similar elements.

In the following description, directional terminology, such as "right", "left", "front", "back", "base", "top", "top", "bottom", "side", etc., is used with reference to the figures in the attached drawings. Since components and/or elements and/or embodiments of the present invention can be positioned and/or operated in various different orientations, the directional terminology is used purely for exemplary and non-limiting purposes.

With reference to Figure 1, one can observe a first embodiment of a dissipative structural connection assembly according to the invention comprising a first beam T in fibre-reinforced polymeric matrix material which acts as a beam, a second beam C in fibre-reinforced matrix material polymer which acts as a column, and a dissipative structural connection system 1, again according to the invention, in a preferred embodiment.

The connection system 1 connects, or rather couples, the first beam T to the second beam C, in such a way that the first beam T is perpendicular to the second beam C.

Again with reference to Figure 1, the connection system 1 includes a nodal core 2, a first coupling element 4 configured to be coupled to the first beam T and to the nodal core 2, and a second coupling element 5 configured to be coupled to the second beam C and to the nodal core 2. In particular, the first coupling element 4 is coupled to the nodal core 2 by means of a dissipative element 3. In this way, the first beam T and the second beam C are connected to each other by means of the coupling chain first coupling element 4, dissipative element 3, nodal core 2 and second coupling element 5.

The first coupling element 4, the dissipative element 3, the nodal core 2 and the second coupling element 5 are each preferably made of metal, and even more preferably of steel or aluminium. Including deformable elements, the connection system 1, and the related structural connection assembly, is ductile, i.e. capable of dissipating energy.

Furthermore, the coupling between the first coupling element 4 and the dissipative element 3, the coupling the dissipative element 3 and the nodal core 2, and the coupling between the nodal core 2 and the second coupling element 5 are, each, preferably made by bolting. By concentrating any deformations in ductile elements made of metal, in particular steel or aluminium, connected to each other by bolting, the connection system 1 can be restored easily, quickly and at low cost.

Again with reference to Figure 1, the first coupling element 4 is configured to be coupled to the first beam T by means of adhesive.

In particular, the first coupling element 4 includes a coupling plate 41. The coupling plate 41 has a first main face and a second main face, parallel to the mean plane of the coupling plate 41. The first main face and/or the second main face are configured to be coupled, by means of adhesive, to the first beam T. The coupling plate 41 is arranged in such a way that the first and second faces are parallel to the main forces to which the first beam T will be subjected, in use. In this way, the bending resistance offered by the coupling plate 41 is maximum. Typically, the first beam T acts as an actual beam, and the main forces to which it will be subjected are flexural forces, while the second beam C typically acts as a column, and the main forces to which it will be subjected are compressive forces. Furthermore, the first beam T is perpendicular to the second beam C, therefore the main bending forces to which the first beam T will be subjected are parallel to the longitudinal axis of the second beam C. Therefore, the coupling plate 41 is arranged in such a way that the first and second faces are parallel to the longitudinal axis of the second beam C.

Preferably, the first beam T, included in the dissipative structural connection assembly shown in Figure 1, can comprise a first half-beam T1 and/or a second half-beam T2. The first half-beam T1 and/or the second half-beam T2 can be respectively coupled, by means of adhesive, to the first main face and to the second main face of the coupling plate 41. It is clear, however, how beams with geometries can be used different, configured so that a portion of their surface can be coupled by means of adhesive with at least a portion of the surface of the first coupling element 4, without thereby departing from the scope of protection, as defined by the attached claims.

The coupling by gluing between the first T beam and the first coupling element 4 allows avoiding the creation of holes in the first T beam itself, thus guaranteeing the continuity of the fibers inside it, greater resistance to aggressive agents, and greater resistance to the recrowding process.

Furthermore, the gluing coupling, as already mentioned, presents a linear-elastic behavior until failure.

