Simulation And Analysis Of Bearing Behavior Of Multi-span In Ancient Timber Structure

In order to study the load-bearing performance of multi-span timber frame,the finite element model of single,double and triple span timber frames were established by using ABAQUS finite element analysis software with reference to Song “Building Method”.The horizontal low-cycle reciprocating loading was simulated under different column top weights,and the hysteresis curves,skeleton curves,stiffness degradation curves of the timber frame under different column top weights under three different spans were obtained.A resilience model of the timber frame was established.The results show that the hysteresis curves of the three different spans of wood frames have “pinching”;under the same column top load,with the increase of the number of spans,the degree of “pinching”decreases,and the hysteresis curve consists of “Z”.“The shape transitions to the bow shape,the resistance to lateral stiffness of the timber frame increases,the rate of degradation of the stiffness becomes slower,the enveloping area of the hysteresis curve increases,and the total energy consumption of the structure increases;as the weight of the column top increases,the hysteretic curve With less plumpness,the "pinching" phenomenon is more pronounced,the horizontal lateral stiffness of the timber frame increases,the area of the hysteresis loop is larger,and the energy dissipation capacity and seismic resistance are enhanced.For the sine wave with different initial displacements and different acceleration peaks under the same column top load,the dynamic characteristicsof three different span wood frames were analyzed and the free vibration of three different span wood frames was obtained.Curve,relative displacement time history curve and acceleration time history curve at the top of the column top.The results show that with the increase of the initial displacement of the timber frame,the period of natural vibration becomes larger and the natural frequency decreases.With the increase of the number of spans under the same column load,the resistance of the timber frame against sinusoidal excitation has an increasing trend.The relative displacement time histories at the bottom are similar,and the timber frame collapses in the transient response phase,and the maximum displacement occurs in the transient response phase;the top of the column acceleration curve has obvious transient response segments at the initial stage of excitation,while the bottom acceleration curve enters the steady state stage immediately.The time-history curves of the column top and column bottom have obvious “beating” phenomenon after vibration stabilization.The frequency is consistent but not at the same time;if the sinusoidal excitation has a small peak acceleration,the power amplification factor is greater than 1,the wood The shock-absorbing effect of the structure is not obvious.After the excitation peak acceleration is increased to a certain extent,the timber frame can only exert its shock absorption characteristics.