Analysis Of Seismic Performance Of Damaged Wooden Frame Based On Energy Conversion

In order to study the impact of damage on the seismic performance of ancient wooden structures,this article refers to the relevant regulations on third-timber timber framing in "Building Method" and "Technical Specifications for Maintenance and Reinforcement of Ancient Architecture",and establishes a third-grade timber intact model and damage model.The horizontal monotonic static loading experiments of the three-level timber frame under different vertical weights were simulated,and the overall deformation of the wooden frame and the mass block lifting were analyzed,and the relationship between the horizontal restoring force and loading displacement was obtained.The results show that with the increase of the vertical counterweight at the top of the column,the smaller the dovetail tenon drawing and the mass block lifting,the greater the structural rigidity and bearing capacity of the wooden frame.Simulation of third-class wood timber frame under different vertical counterweight horizontal reciprocating static load experiment,the analysis of timber frame deformation characteristics,hysteretic characteristics,stiffness and energy changes,and will be in good condition model compared with the pseudo-static results of the damaged model,the results show that the vertical weight increases as the pillars,timber frame is loaded into the same amount of force required horizontal displacement increases,the stiffness of the structure increases,the area of the hysteresis curve hysteresis loopback envelope is bigger,"pinch approach" effect more significantly;The energy in the input structure is mainly converted into gravitational potential energy,hysteretic energy dissipation and elastic strain energy;Compared with the intact model and the damaged model,the dovetail tenoning amount of the intact wooden frame is less than that of the damaged wooden frame,and the tenoning phenomenon is more obvious as the degree of damage increases;Analysis of hysteresis curve,stiffness degradation curve and skeleton curve,the curve of the damaged model change trend and intact model are similar,but the damage reduced hysteresis curve of plumpness,intact model of restoring force,bearing capacity and resistance to lateral stiffness were greater than the damage model,and the more serious the damage phenomenon,timber frame of restoring force,bearingcapacity and resistance to lateral stiffness is smaller;Through comparative analysis of the energy conversion,the energy conversion in the damaged timber frame system is similar to that in the intact timber frame,but the hysteretic energy dissipation and elastic strain energy ratio of the damaged timber frame are slightly larger than that of the intact timber frame.The more serious the damage is,the more obvious the sliding phenomenon is,and the more unfavorable it is to the earthquake resistance.Simulation of intact and damaged timber frame for quasi-dynamic experiments,first through the structure of the free vibration of the analysis of the natural vibration frequency of the timber frame,in the condition of resonance through the application of simple harmonic,simple harmonic frequency,constantly changing the amplitude,in order to produce the maximum dynamic response to analyze the dynamic characteristics of the timber frame.The results show that the relative displacement of the column top and bottom of the intact timber frame is smaller than that of the damaged timber frame when the frequency and peak acceleration of sinusoidal excitation are the same,and the greater the degree of damage,the greater the relative displacement.It shows that the seismic performance of the damaged wooden frame decreases,and the greater the degree of damage,the more unfavorable to the seismic performance.