LATERAL RESISTANCE of TRADITIONAL JAPANESE POST-AND-BEAM FRAMES UNDER MONOTONIC and CYCLIC LOADING CONDITIONS by MARIA STEFANESC
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LATERAL RESISTANCE OF TRADITIONAL JAPANESE POST-AND-BEAM FRAMES UNDER MONOTONIC AND CYCLIC LOADING CONDITIONS by MARIA STEFANESCU B. Eng." Transilvania " University, Brasov, Romania, 1992 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in FACULTY OF GRADUATE STUDIES Department of Wood Science We accept this thesis as conforming to the required standards THE UNIVERSITY OF BRITISH COLUMBIA March, 2000 ® Maria Stefanescu, 2000 UBC Special Collections - Thesis Authorisation Form http://www.library.ubc.ca/spcoll/thesauth.html In presenting this thesis in partial fulfilment of the requirements for ah advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of The University of British Columbia Vancouver, Canada Date 1 of 1 3/27/00 8:59 AM ABSTRACT Full-scale tests were conducted on three types of traditional Japanese post-and-beam wall frames (2-Brace, 4-Brace and OSB sheathed frames) to determine the lateral loading resistance under monotonic and cyclic loading procedures. Twelve tests were conducted on 2.62 x 2.70 m frames, constructed with British Columbia Hem-fir timber and oriented strand board panels as sheathing (JIS - Japanese grade) provided by Ainsworth Lumber Ltd. Five specimens were tested monotonically using a loading rate of 0.13 mm/sec and seven specimens were tested cyclically using various loading protocols (UBC, UBC - modified and MOC). The ultimate loads measured in the monotonic tests were close to those measured in the cyclic tests but the corresponding displacements were much smaller for the cyclic tests in comparison with the monotonic tests. The experimental results showed the influence of the various cyclic loading procedures on the structural performance of the post-and-beam frames. The MOC-protocol induced a slightly lower capacity in comparison with the UBC- protocol. The 2-Brace and 4-Brace frames experienced higher initial stiffness and higher loads under lateral loading but they were relatively brittle systems. The sill failed in tension perpendicular to grain due to the fact that the nails from the metal plates used for the sill-post connection created a zone of concentrated tension perpendicular to grain stresses in the sill. In comparison with the 4-Brace frames the OSB frames experienced lower peak load but a substantially higher ductility. The results of this project suggest that the connectors used for these types of frames can be improved to obtain higher capacity and higher ductility. ii TABLE OF CONTENTS ABSTRACT ii TABLE OF CONTENTS iii LIST OF TABLES v LIST OF FIGURES vi ACKNOWLEDGEMENT x CHAPTER I - INTRODUCTION 1 1.1 OVERVIEW l 1.2 OBJECTIVES 6 CHAPTER II - BACKGROUND 8 2.1 GENERAL 8 2.2 TESTING PROCEDURES 9 2.3 HISTORICAL REVIEW 16 2.4 PROPERTY DEFINITIONS - EARTHQUAKE PERFORMANCE INDICATORS 34 CHAPTER III - SPECIMEN