Nonlinear Time-history Analysis And Energy Research Based On Double-linear Restoring Force Model

As is known to all, the earthquake caused great damage and loss to our life andproperty security, so further study of seismic method has become urgent. Seismicdesign method based on energy can not only contains force and displacement, whichare two important parameters of the structure, but also can consider cumulativehysteretic energy which represent the structural damage, and avoided insufficient ofnonlinear displacement based on bearing capacity and response spectrum method, andcannot consider the cumulative damage of structure. Seismic design method based onenergy can comprehensively reflect the influence of earthquake to structure and theseismic performance of structure, the precondition of the study of energy method isable to accurately calculate time-history response. This paper, which is based onpredecessors’ research results, accurately obtain the calculation method of nonlineartime-history response through systematic theoretical research and a large amount ofcalculation, and have establish the SODF (Single-Degree-Of-Freedom) and MDOF(Multiple-Degree-Of-Freedom) nonlinear energy spectrum. The main content of thepaper is as follows:1. Take an in-depth study for step-by-step integral method which is Newmark-method in this paper, get an unconditional convergence program of the application ofstep-by-step integration method through Matlab software, establish the SDOF andMDOF linear and nonlinear model through Matlab software respectively, at the sametime, establish the corresponding SDOF and MDOF linear and nonlinear model inANSYS finite element analysis software through the COMBIN40unit, using thetransient analysis to simulate the ground motion input;2. Compare the Matlab and ANSYS results respectively in condition of theSDOF linear without damper under simple harmonic load and linear SDOF systemunder the action of seismic wave to discuss the Matlab program in calculationaccuracy and convergence;3. For double linear restoring force model, five different inflection pointprocessing method is proposed, in order to seek the most effective method of SDOF nonlinear system under the action of seismic wave, compare and verify the Matlaband ANSYS results respectively under the condition of2DOF nonlinear system underthe action of seismic wave and the condition of the3DOF nonlinear system under theaction of seismic wave situation, through the comparison and error in time-historyanalysis, average error and verify the dynamic balance equation, find the mosteffective inflection point processing method;4. To verify the energy balance equation, the total input energy, the calculationmethod of damping energy and hysteretic dissipation energy, draw the energyspectrum of nonlinear SDOF and nonlinear MDOF system; To analyze the influencefactors of total input energy, look for ways to minimize the total input energyoptimization.