Presentation on theme: "Project #4 Energy Dissipation Capacity of a Wood-frame Shear Wall CEE 3702 - Numerical Analysis."— Presentation transcript:
Project #4 Energy Dissipation Capacity of a Wood-frame Shear Wall CEE Numerical Analysis
Session Objectives Provide background on the performance of wood-frame structures subjected to earthquakes (Northridge) Provide the specifics of an experimental research program aimed at reducing damage Define the scope of the numerical analysis project
Historical Performance of Wood-Framed Structures Under Seismic Loads Properly designed and constructed structures perform “adequately” Significant secondary damage to structures following an earthquake Catastrophic failures in non-engineered or poorly constructed structures
Performance of Wood-frame Structures in the Northridge Earthquake, January 17, deaths Collapse of Hillside and Tuck-Under Parking $40 billion loss (primarily due to secondary damage)
Northridge Ground Motion
Structural vs. Nonstructural Damage Structural Systems –Beams –Columns –Slabs –Steel, Concrete, Masonry, Wood What is nonstructural damage?
Nonstructural Damage All damage that is not structural Secondary damage More costly than structural damage Includes nonphysical damage
Elevator and Door Frames
Typical Wood Shear Wall
Wood-frame Shear Walls
Anchor Bolts Quantity and Location Splitting of Bottom Plate Splitting of Posts Construction/Installation Errors
Problems in Wood Structures Cripple Walls Shear Walls Wall Openings Anchor Bolts Nonstructural Damage How do we improve these trouble areas?
Northridge Fallout City of Los Angeles Inspections Code Changes (after every EQ) Research - $6.9 million from FEMA to CUREe (California Universities for Research in Earthquake Engineering) Innovative Systems
Dynamic Test Setup Wood Shear Wall Hydraulic Actuator applying the “EQ”
Experimental Investigation Full-scale testing of conventional wood shear walls (no dampers) Full-scale testing of wood shear walls with viscoelastic dampers Compare structural properties of both
Dynamic Test Procedure
Calculation of K E and E D KEKE EDED
Numerical Analysis Project The data for two individual hysteresis loops is on the website. –1 set for a conventional wall –1 set for a diagonally damped wall Calculate the energy dissipation for each wall Determine whether or not using VE dampers as a means for increasing the energy dissipation capacity of wood-frame shear walls is feasible.
Final Project Executive Summary Problem Description Detailed Solution Methodology Results Conclusions Project Due at the beginning of class on Monday December 11th