CONFIGURATIONS 37 3.1 POST AND BEAM FRAME CONFIGURATION 37 3.2" T" JOINT SPECIMEN CONFIGURATION 48 CHAPTER IV -EXPERIMENTAL SETTINGS AND TESTING PROCEDURES 49 4.1 POST-AND-BEAM FRAMES 49 4.2 "T" CONNECTOR 55 CHAPTER V - MONOTONIC EXPERIMENTAL RESULTS FOR POST-AND-BEAM FRAMES.58 5.1 LOAD - DISPLACEMENT CURVES 58 iii 5.2 FAILURE MODES 65 5.3 OVERALL FRAME RESPONSE 72 CHAPTER VI - CYCLIC EXPERIMENTAL RESULTS FOR POST-AND-BEAM FRAMES 76 6.1 LOAD - DISPLACEMENT CURVES 76 6.2 FAILURE MODES 81 6.3 OVERALL FRAME RESPONSE 86 CHAPTER VII - MONOTONIC EXPERIMENTAL TEST RESULTS FOR " T " CONNECTION.91 CHAPTER VIII -CONCLUSIONS AND RECOMMENDATIONS 99 8.1 CONCLUSIONS 99 8.2 RECOMMENDATIONS 102 BIBLIOGRAPHY 103 iv LIST OF TABLES TABLE 4.1 TESTING PROCEDURES 53 TABLE 5.1 MONOTONIC TEST RESULTS 72 TABLE 5.2 VERTICAL DISPLACEMENTS OF THE END STUDS AT ULTIMATE CAPACITY....74 TABLE 6.1 CYCLIC TEST RESULTS 87 TABLE 6.2 VERTICAL DISPLACEMENTS OF THE END STUDS 89 TABLE 7.1 EXPERIMENTAL TESTS RESULTS 92 TABLE 7.2 VERTICAL DISPLACEMENTS AND TILTING ANGLES 97 V LIST OF FIGURES FIGURE 1.1 JAPANESE CARPENTERS USING WOOD 1 FIGURE 1.2 JAPANESE ARCHITECTURE 2 FIGURE 1.3 TRADITIONAL JAPANESE CONSTRUCTION 2 FIGURE 1.4 PREFABRICATED HOUSES 3 FIGURE 1.5 FORCES ON A WALL ELEMENT 4 FIGURE 1.6 POST-AND-BEAM FRAME CONFIGURATIONS 6 FIGURE 1.7 CONNECTORS 7 FIGURE 2.1 SPD-LOADING SEQUENCES 10 FIGURE 2.2 YIELD DISPLACEMENT METHOD FOR SPD PROTOCOL 10 FIGURE 2.3 CEN - LOADING PROCEDURES 11 FIGURE 2.4 YIELD DISPLACEMENT METHOD FOR CEN PROTOCOL 12 FIGURE 2.5 MOC - LOADING PROCEDURE 13 FIGURE 2.6 YIELD DISPLACEMENT METHOD FOR MOC PROTOCOL 14 FIGURE 2.7 UBC LOADING METHOD 15 FIGURE 2.8 TEST FRAME 16 FIGURE 2.9 BRACING METHODS 18 FIGURE 2.10 TESTING SYSTEM - "T"-SHAPED MORTISE AND TENON JOINT 19 FIGURE 2.11 FRAME GEOMETRY 22 FIGURE 2.12 BEAM-COLUMN JOINTS 22 FIGURE 2.13 OSB PANELS 24 FIGURE 2.14 FOSCHI'S MODEL 25 FIGURE 2.15 SHEATHING-TO-FRAMING CONNECTOR ELEMENT 26 FIGURE 2.16 SHEATHING-TO-FRAMING CONNECTOR LOAD-DEFLECTION CURVE 27 FIGURE 2.17 FRAME-FRAME CONNECTION 29 FIGURE 2.18 HYSTERETIC CURVE 30 FIGURE 2.19 MODEL WITH CONTACT ELEMENTS 32 vi FIGURE 2.20 LOAD AND BOUNDARY CONDITIONS 33 FIGURE 3.1 2-BRACE FRAME 37 FIGURE 3.2 POST - GIRDER JOINT (DETAIL A) 38 FIGURE 3.3 POST - SILL JOINT (DETAIL B) 39 FIGURE 3.4 POST - SILL - BRACE JOINT (DETAIL C) 40 FIGURE 3.5 POST - GIRDER - BRACE CONNECTION (DETAIL D) 41 FIGURE 3.6 MABASHIRA-GIRDER JOINT (DETAIL E) 42 FIGURE 3.7 MABAS HIRA-SI LL JOINT (DETAIL F) 42 FIGURE 3.8 MABASHIRA-BRACE JOINT (DETAIL G) 43 FIGURE 3.9 4-BRACE FRAME 44 FIGURE 3.10 MABASHIRA-BRACE JOINT (DETAIL H) 45 FIGURE 3.11 OSB SHEATHED FRAME 46 FIGURE 3.12 SPECIFICATION OF THE JOINTS - OSB SHEATHED FRAME 47 FIGURE 3.13 " T " JOINT CONFIGURATION 48 FIGURE 4.1 FRAME TEST SET-UP 49 FIGURE 4.2 TRANSDUCER POSITION 52 FIGURE 4.3 LOADING PROCEDURE - UBC - MODIFIED PROTOCOL 54 FIGURE 4.4 " T " JOINT - TEST SET-UP 55 FIGURE 4.5 TRANSDUCER POSITIONS 56 FIGURE 5.1 LOAD - DISPLACEMENT CURVES 58 FIGURE 