Research On Steel Constitutive Model On Xue-Wierzbicki Damage Criterion And Damage Accumulation Effect Of Reticulated Shells

With the national economic and social developing,the Space Structure has been widely used in a variety of large-scale public facilities.Because of its structural form,the mechanical performance is reasonable,it is very good to meet the requirements of the large span buildings,and it has become one of the most rapid development in recent years.Along with a large number of applications in the earthquake zone,and the lack of a reasonable and feasible design method of the reticulated shell structures,the seismic theory research has been concerned by scholars at home and abroad.As is known to all,the reticulated shell structure is a kind of unique structural form,its structural performance and design analysis method have many characteristics with the traditional structure.In the early stage of the reticulated shell structure,the seismic analysis of the steel structure model is assumed to be an ideal elastic-plastic model.However,the damage accumulation of the material can not be ignored because of the serious plastic damage in the failure time.Therefore,using more accurate material constitutive model is the key to obtain the seismic response of reticulated shell structures,which is of fundamental significance for a series of related researches in this field.Based on the above problems,the tubular spatial hysteresis characteristic as the basis of experimental data,by using the finite element software ABAQUS microscopic damage to simulate the initial time of steel material damage and materials into the development process after entering the injury,to fit the experimental data obtained the material damage constitutive parameters,and then before the subroutine method were compared and analyzed,and studying the effect of material damage and collapse of the seismic response of reticulated shell structure.The main research contents of this paper are as follows:First of all,basing on the Xue-Wierzbicki damage criterion,material damage constitutive model is considered by the application of finite element software ABAQUS,the performance test of steel tube space lag back to numerical simulation,constitutive model were determined by the unknown parameters in the model of each component,and by least squares fitting to determine the cumulative damage constitutive equation considering the steel.Then,the numerical simulation and verification of the test and structure shaking table test are carried out by using the obtained steel constitutive model(XW-S235).Comparison of the user material subroutine simulation method,the simulation results obtained in this paper agree better with the experimental results,proved the convergence ability of the constitutive equations proposed in this paper has higher accuracy and better.To further discuss the influence of structural damping and material damage cumulation effect on seismic response of shell structure,the constitutive model(XW-S235)is applied to the single-layer reticulated shell structure,the comparison of the simulation schemes with the non structural damping,as well as the ideal bilinear constitutive model and the constitutive model based on the UMAT subroutine is carried out.By comparison,the structural damping and material damage accumulation effect on the seismic response of reticulated shell structure has obvious effect,therefore,this can be considered at the same time the cumulative structural damping and material damage constitutive model has the advantage of better.Finally,the seismic response analysis of single layer spherical,cylindrical,saddle shell structures and large span double-layer spherical reticulated shell structures is carried out.The cumulative effects of material damage on the parameters such as span,rise span ratio,roof quality and initial defects were investigated,and the influence of damage accumulation on seismic capacity of reticulated shell structures was summarized.