Experimental Study And Engineering Demonstration Of Seismic Performance Of Traditional Wooden Structure Mortise And Tenon Nodes Reinforced By Viscoelastic Dampers

Traditional timber-framed dwellings in southwest China are an essential part of the country’s architectural heritage.However,rapid industrialization,urbanization,and agricultural modernization have caused varying degrees of damage to many of these structures.The most severe damage often results from problems with mortise and tenon joints.To address these issues and respond to the call of the 14 th Five-Year Plan for the revitalization of the countryside,this paper proposes a method to strengthen the mortise and tenon nodes of wooden structures with corner braced viscoelastic dampers.This paper aims to achieve the following objectives:(1)Propose the use of corner braced viscoelastic dampers as a reinforcement method for traditional timber frame dwellings.The mechanical properties of viscoelastic materials,such as loading frequency,strain amplitude,ambient temperature,and fatigue,are analyzed through static tests.The results show that loading frequency,strain amplitude,and temperature have a significant impact on the mechanical properties of viscoelastic damp ers,while fatigue has a minor effect.(2)Test the physical and mechanical material properties of Yunnan pine wood and design test pieces according to the types of mortise and tenon used in traditional timber-framed dwellings.Low-period repeated load tests are conducted on unreinforced and reinforced mortise and tenon nodes,where the reinforcement is divided into three types: single-sided unreinforced nodes,single-sided reinforced damaged nodes,and double-sided reinforced nodes.The seismic performance of traditional timber mortise and tenon nodes is significantly improved after reinforcement with viscoelastic dampers,as indicated by hysteresis curves,skeleton curves,stiffness degradation curves,energy dissipation capacity,and node-pulling phenomenon.(3)Conduct numerical simulations of unreinforced nodes using the finite element analysis software ABAQUS and compare the results with those obtained through low circumferential repeated load tests.The results show that the finite element analysis structure matches well with the test results.(4)Derive the moment-turning angle mechanical model of the reinforced node as a whole based on the geometric deformation of the corner braced viscoelastic dampers in the reinforced additions,the mechanical equil ibrium,and the mechanical model of the traditional timber mortise and tenon node.(5)A corner-supported visco-elastic damper has been placed in the ’one seal’ structure of a typical south-western timber-framed traditional house to improve the redundancy and safety of timber-framed buildings and bring traditional timber-framed houses back into use.