Abstract: Provided is an energy absorber for use in an opening of a wall of a building, the opening defined by a perimeter surface, the wall supporting a closure substantially filling the opening, the closure having respective edges which are substantially parallel to the perimeter surface of the opening. The energy absorber having a planar wall connecting portion, a planar closure connecting portion and a plastically deformable deforming surface therebetween. The connecting portions being substantially parallel to one another and, the deforming surface adapted to absorb, by plastic deformation, a force applied to the closure.

Abstract: An elevated platform system includes a base support structure and a plurality of fiber reinforced polymer composite panels. The base support structure includes pilings secured to a ground surface and attachment cradles coupled to the pilings. The attachment cradles are in electrical continuity with the ground surface. The fiber reinforced polymer composite panels include a panel body portion, fibrous material surrounding the panel body portion, a non-conductive matrix forming at least a portion of an outer-most layer of the fiber reinforced polymer composite panel, and an electrically-conductive layer at least partially embedded in the non-conductive matrix. The fiber reinforced polymer composite panels are coupled to the attachment cradles, such that the electrically-conductive layer of the fiber reinforced polymer composite panel is in electrical continuity with the ground surface.

Abstract: A wind turbine lattice tower structure includes a plurality of structural members connected together to define an open lattice tower, with the structural members including vertical leg members and diagonal braces extending between the vertical leg members. Pairs of the diagonal braces form cross braces having an intersection point therebetween. A damping bolt connection assembly is provides at the intersection point of the cross braces and is configured to attach the cross braces together at the intersection point while providing for relative movement of each individual cross brace along a defined longitudinal section of the other respective cross brace.

Abstract: A house constructed from finished product components and a method for constructing such house are disclosed. The components of the house such as the finished product main frame, the finished product enclosed wall, the finished product floor cover plate, the finished product top cover plate and the finished product stair are finished product industrially constructed in different manufactories, and then transported to the constructing location respectively, and then assembled at the base of the house, so as to form a house constructed from finished product components. By using finished product components, the construction of the house has high efficiency, good quality, less material consumption and shorter construction period. Furthermore, comparing with traditional site operation, constructing house from finished product components is more environment-friendly.

Abstract: An earthquake-resistant strengthening structure for building column structures, includes: a plurality of strengthening plates which are made of fiber sheet, are coupled by a concavo-convex structure in a vertical direction and are coupled by a sliding coupler in a horizontal direction; and mortar which strengthens a coupling between the strengthening plates and adheres the strengthening plates to an earthquake-resistant object. The earthquake-resistant strengthening structure is light, can be easily coupled or assembled, and provides a large binding force and tensile force by structural engagement between pieces of the strengthening plates and fusion of bonding materials. In addition, since the strengthening plates are made of glass fiber or carbon fiber, it is possible to provide an optimal earthquake-resistant strengthening structure having high durability, flexibility and strength with no corrosion.

Abstract: A passive structural system includes a structural element which may be subjected to energy which gives rise to vibration in the element. At least one bi-stable sub-structure is coupled to the element. Each bi-stable sub-structure has two stable equilibrium states between which the sub-structure can physically transition when subjected to a sufficient amount of energy which gives rise to vibration in the element, with each bi-stable sub-structure arranged to dissipate at least a portion of the energy and thereby damp the vibration in the structural element when it transitions from one equilibrium state to the other. The passive structural system may also be intentionally mistuned such that when subjected to energy which gives rise to vibration, the vibration energy is substantially confined to localized regions within the system. The bi-stable structures are then located in the localized regions and arranged to dissipate the localized vibration energy.

Abstract: The invention is an energy absorbing system for safeguarding structures from disruptive forces, which may be implemented into structures or devices to provide protection from seismic motion, blasts or other disruptive forces, due to the system's displacement and damping characteristics. The system's performance can be better molded analytically to predict performance of the structure under earthquake and wind motions, for example. By utilizing cost effective materials and a simple design, the present invention provides a more efficient cost-effective system for absorbing unwanted energy, for example, a base isolation system.