The first coupling element 4 comprises, again, a first flange 42. The flange 42 is configured to couple, by means of bolts, the coupling plate 41 to the dissipative element 3. The flange 42 can in turn be a plate welded to the plate coupling plate 41 or can be achieved by bending a portion of the coupling plate 41 itself.

The dissipative element 3 has a C-shaped section and includes a first free end 32, a second free end 33, parallel to the first free end 32, and a dissipative plate 31 which extends perpendicularly between said first free end 32 and said second end free 33.

The first free end 32 and the second free end 33 can be coupled to the dissipative plate 31 by welding, or they can be made by bending a portion of the dissipative plate 31 itself, so as to create a C-shaped section.

However, dissipative elements 3 can be made with other shapes, for example, in the shape of a cylindrical hinge, in such a way as to be able to connect inclined, i.e. non-orthogonal, beams to each other (think, for example, of so-called truss systems) , without thereby departing from the scope of protection, as defined by the attached claims. The flange 42 is coupled by bolting to the dissipative plate 31, while the first free end 32 and the second free end 33 are coupled by bolting to the nodal core 2.

The nodal core 2 comprises, in turn, a body 21, a bottom plate 22 and a top plate 23. The bottom plate 22 and the top plate 23 are parallel, preferably with the sides parallel to each other, so to be mirrored. The body 21 extends between the bottom plate 22 and the top plate 23, and can have an IPE or box section. In the case of a box section there is the advantage of having equal stiffness in all directions. Preferably, the body 21 has a length, which coincides with the distance between the bottom plate 22 and the bottom plate 23, equal to the height of the beam T (i.e. the dimension parallel to the longitudinal axis of the second beam C).

The first free end 32 and the second free end 33 of the dissipative element 3 are coupled, respectively, at one side of the bottom plate 22 and the top plate 23, in particular by bolting.

As will be described better below, any possible deformations due to bending loads applied on the first beam T, in use, are concentrated in the dissipative element 3. In the preferred embodiment of the connection system 1 shown in Figure 1, the element dissipative 3 is coupled by bolting, both to the first coupling element 4 and to the nodal core 2. Bolting is a type of removable coupling, which allows two or more coupled elements to be separated easily and without damage. This means that, in the event of deformation of the dissipative element 3, during use, the connection system 1, or the dissipative structural connection assembly, according to the invention can be restored easily, quickly and at low cost .

Again with reference to Figure 1, the second coupling element 5 is configured to be coupled to the second beam C by means of adhesive. In particular, the second coupling element 5 includes a box-shaped element 51, for example, a cup joint. The box-shaped element 51 has a cavity, and therefore an internal surface, configured to accommodate the second beam C. The connection between the second beam C and the second coupling elements 5 occurs through the adhesion, by means of a glue, of a portion of the surface of the second beam C with the internal surface of the box-shaped element 51.

Preferably, the second beam C, included in the dissipative structural connection assembly shown in Figure 1, has a closed section, also box-shaped. It is clear, however, how beams with different geometries can be used, configured so that a portion of their surface can be coupled by means of adhesive with at least a portion of the surface of the second coupling element 5, and in particular with a portion of the internal surface of the box-shaped element 51, without thereby departing from the scope of protection, as defined by the attached claims. The coupling by gluing between the second beam C and the second coupling element 5 allows avoiding the creation of holes in the second beam C itself, thus guaranteeing the continuity of the fibers inside it, greater resistance to aggressive agents, and greater resistance to the plasticization phenomenon that occurs in mechanical unions when the load exceed a certain value.

Furthermore, the second coupling element 5 includes a second flange 52 configured to couple, by means of bolts, the box-shaped element 51 to said nodal core 2. In particular, the second flange 52 is configured to couple, by means of bolts, the box-shaped element 51 to said bottom plate 22 or to said top plate 23.

In order to concentrate the deformations within the connection system 1, the dissipative element 3 can be sized in such a way as to be under-resistant compared to the coupling, by means of gluing, between the first beam T and the first coupling element 4, and/or between the second beam C and the second coupling element 5.