5.2 LOAD - DISPLACEMENT CURVES - OSB FRAME 59 FIGURE 5.3 YIELD DISPLACEMENT - OSB FRAME - MOC PROCEDURE 60 FIGURE 5.4 RACKING TESTS RESULTS - OSB FRAME 60 FIGURE 5.5 LOAD-DISPLACEMENT CURVES - 4-BRACE FRAME 61 FIGURE 5.6 YIELD DISPLACEMENT - 4-BRACE FRAME - MOC PROCEDURE 62 FIGURE 5.7 RACKING TEST RESULTS - 2-BRACE FRAMES 63 FIGURE 5.8 YIELD DISPLACEMENT - 2-BRACE FRAME - MOC PROCEDURE 64 vii FIGURE 5.9 TYPICAL DEFORMATION CONFIGURATION FOR SHEATHED FRAMES 65 FIGURE 5.10 NAILS PULLED OUT 66 FIGURE 5.11 NAILS PULLED THROUGH 66 FIGURE 5.12 NAILS PULLED OUT 67 FIGURE 5.13 MABASHIRA-SILL FAILURE 67 FIGURE 5.14 SILL FAILURE 67 FIGURE 5.15 STUD - SILL FAILURE 68 FIGURE 5.16 MABASHIRA - SILL FAILURE 69 FIGURE 5.17 MIDDLE STUD - SILL FAILURE 69 FIGURE 5.18 STUD-SILL FAILURE 70 FIGURE 5.19 MABASHIRA-SILL FAILURE 70 FIGURE 5.20 MIDDLE STUD - SILL FAILURE 71 FIGURE 6.1 RACKING AND CYCLIC LOAD - DISPLACEMENT CURVES FOR OSB FRAMES - MOC PROTOCOL 76 FIGURE 6.2 RACKING AND CYCLIC LOAD - DISPLACEMENT CURVES FOR OSB FRAMES - UBC - MODIFIED PROTOCOL 77 FIGURE 6.3 RACKING AND CYCLIC LOAD - DISPLACEMENT CURVES FOR 2-BRACE FRAMES - MOC PROTOCOL 78 FIGURE 6.4 RACKING AND CYCLIC LOAD - DISPLACEMENT CURVES FOR 2-BRACE FRAMES - UBC - MODIFIED PROTOCOL 78 FIGURE 6.5 RACKING AND CYCLIC LOAD - DISPLACEMENT CURVES FOR 4-BRACE FRAMES - MOC PROTOCOL 79 FIGURE 6.6 RACKING AND CYCLIC LOAD - DISPLACEMENT CURVES FOR 4-BRACE FRAMES - UBC - MODIFIED PROTOCOL 80 FIGURE 6.7 RACKING AND CYCLIC LOAD - DISPLACEMENT CURVES FOR 4-BRACE FRAMES - MOC PROTOCOL 80 FIGURE 6.8 NAILS PULLED THROUGH 81 viii FIGURE 6.9 NAILS PULLED OUT AT " CP-T" CONNECTOR 82 FIGURE 6.10 SHEATHED FRAME DISTORTION 82 FIGURE 6.11 SILL FAILURE - TENSION PERPENDICULAR TO GRAIN - END CORNERS 83 FIGURE 6.12 SILL FAILURE - TENSION PERPENDICULAR TO GRAIN - MIDDLE STUD 83 FIGURE 6.13 SILL FAILURE - TENSION PERPENDICULAR TO GRAIN 84 FIGURE 6.14 MABASHIRA - SILL FAILURE 84 FIGURE 6.15 MIDDLE STUD - SILL FAILURE 85 FIGURE 7.1 LOAD - DISPLACEMENT CURVES OF THE " T " CONNECTION 91 FIGURE 7.2 MAXIMUM CAPACITY VS. SPECIFIC GRAVITY - "T" CONNECTION 93 FIGURE 7.3 STIFFNESS VS. SPECIFIC GRAVITY - "T" CONNECTION 94 FIGURE 7.4 FAILURE MODE - SPLITTING OF THE SILL 95 FIGURE 7.5 FAILURE MODE - NAILS PULLED OUT 96 FIGURE 7.6 FAILURE MODE - METAL PLATE FAILURE IN SHEAR 96 FIGURE 7.7 TILTING ANGLE 98 ix ACKNOWLEDGEMENT I wish to express my deep appreciation to Drs. Frank Lam, David Barrett and Helmut Prion for their assistance and valuable suggestions throughout the project. My thanks are extended to Forest Renewal of British Columbia for funding support provided through my project and Ainsworth Lumber Co. for providing the OSB panels. I also express my thanks to Mr. Leo Oesterle, my colleagues Bingning Zhao and Dr. Liping Cai who have helped me to build the post-and-beam frames. x CHAPTER I - Introduction 1.1 Overview Ancient Japanese architecture is known for its use of wood in construction of houses, temples, or castles (Figure 1.1).