Ramberg-Osgood土动力非线性模型在ABAQUS软件上的开发及应用

Development and application of Ramberg-Osgood soil dynamic nonlinear constitutive model on ABAQUS code

基于ABAQUS有限元软件开发平台,对Ramberg-Osgood土动力非线性本构模型进行了修正。通过合理的假设得出了模型修正参数、R的取值方法和算法。滞回曲线加卸载规律符合修正后的Masing准则。并进行了三维场地地震动非线性分析,分析了不同输入峰值的地震波对土体应力-应变关系的影响,并与一维场地动力分析Shaking程序的计算结果进行了比较。分析结果表明,非线性分析时的水平位移和相对位移要大于等效线性情况下的相应位移,这表明采用何种本构关系将影响到得到的场地的地震动反应结果,因此,在工程应用时需加以合理的选择,并对最终结果做出合理的判断。

Based on the ABAQUS finite element code, the soil dynamic nonlinear constitutive model of Ramberg Osgood has been modified. Based on the appropriate assumptions, the procedure and the algorithm for evaluation of the model＇s parameters R and tz are derived. Loading and unloading rules of the hysteresis correspond to the revised Masing criterion. Threedimensional nonlinear ground seismic analysis has been performed, the influence of seismic waves with different input peak value on soil stress-strain relationship has been analyzed, and the results have been compared with that of the one-dimensional soil dynamic analysis on Shaking code. The results show that the horizontal displacement and relative displacement obtained by the nonlinear analysis are greater than that obtained by equivalent linearization method, which indicates that the selection of constitutive model will affect the obtained results of ground seismic response; thus it is necessary to select the appropriate model in engineering application and make reasonable judgments for the final result.