In particular, the dissipative structural connection complex, in the first embodiment shown in Figure 1, comprising the dissipative structural connection system 1, the first T beam in polymer matrix fibre-reinforced material and the second C beam in matrix fibre-reinforced material polymeric.

The first beam T is coupled, by means of a first adhesive, to the first coupling element 4, for a first gluing length, where the first gluing length is the length of the portion of the first beam T and first coupling element 4 superimposed between them and coupled by means of the first adhesive.

Similarly, the second beam C is coupled, by means of a second adhesive, which can be of the same type as the first adhesive, to the second coupling element 5, for a second gluing length, where the second gluing length means the length of the portion of the second beam C and second coupling element 5 superimposed on each other and coupled by means of the second adhesive.

In this way, when a flexural load is applied, in use, to the first T beam, the dissipative element 3 will begin to deform, dissipating energy, before the connection between the first T beam and the first coupling element breaks. 4, and/or second beam C and second coupling element 5. Experimental tests were carried out on samples of the structural connection assembly according to the invention, in particular made according to the first embodiment shown in Figure 1. The results of these tests are summarized in the load-displacement diagrams in figures a, b , c and d. The load (expressed in kN) applied to the first beam T is shown on the ordinate axis, while the vertical displacement (expressed in mm) of the point of application of the load itself is shown on the abscissa axis, i.e. in correspondence with the extreme section of the first T beam.

The aforementioned diagrams highlight how the dissipative element 3 is generally underresistant compared to the couplings made through gluing, i.e. through the first adhesive and the second adhesive (whose ultimate resistance is represented by the horizontal asymptote of the diagram) and how the deformation is in it concentrated and originates from load levels lower than those of failure of these connections made through the first adhesive and the second adhesive. The load level to which the plasticization of the dissipative element 3 corresponds increases with its thickness (Tf_USe ) as well as, even if more marginally, with the distance of the bolts (dn ) used for the coupling between the dissipated element 3 and the nodal core 2. The resistance of the connections made using the first adhesive increases with the first bonding length (lb,b ). In the experiments, the coupling by means of the second adhesive, relating to the second beam C inserted into the box-shaped element 51, was not taken into account, as the second beam C will hardly be able to decouple and come out of the box-shaped element 51, taking into account the typical normal stress transmitted to the second beam itself in use.

Figure 5 shows, by way of example, the diagrams for the dissipative element 3 in the case of gluing length I t>,b equal to 150 mm (Figures 5a and 5c) and 220 mm (Figures 5b and 5d), distance between the bolts d H equal to 60 mm (Figures 5a and 5b) and 80 mm (Figures 5c and 5d), and for different values of the thickness of the dissipative element 3, in particular for T fused equal to 2, 3, 4, 5 , 8, and 10 mm.

It may be particularly advantageous to provide a sensor coupled to the connection system 1 and configured to detect a deformation of the same, in particular a deformation of the dissipative element 3. in this way, the information of a possible deformation of the dissipative element 3, detected by the sensor, could be sent, by means of cable or wireless connection, to a system for monitoring the state of the dissipative structural connection complex, and in detail of the coupling system 1.

This monitoring system, which can be, for example, a mobile device, a cloud device or a personal computer, can be used, for example, to inform or send an alarm to one or more operators.

The sensor can be, for example, a strain gauge or an optical, inductive, capacitive or resistive sensor.

Figure 2 shows a second embodiment of the dissipative structural connection assembly. In particular, the dissipative structural connection complex includes four beams, of which two first beams T which act as beams orthogonal to each other, and two second beams C which act as a bottom or lower column and a top or upper column. Consequently, the connection system 1 includes two first coupling elements 4, two dissipative elements 3, two second coupling elements 5 and a nodal core 2.