Abstract: For uncoupling a building structure from the ground a sliding pendulum bearing is suitable for the protection of building structures in the case of movements of the ground, due to earthquakes for example, or as an alternative for conventional deformation bearings. The bearing has a first sliding face with a first concave sliding face and a sliding shoe, which is in sliding contact with the first sliding face of the first sliding plate. A low friction material of a low-friction plastic is entrapped in the sliding shoe which has elastoplastic equilibrium properties. In particular as a low friction material a ultra high molecular weight polyethylene (UHMWPE) or polytetrafluoroethylene (PTFE) is utilized. After a displacement entailed by an external force the sliding shoe returns of its own accord into a stable equilibrium position.

Abstract: A shock suppressor has a first base, a second base and a connecting device. The second base is parallel to the first base. The connecting device is slidably mounted between the first base and second base to connect the first and second bases and has a universal connector. The first base abuts against the connecting device in a curved contact surface to provide a first sliding mechanism in multiple directions. The second base abuts against the connecting device to provide a second sliding mechanism in a unidirection.

Abstract: A structural framework that includes a column, a beam, a brace beam coupled at an angle to the column and the beam, and a gusset plate to connect the brace beam with the column and the beam. The framework also includes a shear plate with horizontally slotted holes to couple to the column to the beam. The structural framework may also include double framing angles or a flex plate coupled to the gusset plate and to the beam via spacer plates to provide for a semi-rigid connection.

Abstract: A building includes a connection between an engineered wood load bearing element of the building such as a column, beam, or load bearing panel, and another load bearing element or a foundation of the building. At least one tendon ties the load bearing elements or the load bearing element and the foundation together. One or more energy dissipaters, replaceably connected between the load bearing element and/or the foundation, absorb energy when a loading event causes relative movement of the connection. The engineered wood element may be a laminated veneer lumber element, a parallel strand lumber element, or a glue laminated timber element, for example. Typically all of the load bearing elements of the building will be engineered wood elements. The building may be single or multi-storey. The building system enables lightweight low cost buildings, with energy dissipaters which may be replaced after extreme loading. The building may be prefabricated.

Abstract: The present invention discloses a grouted tubular energy-dissipation unit comprising an inner tube and an outer tube. The inner tube is coaxially inserted into the outer tube defining a gap within a lapping portion of the tubes for receiving expansive cement grout. After solidified, the expansive cement grout forms an expansive ring. A prestress produced by the expansive cement grout increases the friction between the expansive ring and the tubes. In service, the present invention can transfer the axial force via the friction between the tubes and the expansive cement grout. In case of earthquake, the sliding friction between the tubes and the expansive cement grout can absorb energy. The present invention does not require high precise in manufacturing and constructing, saves steel and has low cost. It is only need to replace the grouted tubular energy-dissipation unit when the present invention is damaged in earthquake, which is very convenient.

Abstract: A method of installing distribution systems such as needed piping, ductwork, electrical wiring, and other systems in a new construction having a structural ceiling and floor, comprises the steps of: providing a frame module of main and cross frame members; assembling the modules on site directly below the final placement position; installing ductwork, piping, electrical wiring, and other distribution systems in the modules; fabricating and attaching upper wall portions to the modules; lifting modules with attached upper wall portions towards the structural ceiling; attaching support columns to the structural ceiling and floor; and mounting the modules onto the support columns, such that the support columns support the modules.

Abstract: A protection cell having an upper wall and a lower wall spaced with respect to each other through a plurality of side walls integrally connected to each other, to form an open box-like container with an entrance opening. The container defines inside a shelter space arranged to accommodate a user. In particular, the container is produced as a single block that reproduces the open box-like container. The anti-seismic cell has a movable wall portion mounted slidingly on the box-like container, by means of a sliding cooperating element, in particular a plane sliding board that slidingly engages between at least two slide paths, which are arranged at opposite sides with respect to each other. The plane sliding boards allows movable wall portion to move from an open configuration to a closed configuration, where the movable wall portion blocks the opening defining the protection cell.

Abstract: It is intended to provide a vibration control apparatus that can be installed in a small pace and can be produced at low cost, as well as a wind turbine generator equipped with the vibration control apparatus and a vibration control method. The vibration control apparatus 7 includes a first vibration system 10 of inverted-pendulum type, second vibration systems 20 of inverted-pendulum type which are provided on both sides of the first vibration system 10, a restraining unit 30 which restrains a first weight 11 of the first vibration system 10 and a second weight 21 of the second vibration system 20 and a damper which damps vibration of the first weight 11 and the second weight 21. The vibration control apparatus 7 is installed on an upper floor 8a of a plurality of floors 8.

