CUREECaltech Woodframe Project
Element 1  Testing & Analysis
Task 1.5.1 – Development of a Seismic Analysis Software for Woodframe Construction
PI: Andre Filiatrault (University at Buffalo, SUNY  Formerly of UCSD)
Main Objectives
The main objective of Task 1.5.1 is to develop a specialized computer platform for the nonlinear seismic analysis of woodframe buildings.
Methodology
Task 1.5.1 incorporates the following two main parts, namely:
 Part 1: Development of a computer program for the Cyclic Analysis of SHEar Walls (CASHEW)
A simple numerical model to predict the loaddisplacement response and energy dissipation characteristics of wood shear walls under general quasistatic cyclic loading has been developed. In this model the shear wall is comprised of 3 structural components: rigid framing members, linear elastic sheathing panels and nonlinear sheathingtoframing connectors. The hysteretic model for the sheathingtoframing connector takes account of pinching behavior and strength and stiffness degradation under cyclic loading. A robust displacement control solution strategy is utilized to predict the wall response under general cyclic loading protocols.
The shear wall model has been incorporated into the computer program CASHEW: Cyclic Analysis of SHEar Walls. The predictive capabilities of this program have compared with monotonic and cyclic tests of fullscale wood shear walls. It has been shown that this model can accurately predict the loaddisplacement response and energy dissipation characteristic of wood shear wall under general cyclic loading.
 Part 2: Interfacing CASHEW Model with a Threedimensional Nonlinear Seismic Analysis Model
The CASHEW model will be used in conjunction with a threedimensional nonlinear seismic analysis model. A pancake model that simulates the threedimensional seismic response of a woodframe construction through a degenerated twodimensional planar analysis is being used. In this approach, each shear wall is modeled as a nonlinear shear element that adds only one degree of freedom to the problem (inplane wall behavior).
More Information
• CUREE Report : W08: CASHEW  A Computer Program For The Cyclic Analysis of Wood Shear Walls
• CUREE Report : W21: SAWS  Seismic Analysis of Woodframe Structures
