Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 1 Group Project #2 Energy Dissipation Capacity of a Woodframe Shear Wall

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 2 Session Objectives Provide background on the performance of woodframe structures subjected to earthquakes (Northridge) Provide the specifics of an experimental research program aimed at reducing damage Define the scope of Group Project #2

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 3 Historical Performance of Woodframe 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

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 4 Performance of Wood-frame Structures in the Northridge Earthquake, January 17, deaths Collapsed structures $20 billion loss Primarily due to secondary damage

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 5

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 6 Structural vs. Nonstructural Damage Structural Systems –Beams –Columns –Slabs –Steel, Concrete, Masonry, Wood What is nonstructural damage?

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 7 Nonstructural Damage All damage that is not structural Secondary damage More costly than structural damage Includes nonphysical damage

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 8 Window Frames

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 9 Nonstructural Damage

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 10 Woodframe Shear Walls

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 11 Typical Shear Wall Test Specimen

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 12 Woodframe Shear Walls

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 13 Northridge Fallout – Making Improvements 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

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 14 Scope and Objective of the Experimental Research Program Investigate and evaluate methods for increasing the energy dissipation capacity of wood- framed shear walls using viscoelastic dampers.

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 15 Viscoelastic Dampers Viscoelastic dampers manufactured by 3M Prevalent in Steel and Concrete Structures Never been applied to woodframe structures

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 16 Diagonal Damping Scheme

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 17 Dynamic Test Setup Wood Shear Wall Hydraulic Actuator applying the “EQ”

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 18 Experimental Investigation Full-scale testing of conventional wood shear walls (no dampers) Full-scale testing of wood shear walls with viscoelastic dampers Compare structural performance

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 19 Northridge Ground Motion

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 20 Dynamic Test Procedure

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 21 Typical Results

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis Definition of Stiffness, K E and Energy Dissipation Capacity, E D KEKE EDED

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 23 Project #2 The data for two individual hysteresis loops are 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.

Villanova University Dept. of Civil & Environmental Engineering CEE 3704 Statistical and Numerical Analysis 24 Group Project #2 Executive Summary Problem Description Detailed Solution Methodology –Justification for your solution technique –Step by step procedure for calculating E D (with sketches as necessary) Results Conclusions Project Due at the beginning of class on Thursday, December 11th