Download presentation
Presentation is loading. Please wait.
Published byLilly Brow Modified over 10 years ago
1
Mechanics Based Modeling of the Dynamic Response of Wood Frame Building By Ricardo Foschi, Frank Lam,Helmut Prion, Carlos Ventura Henry He and Felix Yao University of B.C. CUREe-Caltech Woodframe Project Element 1 - Researchers Meeting University of California, San Diego January 2001 UBC
2
UBC Research Project: Reliability and Design of Innovative Wood Structures under Earthquake and Extreme Wind Conditions Combined analytical and experimental studies to evaluate the performance of wood frame structures Reliability procedures to consider the randomness of loading and system response Funded by Forest Renewal BC Collaborations with CUREe-Caltech Woodframe Project
3
UBC TEAM Principal researchers: R.O. Foschi, F. Lam, H. Prion, & C. Ventura F. Yao, H. Li, Y.T. Wang – Structural Analysis, Reliability H. He - Modeling and testing of simple 3D structures M. Popovski - Glulam frames D. Moses, N. Allotey, A. Schreyer - Nail & bolted connections R. Mastschuch, B. Sjoberg - Reinforced bolted connections N. Richard, P. Welzel - Openings M. Stefanescu, G. Finckenstein - Japanese Post & Beam Frames Full scale shake table testing of 2 storey buildings
4
3-D Model of Wall Systems Develop and verify 3D structural analysis model with mechanics based nail hysteresis subroutine – Model Development – Input Data – Full Scale Test Data Completed verification of static, cyclic and dynamic behaviour (2D) Completed verification of static behaviour (3D) – (PI: ROF, FL – HH)
5
Wind Load Lateral Load Vertical Load Double-side Panels Frame Nails Insulation Structural Model Light-frame building structure Sandwich diaphragm type components with optional insulation layer Wide range of material properties Multiple load inputs Load/displacement control
6
Structural Model Element types o Panel - 4-node elastic orthotropic plate element o Frame - 3D elastic beam element o Nail - nonlinear spring element in x, y, z directions Substructuring used in local-global transformations o Performed only in frame elements and connections to frame DOF in panel and frame elements NxNx NyNy MxMx MyMy dx dy x,u y,v z,w Rot-x Rot-y Rot-z M xy dx dy x y z Pure twistDisplacements & rotations qdxdy
7
Mechanics Based Nail Hysteresis Beam elements (nail) on nonlinear foundations (panel and frame) Basic material properties – Non-linear Stress Strain Behaviour of the steel – Non-linear Embedment Properties of the Wood Hysteresis behaviour
8
Cyclic Behaviour Mechanics based nail model was implemented into 3D program Single nail case compared to test results o Pinched and asymmetric hysteresis loops o Stiffness and strength degradations Possible issues o Solution Stability o Model Calibration o Material Properties
9
Mechanics-Based Nail Model
10
Monotonic and Cyclic Tests of 7.2 m Wall
11
Monotonic and Cyclic Tests of 2.4 m Walls 40 30 20 10 0 200100 80 6040 Wall 5 Wall 3 Wall 1 40 20 0 -20 -40 -808040 0 Monotonic Test Cyclic Test
12
Model Verification - Monotonic Case 1
13
Model Verification - Monotonic Case 2
14
Model Verification - Cyclic Case 1
15
Model Verification - Cyclic Case 2
16
Model Predictions - Cyclic Case
17
Shake Table Test set up of 2.4 wall Support frame Shake table Longitudinal actuator Vertical actuators Shear wall specimen Distribution beam Inertia masses
18
Model Verifications Shear Wall Fundamental Frequency Experimental Results (Hz) Model Predictions (Hz) Jtest 10a – 2.4x2.4 Jumbo Panel 4.54.0 Jtest 11 – 1.2x2.4 Regular Panels 3.32.9
19
Model Verifications Jtest11 Regular Panel Jtest10a Jumbo Panel TestModel Test Model Displ. (mm) 60.061.914.122.4 Accel. (g) 0.420.52 0.40
20
Model Verification - Dynamic Case 2D
21
Model Predictions - 3-D Static Response
22
Model of an Eccentric Structure
23
Specimen Details
24
Model Verification - Static Case 3D
25
3D Model Verification Vibration Frequencies Vibration ModeExperimental Results (Hz) Model Predictions (Hz) No.1 (Sway Motion E-W) 2.92.8 No.2 (Sway Motion N-S) 5.06.1 No.3 (Torsion)8.8
26
Model Verification - Dynamic Case 3D Single Component Shaking
27
Failed Shake Table Specimen
29
3D Simplified Model Test Observations Significant torsional response Single Component Shaking (~0.4g pga) – Damage initiated in the narrow wall – Adjacent long wall was also severely damaged – Significant softening after 1 st pulse Two Component Shaking (~0.26g pga) – Two side walls were severely damaged – Significant softening after 1 st pulse
30
Summary on Model Development Modeling/analytical procedures Program calibrations and verification (Dynamic case) o Study of structural parameters and performance Experimental procedures Verification of 3D finite element program Static Dynamic Reliability based design procedures o Response Surfaces Approaches
31
UBC’s Large Shake Table 20 ft by 25 ft rigid frame Low friction roller bearings 67 kip, 36 inch actuator
32
Subsystem testing Simulated weight of 2 nd floor
33
Two Storey House Test
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.