Study On Analysis Method Of Seismic Performance Of Aged Timber Structure With Existing Damages

Aged timber structure is a gem of traditional Chinese ancient architectural art,carrying the glorious civilization of China for more than five thousand years.It is an important historical and cultural heritage in our country.Many of the existing aged timber structures have experienced many earthquakes in history and stand upright.However,with the increase of service life,aged timber structures inevitably have been suffered from material degradation,structural deformation and other damage.Obviously,the analysis method of aged timber structure with existing damage under earthquake action is the key to study the seismic performance of ancient buildings,the research on the seismic performance of aged timber structure with existing damage is an important basis for its maintenance and reinforcement,and also a problem to be solved in the field of aged timber structure protection.In this paper,the seismic performance of an aged timber structure with existing damage is studied,and the following three aspects are mainly complete:(1)By referring to the relevant literature such as "building method",taking the most characteristic bucket arch node in the aged timber structure as the breakthrough point,the structural characteristics of the bucket arch and the elastic-plastic material parameters of the wood are analyzed.Based on this,the finite element model of the bucket arch is established in ANSYS.(2)The bucket arch joint is regarded as the research object.Based on the symmetry of load and boundary conditions,the finite element analysis model is established by taking 1 / 2 typical bucket arch joints.And the bearing capacity curve under the vertical load and the hysteretic curve and skeleton curve under the horizontal low cycle reciprocating load are obtained respectively.According to the fitting results of the bearing capacity curve,the vertical mechanical properties of the bucket arch are simplified into a trilinear model,and the horizontal mechanical properties of the bucket arch are simplified into a bilinear model according to the fitting results of the skeleton curve.And the influence of different vertical loads on the horizontal mechanical properties of the bucket arch is analyzed(3)Taking an aged timber temple hall with existing damage as an example.Based on the field survey results,the mortise joints,the bucket arch joints,the column base joints and the maintenance wall are simplified and the whole intact and damaged finite element models are established respectively,and the modal analysis results of the model are compared with the results of the field vibration test to verify the rationality of the finite element model.The seismic response of the intact structure and the damaged structure in VII degree earthquake and fortification earthquake is obtained by response spectrum analysis,and the seismic response of damaged model of VII degree rare earthquake,VIII degree rare earthquake and Ⅸ degree rare earthquake is obtained by time history analysis.Taking the typical column and beam brace system of the wood structure as the research object,the deformation differences of the completed structure and the damaged structure under different earthquake actions are analyzed,and the overall structure with damage is evaluated The aseismic performance and the suggestions in the later maintenance and reinforcement are given.