Abstract: A moveable and demountable wall panel system for defining an office space with a plurality of wall panels disposable in a substantially upright manner between a floor and a ceiling each having respectively a series of uppermost and lowermost deviations. The system includes at least one prefabricated frameless panel, the top edge of each panel being provided with a ceiling track configured for being removably insertable into a corresponding ceiling rail. The system also includes a bottom floor channel associated with each corresponding panel and being configured for operatively resting against the floor opposite to the ceiling rail. The system also includes first and second height adjustment assemblies associated with each panel and insertable into a corresponding bottom floor channel.

Abstract: A dual-core self-centering brace apparatus is mounted to a building, and includes a first core member, at least one second core member, an outer sleeve disposed around the first and second core members, two inner abutment plates abutting respectively against two ends of the first core member, two outer abutment plates abutting respectively against two ends of the second core member, a plurality of tensioning members, and an energy-dissipating unit for retarding relative movement of the first core member and the outer sleeve. When subjected to an external force, the length of each of the tensioning elements is increased by an elongation amount, and the total length of the first core member and the outer sleeve is increased by an amount that is two times the elongation amount.

Abstract: A shock suppressor has a first base, a second base and a connecting device. The second base is parallel to the first base. The connecting device is slidably mounted between the first base and second base to connect the first and second bases and has a universal connector. The first base abuts against the connecting device in a curved contact surface to provide a first sliding mechanism in multiple directions. The second base abuts against the connecting device to provide a second sliding mechanism in a unidirection.

Abstract: A vibration damper comprises a first plate 11 that is fixed to one framework member 51, a second plate 13 that is fixed to another framework member 53, and an elastic material 15 that is filled in the interstices between the first plate 11 and the second plate 13. A first clearance W1 is formed between the another framework member 53 and a first fixing portion 21, and a second clearance W2 is formed between the first framework member 51 and a second fixing portion 29. The first plate 11 is made of a steel plate that is formed directing from the first fixing portion 21 to the second fixing portion 29, and the second plate 13 is made of a steel plate that is formed directing from the second fixing portion 29 to the first fixing portion 21. A space portion 50 constituted by the first clearance W1, the second clearance W2, the first plate 11, and the second plate 13 has a dimension which is at least sufficient for insertion of a joist 57 therein.

Abstract: An elastomeric seismic isolator bearing comprising a plurality of elastomeric layers reinforced with a plurality of fiber layers is disclosed, wherein said bearing is capable of exhibiting stable rollover when subjected to a lateral load in an unbonded application.

Abstract: A damper has two sets of first elongate members, second elongate members that are connected so that they can rotate and that connect the first elongate members to one another, and damping members which attenuate the relative movement between the first elongate members and the second elongate members. The respective first joints of each of the first members are connected to the first connection members and the second connection members so that they can rotate. The first joint of the first elongate member, the first joints of the other first elongate members, and each of the second joints are located along the common axes.

Abstract: A transportable prefabricated container house includes a main body and a house forming body, configured to be housed in the main body and drawn out of the main body at the installation site to be expanded/assembled into a house threefold the size of the main body. Assembly of the pre-assembled square “U”-shape walls sandwiched between the floor and ceiling boards includes tightly tying the ceiling supporting beams and the floor supporting beams together with shackles, and passing steel rods or pipes between the walls to render the house immune from earthquakes and hurricanes. A foundation of steel pipe bodies assists earthquake- and hurricane-resistance. Mega structures housing multitudes of container houses can be used when stacking two or more container houses is insufficient and large scale urban development is necessary, and are capable of resisting earthquakes and hurricanes due to a system of wire mesh covering.

Abstract: A seismic coupler includes two coupling members each having an end receptacle for securing to a reinforcing bar of a column of reinforced concrete; and a flexible assembly comprising a cylindrical core formed of alloy, a plurality of steel first rings put on the core, a plurality of flexible second rings put on the core in an alternating fashion with respect to the first rings, a flexible sleeve put on the first and second rings to have both ends being flush with that of the core, two cup-shaped cap members engaged each other to conceal the core, the first and second rings, and the sleeve, and two sets of a plurality of fasteners driven through the coupling members and the cup-shaped cap members into the first rings.