The two second beams C are coupled, by gluing, each to a respective second coupling element 5 and are arranged in a mirror image with respect to the nodal core 2, i.e. they are coaxial. In fact, the two second coupling elements 5 are respectively coupled, by bolting, to the bottom plate 22 and to the top plate 23 of the nodal core.

The two first beams T are coupled, by gluing, each to a respective first coupling element 4 and are arranged orthogonally to each other. In fact, the two first coupling elements 4 are respectively coupled, by means of bolting, to two dissipative elements 3, which in turn are coupled, by means of bolting, to two respective adjacent sides of the bottom plate 22 and the top plate 23 of the nodal core, such that the two coupling plates 41 of each first coupling element 4 are orthogonal to each other.

Figure 3 shows a third embodiment of the dissipative structural connection assembly. In particular, the dissipative structural connection complex includes, also in this case, four beams, of which two first beams T which act as beams aligned with each other, and two second beams C which act as a bottom or bottom column and column of top, or superior. Consequently, the connection system 1 also includes two first coupling elements 4, two dissipative elements 3, two second coupling elements 5 and a nodal core 2.

The only difference between the third embodiment and the second embodiment of the dissipative structural connection assembly is that the two first T beams are arranged in a mirrorlike manner with respect to the nodal core 2, i.e. they are aligned longitudinally. In fact, the two first coupling elements 4 are respectively coupled, by means of bolting, to two dissipative elements 3, which in turn are coupled, by means of bolting, to two respective opposite sides of the bottom plate 22 and the top plate 23 of the nodal core, such that the two coupling plates 41 of each first coupling element 4 are coplanar. Figure 4 shows a fourth embodiment of the dissipative structural connection assembly. In particular, the dissipative structural connection complex includes six beams, of which four first beams T which act as beams in pairs aligned with each other and orthogonal to the other two, and two second beams C which act as a bottom or lower column, and top or upper column. Consequently, the connection system 1 also includes four first coupling elements 4, four dissipative elements 3, two second coupling elements 5 and a nodal core 2.

The only difference between the fourth embodiment and the third embodiment of the dissipative structural connection assembly is that the two further first beams T are arranged, mutually in a mirror-like manner with respect to the nodal core 2, or are arranged orthogonally with respect to the other two first beams T. In fact, the four first coupling elements 4 are respectively coupled, by bolting, to four dissipative elements 3, which in turn are coupled, by bolting, to a respective side of the bottom plate 22 and of the top plate 23 of the nodal core, such that the coupling plates 41 of each first coupling element 4 are coplanar or orthogonal to each other. In the foregoing, the preferred embodiments have been described and variations of the present invention have been suggested, but it is to be understood that those skilled in the art will be able to make modifications and changes without thereby departing from the relevant scope of protection, as defined by the claims, attached.

Claims

1. Dissipative structural connection system (1) configured to be connected to at least one first beam (T) made of fibre-reinforced polymeric matrix material and to at least one second beam (C) made of fibre-reinforced polymeric matrix material, wherein said connection system (1) includes:

- a nodal core (2),

- at least one dissipative element (3) coupled to said nodal core (2),

- at least one first coupling element (4) coupled to said at least one dissipative element (3) and configured to be coupled, by means of adhesive, to said at least one first beam (T), and

- at least one second coupling element (5) coupled to said nodal core (2) and configured to be coupled, by means of adhesive, to said at least one second beam (C), so that the longitudinal axis of said at least one first beam (T), when coupled to said at least one first coupling element (4), is orthogonal with respect to the longitudinal axis of said at least one second beam (C), when coupled to said at least one second coupling element (5), wherein said at least one dissipative element (3) is configured to dissipate a determined amount of energy when said at least one first beam (T) is coupled to said at least one first coupling element (4), said at least one second beam (C) is coupled to said at least one second coupling element (5), and said at least one first beam (T) is subjected to a bending load.

