Lateral Resistance Performance Analysis And Performance Improvement Technology Research Of Chuan-dou Style Wooden Structure

Traditional villages and dwellings in China carry great historical and cultural information.They are valuable living cultural heritage,the soul of our nation,the root of culture,the wealth of our country and the treasure of the world.The protection of traditional villages and dwellings has been incorporated into the outline of the 13 th five-year plan and the 14 th five-year plan.As one of the essential structural forms of traditional dwellings,Chuan-Dou style wooden structure is widely distributed in Southwest China.It has rich stock and is the main structural form of new dwellings.This structure uses small-size components,and the components are connected by mortise and tenon.Under the strong wind and earthquake,it is prone to tenon pulling,tenon breaking,column foot sliding,filled wall collapse,wooden frame inclination,and even collapse,which seriously threatens the safety of people and property.Therefore,it is urgent to put forward scientific and reasonable reinforcement measures to ensure the safety of the structure.Comprehensive knowledge of the mechanical properties of structural joints and systems is the premise of this work.At present,the research on the beam-column joint of Chuan-Dou style wooden structure mainly focuses on the mechanical performance of straight mortise-tenon joint and exterior joint,there is little research on joint with wooden peg and interior joint of the structure,and the weak part of the structure is not clear.The experimental method is generally adopted to research the mechanical performance of the Chuan-Dou style wooden structural system,and the obtained conclusion is not universal.In addition,the research on the influence of different infills on the lateral-resisting behavior of wooden frames is not comprehensive.In view of the above problems,based on the unique structural characteristics of the Chuan-Dou style wooden structure,the moment-resisting performance of the critical beam-column joints and the lateral-resisting performance of the structure are researched in this paper.In addition,the reinforcement measures for the weak parts of the structure were put forward and evaluated.The primary researches of this paper include the following contents:(1)Based on the construction and position in the structural system of the beam-column joint of the Chuan-Dou style wooden structure,the mechanical analytical models of the critical beam-column joint of the structure are extracted.Through experimental research and theoretical analysis,the failure modes,flexural capacity,flexural stiffness and hysteretic behavior of exterior straight mortise tenon joints without wooden peg,exterior straight mortise tenon joints with wooden peg,interior straight mortise tenon joints with wooden peg and mortise-tenon lapped joint with wooden peg is obtained.The simplified moment-rotation mechanical model of these joints is established.By comparing the failure modes and moment-resisting performance indexes of the four types of joints,the weak joints of Chuan-Dou style wooden frame are identified.(2)The experimental tests are carried out on the transverse and longitudinal Chuan-Dou style wooden frame under lateral loading.The failure mode,lateral-resisting stiffness,capacity,and energy dissipation of these two wooden frames are compared and analyzed.The weak wooden frame is identified.(3)The spring element with zero-length and zero-mass is introduced to simulate the semi-rigid mortise-tenon joints and column foot joints.The second-order elastic analysis method of semi-rigid Chuan-Dou style plane wooden frame is proposed.The theoretical model of the lateral load-displacement curve of Chuan-Dou style wooden frame is established.By comparing the tested results and theoretical curve of the wooden frame,the rationality of the theoretical model is verified.The influence of column spacing and moment-resisting stiffness of mortise-tenon joint on the lateral-resisting behavior of the structure is analyzed.(4)The low frequency cyclic reversed test of Chuan-Dou style wooden frame with infills is carried out.The damage and failure modes of wooden frames infilled with wooden panels and masonry panels are obtained.The effects of wooden panel infills and masonry infills on the lateral-resisting stiffness,lateral-resisting capacity and hysteretic performance of Chuan-Dou style wooden structure are compared and analyzed.(5)The self-tapping screws reinforcement is put forward for the exterior straight mortise-tenon joint.The failure mode,moment-resisting capacity,flexural stiffness,and hysteretic performance of self-tapping screw reinforced joints and traditional cramp reinforced joints are obtained through monotonic and cyclic tests.The reinforcing effects of the two schemes are compared and analyzed,and the results show that the self-tapping screw reinforcement scheme is prior.Then,the influence of the diameter and strength of self-tapping screws on the moment-resisting performance of the joint is discussed by numerical simulation.The reinforcement scheme of the spring damper is proposed for the mortise-tenon lapped joint.Through the experimental test,the influence of the number and layout of spring dampers on the flexural performance of the joint is analyzed,and the reinforcement effect of spring damper is evaluated.