Simulation Study On The Seismic Performance Of Single And Double Span Timber Frame

Chinese ancient timber structure buildings have exquisite appearance,complex combination form and excellent seismic performance,which show the wisdom of the ancients to posterities and transmit the culture of the Chinese nation.Studying the seismic performance of timber structure is necessary to protect the ancient timber structure buildings.Many ancient timber structure buildings are based on multi span structure,but studies now are mostly based on single span timber frame,less studies refer to double and multi span timber structural performance,and their mechanics performance and seismic performance need further study.This paper based on the performance experiment of sylvestris,use the fourth grade wood in Yingzao Fashi as prototype and finite element software Abaqus to build 3 single span timber frame models with different size of dovetail,single and double span timber frame models with Tou-Kung and without Tou-Kung,then conducts the simulation calculation analysis to them.This experiment conducts pseudo static test simulation to 3 single span timber frames with different size of dovetail under different additional weight to the pillar top,to know their structural deformation characteristics under horizontal displacement reciprocating loading,and gets the P-? hysteresis curves,skeleton curves and stiffness degradation curves of the frame according to the simulation results,also sets up the restoring force model.The analysis result shows that timber frame has good energy dissipation capacity,and the lateral stiffness and total energy consumption of the frame will increase with the increase of additional weight.The size change of the dovetail tenon will influence the structural lateral stiffness: when the dovetail tenon is small,its gripping force will increase because of the change of the pillar top section,making the structural lateral stiffness bigger than timber frame with bigger tenon;when there is a tiny gap in the end of dovetail,the skeleton curve almost coincides to the skeleton curve of dovetail without gap in the end.This experiment also conducts pseudo static and dynamic test simulation to single and double span timber frames with and without Tou-Kung under different additional weight.This paper analyzes their hysteretic characteristics under horizontal displacement reciprocating loading,and makes comparisons to their skeleton curves.Under EI Centro seismic wave load,there are relative displacement-time curves and acceleration-time curves of different structural heights.The result shows that structural seismic response is influenced by the additional weight to the structural top: the relative displacement peak value between the structural upper and lower part will increase with the increase of the additional weight,and the acceleration-time curve's cycle will increase with the increase of the additional weight as well.This experiment makes comparisons on the structural relative displacement under EI Centro seismic wave load between single span and double span timber frame.When the additional weight is 3,the relative displacement peak value between pillar top and bottom plate of none Tou-Kung double span timber frame is bigger than the relative displacement peak value of none Tou-Kung single span timber frame,when the weight of the pillar top increase to 6 and 9,the relative displacement peak value between pillar top and bottom plate of none Tou-Kung double span timber frame is smaller than the relative displacement peak value of none Tou-Kung single span timber frame.The relative displacement peak value between shuatou and bottom plate of double span timber frame with Tou-Kung is bigger than the value of single span timber frame with Tou-Kung under 3 level additional weights.