Control structure
AssigneeJohn Damian Allen
InventorJohn Damian Allen
Life of this patent
Estimating the term…
Abstract
A control structure device for racks or buildings. The device is able to limit forces developed within itself or a structure (e.g. building or storage rack) it connects with and is seismically supportive of as it endures ground or base motion input from a seismic event. The control structure may comprise a relatively inflexible rocker frame which is pivotably connected to a foundation. Rotation of the rocker frame causes a flexural member to flexurally displace to limit force and energy in the system.
Claims41
A force limiting and energy dissipating seismic control structure comprising:
- a pivotable rocker frame having a pivot connection to a structural member;
- a yield connector comprising a resistively and resiliently deformable, elastoplastically yielding yield element, the yield connector being directly or indirectly connected between the rocker frame and the structural member wherein the yield connector comprises a first anchor for direct or indirect connection to a first end region of the yield element, and a second anchor for direct or indirect connection to a second end region of the yield element, and wherein the second anchor and second end region are configured with at least one of a free translational boundary condition or a free translational and rotational boundary condition wherein the second end region is able to translate or translate and rotate relative to a reaction surface or reaction point at the second anchor,
- whereby the yield connector is able to elastoplastically displace while maintaining a constant resistive yield force, and control and limit a dynamic response of the control structure and a mass seismically supported by the control structure, during a seismic event.
A force limiting and energy dissipating seismic control structure comprising:
- a pivotable rocker frame having a pivot connection to a structural member and being configured to be connected to a shelving, racking or building structure, the pivotable rocker frame being configured to rotate about the pivot connection as the shelving, racking or building structure moves relative to the structural member in response to a seismic event,
- a yield connector comprising a resistively and resiliently deformable, elastoplastically yielding yield element, wherein the yield connector comprises a first anchor for direct or indirect connection to the rocker frame distal from the pivot connection and a second anchor for direct or indirect connection to the structural member, and wherein one of the first or second anchors is configured with a free translational and rotational boundary condition whereby the yield element is displaced and undergoes plastic deformation at a yield zone intermediate the first anchor and second anchor during a seismic event as a result of relative oscillatory movement between the rocker frame and the structural member, and wherein the yield connector maintains a constant resistive yield force to thereby control rotation of the rocker frame about the pivot connection, the constant resistive yield force limiting and controlling the magnitude of a dynamic response force developed within the control structure during the seismic event.
A structure supported on a foundation, the structure comprising:
- a framework,
- the framework being connected to a pivotable rocker frame having a pivot connection to the foundation and being configured to rotate about the pivot connection as the framework moves relative to the structural member in response to a seismic event,
- a yield connector comprising a resistively and resiliently deformable, elastoplastically yielding yield element, and wherein the yield connector comprises a first anchor for direct or indirect connection to the rocker frame distal from the pivot connection and a second anchor for direct or indirect connection to the foundation, and wherein one of the first or second anchors is configured with a free translational and rotational boundary condition whereby the yield element is displaced and undergoes plastic deformation at a yield zone intermediate the first anchor and second anchor during a seismic event as a result of relative oscillatory movement between the rocker frame and the foundation, and wherein the yield connector maintains a constant resistive yield force to thereby control rotation of the rocker frame about the pivot connection, the constant resistive yield force limiting and controlling the magnitude of a dynamic response force developed within the framework during the seismic event.
A force limiting and energy dissipating seismic control structure comprising:
- a pivotable rocker frame pivotably connected to a structural member,
- a yield connector located between and directly or indirectly connecting rocker frame to structural member, the yield connector comprising a resistively and resiliently deformable elastoplastically yielding yield element,
- the yield element having a first region connected to a first anchor and a second end region connected to a second anchor, the first and second anchor directly or indirectly connecting to the rocker frame or structural member,
- the yield connector configured with free translational or free translational and free rotational boundary conditions, wherein the second end, edge, or boundary region of the yield element, is able to translate or translate and rotate relative to the reaction surface or reaction point at its second anchor, and without generating membrane forces within the yield element, and wherein the resultant reaction force at the reaction surface or reaction point, is able to rotate as the yield element elastoplastically displaces, and remain orthogonal to the tangent plane at the reaction surface of the yield element, and wherein the horizontal component of the resultant reaction force acts in the same direction as the horizontal translation component of the displacing end region,
- the yield element able to elastoplastically displace while maintaining a constant resistive yield force, enabling the control structure to form an elastoplastic mechanism, able to cyclically displace and plastically flow, in response to a forcing event or in response to base motion input from a seismic event, with a constant resistive yield force,
- the seismic control structure able to control and limit its dynamic response and control and limit the response acceleration and dynamic response of a mass it is seismically supportive of.
A force limiting and energy dissipating seismic control structure comprising a rocker frame which is pivotably connected to a structural base or structural member, wherein rotation of the rocker frame about the pivotal connection causes a pivotably anchored flexural yield member which is directly or indirectly connected to the rocker frame, but distal to the rocker frame pivot, to flexurally displace, wherein the yield member is configured with a (i) free translational or (ii) free translational and free rotational boundary condition to allow it to flex and yield about its minor bending axis to high elastoplastic displacements and high ductility values while maintaining a constant resistive yield force, and wherein the structure is able to dissipate energy and limit forces developed within itself or a structure it connects with and is seismically supportive of as it endures ground or base motion input from a seismic event.
Dependencies are inferred from the claim text.