Experimental Study Of Traditional Chuan-dou Frames With Infill Under In-plane Cyclic Load

The Chuan-dou type of structure is the main form of traditional timber structure widely spread in villages and towns in the southern area of China.This type of structure has the features of smaller cross-sectional dimensions,a simple style of connection,and has the advantages of convenient and cost-effective construction.So far,many villages and towns in rural areas still adopt such architectural forms.In the past research and field investigation,it is found that wood infill wall and masonry infill wall are the two main forms of infill wall in the Chuan-dou structures.At present,At present,the existing domestic and foreign researches mainly focus on the frame.For the Chuandou type of structure with infill walls,research on the seismic performance of which is not comprehensive yet.This research adopts the typical wood and masonry infill walls in the existing structures as the main infill wall forms to design and manufacture test specimens and conduct the pseudostatic test to study their seismic performance.Seven specimens have been tested.K1 is a frame test specimen,and the test purpose is to compare with others with infill walls.K2,K3,and K4 are test specimens with wood infill walls.Different panel assembly and reinforce methods are applied.K5,K6,and K7 are filled with masonry walls with different mortar types and tie reinforcements.Based on experimental results,the failure mechanism,hysteresis and skeleton curve,stiffness and strength degradation,and energy consumption of the seven specimens are obtained.The results show that the infilled wall can effectively improve the bearing capacity,lateral stiffness and energy dissipation capacity of the specimen.For the specimens with wood panel infills,the out of plane displacement of the panel is more obvious in the horizontal assembly;The out of plane deformation of the wallboard can be limited by the reinforced panel.For the specimens with masonry infilled wall,the failure development can be divided into three stages:elastic deformation stage,bottom crack development stage and rigid body rotation stage;The results show that the specimens with tie bars have higher bearing capacity.Through experimental research and literature review,ABAQUS is adopted to establish a refined finite element model and adjusted with the experimental results.Different types of infill walls with different lateral stiffness and load-bearing capacity have been simulated,as well as different reinforcement methods and connection forms.Based on the test results and finite element analysis and simulation,the theoretical model and calculation method are proposed,which provides a reference for studying the seismic performance of Chuan-dou structures with infill walls.The results shows that the finite element model established in this paper is reasonable for the prediction of test results.For the specimens with wood panel infilled wall,the initial stiffness and bearing capacity of the specimens are improved by increasing the width,thickness of the wall panel and the height of the beams.At the same time,the extrusion and friction between adjacent panels and between panels and wood frames are the main sources of resisting bending moment.For the specimens with masonry infilled wall,compared with the calculation method of masonry cracking load in the Chinese national standard,the calculation results in the FEMA are closer to the test results;When the cracks at the bottom of the masonry infilled wall are fully developed,if the horizontal thrust of the specimen exceeds the theoretical value of triggering the rocking effect,and the column base can rise freely,the rigid body rotation will be dominant.