Element 1 - Testing & Analysis
Task 1.5.2 Demand Aspects
PI: Helmut Krawinkler (Stanford University)
A comprehensive seismic design philosophy including capacity design concepts is currently lacking for woodframe construction. In particular, there is no consensus on what the primary energy-dissipating elements in a woodframe structure should be to insure an expected performance level. In order to develop a rational performance-based seismic design procedure for woodframe construction, deformation and force demands must be established for various earthquake intensities. Task 1.5.2 will address the seismic demands on the main sub-components of woodframe construction and their interaction in a structural system.
The main objective of Task 1.5.2 is to provide information on the seismic demands (deformations and forces) on the main components of the lateral-load resisting systems of woodframe construction. This information is to be used to evaluate the adequacy of current code procedures and to provide the background for a rational performance-based seismic design procedure.
The demand evaluation will be performed through nonlinear time history analysis, using representative SDOF and MDOF systems and the sets of ground motions employed in the wood testing protocol project (Task 1.3.2). The structural systems to be analyzed are 2-dimensional and are made up of truss elements connected by spring elements that permit a description of vertical translation between shear wall panels, and of slip and axial deformation in hold-downs and straps. The properties of the diagonals are tuned to represent horizontal force-deformation behavior of shear-wall panels of different strength and stiffness.