Theoretical And Experimental Research On Seismic Performance Of Full-scale Traditional Chinese Timber Frame In Song Dynasty

This paper has carried out experiments and theoretical investigations on traditional Chinese wooden structures,and conducted a pseudo-static test on a typical traditional wooden frame in the Song Dynasty,and analyzed the deformation characteristics and stress characteristics of the wooden frame under the action of horizontal force.Based on the experimental analysis A quantitative assessment of the recovery of the Song Dynasty wooden frame under the action of horizontal force was carried out;on this basis,a dynamic analysis model of the traditional wooden frame of the Song Dynasty was established to explore the initial dynamic response of the Song Dynasty wooden frame under the action of horizontal acceleration and The factors that affect its initial dynamic response are analyzed;on the basis of the analysis model of the rocking wooden frame,the initial motion state of the rocking wooden frame under the combined action of horizontal and vertical acceleration is further investigated.The main conclusions are as follows:(1)The Song-style single-span timber frame was designed according to "Building Method".Under the design idea of quasi-static experiment,the experimental design of singlespan traditional timber frame was carried out.Analyze the static experiment to get the hysteresis curve,skeleton curve,stiffness degradation and viscous damping coefficient of the Song-style single-span timber frame,which shows that under the traditional concept,the timber frame has good deformability(interlayer displacement angle up to 1/23),but its rigidity and energy dissipation capacity weaker.At the same time,the residual displacement,displacement recovery coefficient,initial stiffness degradation and interlayer displacement concentration coefficient of single-span timber frame were investigated.The displacement recovery coefficient is between 0.85 and 1,and the wooden frame has good displacement recovery ability.The initial stiffness degradation is more significant only when the horizontal displacement is less than the yield displacement.The results show that the values of the inter story displacement concentration factors between 1.22 and 1.68 are all greater than 1,which means that the column frame layer is the deformation concentration area of the wooden frame under horizontal load.(2)A dynamic theoretical analysis model that can characterize the rocking characteristics of the Song-style timber frame was established,and the distribution law of its initial motion state under horizontal acceleration was obtained and the factors affecting it were discussed.The friction coefficient between banse and column bottom(between 0.3 and 0.9),height to diameter ratio(between 6 and 20)and mass ratio(between 0 and 112).There are four types of initial motion states: relative static,relative slip,rocking,and slip rocking.At the same time,the time history analysis of 121 sets of finite element models were carried out,and the numerical distribution of the initial motion state of the 121 sets of models is obtained,and that is consistent with the theoretical distribution of the initial motion state.(3)On the basis of the theoretical analysis model of Song style traditional wooden frame in this paper,the horizontal and vertical accelerations are applied at the same time,and the initial dynamic response of the wooden frame under the coupling action is obtained.By comparing with the initial motion state under horizontal acceleration,it is found that the vertical acceleration has a significant effect on the initial dynamic response.And 588 sets of nonlinear finite element models are used to verify the effectiveness of this theoretical model.(4)The analysis model proposed in this paper can reveal the self-similarity of the initial dynamic response of the Song-type rocking wooden frame,provide a theoretical basis for the inquiry of the similarity of the dynamic response of the Song-type rocking wooden frame,and design the dynamic experiment of the Song-type rocking wooden frame.for reference.