Abstract: A method and a device for damping relative motion between structural elements (4a, 4b, 5), and in particular for damping oscillations in a stay cable of a building or a civil engineering structure. A damping device is disclosed which provides motion damping by means of frictional engagement (1a, 1b) between friction surfaces composed of low-friction polymeric material (2a, 2b, 3a, 3b). The polymeric material preferably includes a dispersed lubricant. The use of low friction polymers results in a constant damping which is effective over a broad range of displacements and forces.

Abstract: In external renovation of a wooden framework house in which a bearing face material is used as an exterior wall base member, is capable of partly increasing the wall strength factor, thereby providing a high degree of freedom of seismic design and, furthermore, facilitating installation of an exterior material such as ceramic siding after seismic reinforcement. A reinforcement member for preventing punching shear is interposed. Between a bearing face material of a wall that is required to have a high wall strength factor by a seismic design and a nailhead of a nail for fixing the bearing face material to a structural member.

Abstract: Gusset Block Construction deals with a block that is cored from all sides. The blocks are cubes and elongated cubes with a pyramid or elongated pyramid shaped cavity on each side resulting in a block in which each of the twelve edges is central on a gusset shape extending from said edge to the central axis of the block. With the use of a second octahedron block that fits within the pyramid shaped cavities a wall that requires no fastening can be built by placing octahedrons in the top cavities of a layer of blocks and placing another layer of blocks on it. These blocks will be able to come apart at the joints during an earthquake without completely disassembling and can return to original position when the earthquake stops. They can be molded in a two piece split mold and are scaleable; tapered piers could be made.

Abstract: A civil structure block for buildings is provided. The civil structure block is composed of a mixture of a plurality of piezoelectric rods, a plurality of carbon fibers and cement material. The mixture imparts a vibration damping characteristic to the civil structure block.

Abstract: A masonry anchor and method of use for connecting first and second spaced-apart walls defining a cavity therebetween, the anchor including an anchor bracket including a slot and a pintle engaging and carried by the anchor bracket and extending outwardly from the anchor bracket and bridging a cavity between the first and second walls. The pintle includes first and second laterally spaced-apart hooks for being positioned and locked in the slot of the anchor bracket. The hooks have a nominal spacing between them that is greater than a width of the slot, and are deformable into a position wherein the hooks are spaced apart by a distance that is less than the width of the slot for allowing the hooks to be inserted into the slot, and have sufficient positional memory to return from its deformed position to its nominal spacing when manual pressure is released.

Abstract: The system described herein consists of a seismic isolator and a damping device. The system is used to isolate structures from seismic forces and further reduces transmitted forces via the seismic isolator to structure. The isolator has a spherical base fixed to ground, middle part that responds to the moving base by rotating around the centre of a small concave or convex, causing the superstructure to move upwards and downwards vertically, and a top part connected to the superstructure and the isolator middle part. The damping device consists of horizontal seismic force filter, springs, dampers and a vertical force transferor beam. Structures seismically isolated with the system herein may be protected to adequate amounts that allow minimal or no damages to the superstructures. That means continuous serviceability during and aftermath becomes achievable for the very most of the earthquakes and site characteristics combinations.

Abstract: An energy absorber for use in an opening of a wall of a building, the opening defined by a perimeter surface, the wall supporting a closure substantially filling the opening, the closure having respective edges which are substantially parallel to the perimeter surface of the opening. The energy absorber having a planar wall connecting portion, a planar closure connecting portion and a plastically deformable deforming surface therebetween. The connecting portions being substantially parallel to one another and, the deforming surface adapted to absorb, by plastic deformation, a force applied to the closure.

Abstract: A reinforcement for buildings is provided. The reinforcement is composed of a mixture of a plurality of piezoelectric rods, a plurality of carbon fibers and cement material. The mixture imparts a vibration damping characteristic in the reinforcement.

Abstract: A ductile seismic shear key construction including a concrete support, a concrete shear key supported on the concrete support, a generally vertical reinforcement bar in and extending between the concrete support and the concrete shear key and anchored in the concrete support, and an isolation key. The isolation key is in and at the base of the concrete support and adjacent the reinforcement bar. The bar can be one of the two legs of a downwardly-disposed U-shaped bar. The other leg, if present, is also in and extends between the concrete support and the shear key and is anchored in the concrete support; and a second isolation key is in the concrete support at the base thereof and adjacent the second leg. The bars can pass through through-holes in the isolation keys, particularly for an interior shear key construction. For an exterior shear key construction the bars can be disposed in notches of the isolation key.