2. Connection system (1) according to the preceding claim, wherein said at least one first coupling element (4) comprises a coupling plate (41), wherein said coupling plate (41) comprises a first main face and a second main face, parallel to the mean plane of said coupling plate (41), wherein said first main face and/or said second main face are configured to be coupled, by means of adhesive, to said at least one first beam (T), and wherein said coupling plate (41) is arranged so that said mean plane of said coupling plate (41) is parallel to the longitudinal axis of said at least one second beam (C), when coupled to said at least one second coupling element (5).

3. Connection system (1) according to the preceding claim, wherein said at least one first coupling element (4) comprises a first flange (42) configured to couple, by means of bolts, said coupling plate (41) to said at least one dissipative element (3).

4. Connection system (1) according to claim 2 or 3, wherein said nodal core (2) comprises a body (21), a bottom plate (22) and a top plate (23), wherein said body ( 21) extends between said bottom plate (22) and said top plate (23), and wherein the mean plane of said bottom plate (22) and the mean plane of said top plate (23) are parallel to each other and perpendicular to the mean plane of said coupling plate (41).

5. Connection system (1) according to the preceding claim, wherein said body (21) has an I PE profile or a box-shaped profile.

6. Connection system (1) according to any one of the preceding claims, wherein said at least one second coupling element (5) comprises a box-shaped element (51), wherein said boxshaped element (51) has an inner surface, and wherein at least one portion of said inner surface is configured to be coupled, by means of adhesive, to said at least one second beam (C).

7. Connection system (1) according to the preceding claim, wherein said at least one second coupling element (5) comprises a second flange (52) configured to couple, by means of bolts, said box-shaped element (51) to said nodal core (2).

8. Connection system (1) according to the preceding claim, when dependent on claim 4, wherein said second flange (52) is configured to couple, by means of bolts, said box-shaped element (51) to said bottom plate (22) or to said top plate (23).

9. Connection system (1) according to any one of the preceding claims, wherein said at least one dissipative element (3) is coupled to said nodal core (2), and/or to said at least one first coupling element (4), by means of bolts.

10. Connection system (1) according to any one of the preceding claims, wherein said at least one dissipative element (3) has a C-shaped cross-section and comprises a first free end (32), a second free end (33), parallel to said first free end (32), and a dissipative plate (31) extending perpendicularly between said first free end (32) and said second free end (33).

11. Connection system (1) according to the preceding claim, when dependent on claim 4, wherein said first free end (32) and said second free end (33) are coupled, by means of bolts, respectively to said bottom plate (22) and said top plate (23).

12. Connection system (1) according to claim 10 or 11, when dependent on claim 3, wherein said dissipative plate (31) is coupled, by means of bolts, to said first flange (42).

13. Connection system (1) according to any one of the preceding claims, comprising a sensor, optionally selected from the group comprising or consisting of a strain gauge, an optical sensor, an inductive sensor, a capacitive sensor, and a resistive sensor, wherein said sensor it is configured to detect a deformation of said at least one dissipative element (3) and to send an electric signal to an electronic control unit.

14. Dissipative structural connection assembly comprising a dissipative structural connection system (1) according to any one of the preceding claims, a first beam (T) made of fibre-reinforced polymeric matrix material and a second beam (C) made of fibre-reinforced polymeric matrix material, wherein said first beam (T) is coupled, by means of a first adhesive, to said at least one first coupling element (4) and said second beam (C) is coupled, by means of a second adhesive, preferably identical to said first adhesive, to said at least one second coupling element (5), and wherein said at least one dissipative element (3) is under-resistant with respect to the coupling between said first beam (T) and said at least one first coupling element (4), and/or to the coupling between said second beam (C) and said at least one second coupling element (5).

15. Dissipative structural connection assembly according to the preceding claim, when dependent on claim 2, wherein said first beam (T) comprises a first semi-beam (Tl) and a second semi-beam (T2), and wherein said first semi-beam (Tl) and said second semi-beam (T2) are respectively coupled, by means of adhesive, to said first main face and to said second main face of said coupling plate (41).