Abstract: A large, high density foam glass tile which can be used as a facade on both exterior and interior building walls. The foam glass tile can also be used with other materials to form a panel or a composite. The present invention may be used on the critical surfaces of buildings at high risk for terrorist attacks, in combination with cement, steel or other high strength building materials. The present invention may also be used in surfaces of typical buildings. The present invention has the advantage of absorbing a substantial portion of a shock wave caused by an explosion. The present invention also has the advantage of being more resistant to earthquakes.

Abstract: A connector assembly for accurately projecting fasteners for connecting two building members together while permitting limited relative motion between the members. The assembly includes a plate having one or more longitudinal slots. The plate is secured to or a part of one of the building members. The plate is connected to the other building member by fasteners projected through breakaway washers formed in the slots. The breakaway washers each have an opening for guiding the fastener and centering the fastener on the slot. Centering the fastener on the slot prevents inadvertent clamping of the plate and the other building member together so that limited relative motion is permitted.

Abstract: The present invention relates to a compensation method for structural deformation occurring during construction of a super tall building, which includes the steps of: selecting horizontal and vertical members predicted to require compensation for horizontal and vertical deformation amounts; calculating deformation amounts based on the casting time of structural concrete for the selected horizontal or vertical members; determining compensation amounts based on the casting time of structural concrete for the selected horizontal or vertical members; calculating deformation amounts of the selected horizontal or vertical members up to and subsequent to the non-structural construction processes; determining compensation amounts by process of the selected horizontal or vertical members; and constructing the selected horizontal or vertical members by floors.

Abstract: A shock suppressor has a first base, a second base and a connecting device. The second base is parallel to the first base. The connecting device is slidably mounted between the first base and second base to connect the first and second bases and has a universal connector. The first base abuts against the connecting device in a curved contact surface to provide a first sliding mechanism in multiple directions. The second base abuts against the connecting device to provide a second sliding mechanism in a unidirection.

Abstract: A buckling restrained brace includes a deformable core contained within an outer casing. Ends of the core protrude from the casing for connection to a frame or other structure. A length of the deformable core between its ends, referred to as the gauge or yielding section, is capable of deforming during an earthquake or blast loading. The gauge section is differentially heat treated from the ends so that the gauge section has a lower yield strength than the ends. The casing provides containment of the core to prevent buckling of the core. A metal foil interface or unbonding layer is provided between the deformable core and the casing so that the deformable core does not bind to the casing. The buckling restrained brace provides significant performance improvements over prior art BRBs coupled with simplified assembly.

Abstract: A buckling restrained brace includes a deformable core contained within an outer casing. Ends of the core protrude from the casing for connection to a frame or other structure. A length of the deformable core between its ends, referred to as the gauge or yielding section, is capable of deforming during an earthquake or blast loading. The gauge section is differentially heat treated from the ends so that the gauge section has a lower yield strength than the ends. The casing provides containment of the core to prevent buckling of the core. A metal foil interface or unbonding layer is provided between the deformable core and the casing so that the deformable core does not bind to the casing. The buckling restrained brace provides significant performance improvements over prior art BRBs coupled with simplified assembly.

Abstract: The invention relates to seismic protection (anti-seismic) devices and, in particular, to seismic hysteretic dampers, used to protect the structures against severe earthquakes. These devices are installed at points where large displacements are expected due to earthquake shakings, such as between a bridge deck and bearing points of said bridge (e.g. the pier cap beam).

Abstract: An assembly for straightening a basement's wall, the basement having a floor and being covered by joists which are spaced from each other on center distances to define interstitial cavities and are arranged a perpendicular array or a parallel array, the assembly having mounting plate; joist mounting fasteners attaching the oblongated mounting plate to joists, the fasteners, upon the perpendicular joist array, positioning the mounting plate within an interstitial cavity, and the fasteners, upon the parallel array, bridging the mounting plate across an interstitial cavity; a rigid beam having upper and lower ends; a jack screw for driving the rigid beam's upper end toward the basement's wall; and an anchor bracket for resisting movement of the rigid beam's lower end away from the basement's wall.

Abstract: A fastener assembly comprises a first cylindrical member disposed within a second cylindrical member. One of the first and second cylindrical members is movable relative to the other in a first direction. The other one of the first and second cylindrical members is locked relative to the one in a second direction opposite to the first direction. A spring is operably attached to the first and second cylindrical members to urge one of the first and second cylindrical members in the first direction. A removable member is operably associated with the first and second cylindrical members to prevent one of the first and second cylindrical members from moving in the first direction prior to removing the removable member. The removable member is configured to be pulled out to allow one of the first and second cylindrical members to move in the first direction.

Abstract: This functional system for a cement mortar panel (102, 135, 160, 196, 216) with prestressed biaxial reinforcement (136, 161) consists concretely of a system contributing to the physical and formal and to the handling and use in conditions of maximum safety and efficiency of a panel (102, 135, 160, 196, 216) of the type prefabricated with cement mortar having prestressed biaxial reinforcement (136, 161) in which the cement mortar panel has embedded in the mass thereof versatile operating means (100, 157, 171, 175, 196, 217) on the panel ensemble (102, 135, 160, 196, 216) allowing for the handling and/or fixing thereof to suspension means to the structure of a building, of means controlling seismic phenomena and the settling movements of the building, means reducing damp inside the building and means reducing the infiltration of damp inside the panel.

Abstract: The invention is a system and method for automatically adjusting the resonance frequency of an energy absorbing device in response to a disruptive force. By configuring an energy absorbing device for automatic response tuning, utilizing a controller coupled to one or more sensors for processing a determination primarily based on sensing data, the natural period of an overall structure may be adjusted (i.e. increased or decreased) so that the acceleration response of the structure is decreased upon being subjected to a disruptive force, for example, high winds, a blast from an explosion, or a seismic force caused by an earthquake.

Abstract: A structure, including: at least two structural members; a joining element connected to the at least two structural members; and at least one active element within the joining element, or between the joining element and at least one of the structural members, wherein a force applied to one structural member passes at least partially through the active element and into the other structural member, the active element being configured such that the structure exhibits a prescribed load-deflection relationship when a force is applied thereto.

Abstract: A shock suppressor has a first base, a second base and a connecting device. The second base is parallel to the first base. The connecting device is slidably mounted between the first base and second base to connect the first and second bases and has a universal connector. The first base abuts against the connecting device in a curved contact surface to provide a first sliding mechanism in multiple directions. The second base abuts against the connecting device to provide a second sliding mechanism in a unidirection.

Abstract: In a panel suspended ceiling for seismic prone areas, a superstructure extends from and above the ceiling grid. The superstructure is engaged within a lateral support bar that slidably supports the superstructure, and ceiling, during a seismic event.

Abstract: The present invention provides a platform for supporting various equipment and/or structures which assists in isolating such structure from vibrations external to the platform. Generally, the platform comprises upper and lower plates, having depressions comprising a combination of linear and radial surfaces, upon which the upper plate supports the above-mentioned structure, and the lower plate contacts a surface/area upon which the platform is to rest. Between the upper and lower plates, a plurality of rigid, spherical bearings are placed within the depressions.

Abstract: The invention provides a metal joint connecting a pair of subject members relatively displaceable in one direction, a metal joint connecting a pair of subject members relatively displaceable in one direction, the metal joint comprising: multiple first attachment portions attached to one of the subject members; a second attachment portion attached to an other of the subject members; and multiple plate portions connecting between the first attachment portions and the second attachment portion to each other, wherein an attachment direction of each of the first attachment portions with respect to one subject member and an attachment direction of the second attachment portion with respect to the other subject member are set so that a surfaces of the plate portions follow a direction of the relative displacement.

Abstract: A modular building system uses a perimeter bond beam and prefabricated wall panels to form an exterior curtain wall. The wall panels are captured within, and may move vertically inside a channel formed in the bond beam. The wall panels are quickly erected by inserting an upper edge of each panel into the channel and swinging the panel onto the foundation where it is claimed in place on the foundation.

Abstract: A dual-core self-centering brace apparatus is mounted to a building, and includes a first core member, at least one second core member, an outer sleeve disposed around the first and second core members, two inner abutment plates abutting respectively against two ends of the first core member, two outer abutment plates abutting respectively against two ends of the second core member, a plurality of tensioning members, and an energy-dissipating unit for retarding relative movement of the first core member and the outer sleeve. When subjected to an external force, the length of each of the tensioning elements is increased by an elongation amount, and the total length of the first core member and the outer sleeve is increased by an amount that is two times the elongation amount.