黄土非线性本构模型参数反演

【作者】 崔伟华；

【导师】 刘增荣；

【作者基本信息】 西北工业大学 ， 结构工程， 2004， 硕士

【摘要】 通过位移反分析来确定初始参数已经成为工程发展的需要。对于线弹性问题的反分析已经做了大量的工作，并且取得了很多成果，但对于非线性问题的位移反分析目前只是处于研究和探讨阶段，没有形成成熟的理论和方法。对于黄土非线性本构模型参数的反演工作就做的更少。 本论文用正演和优化相结合的方式对黄土的非线性本构模型中的参数进行反演。优化方法采用的是近几年发展很快的一种新型算法——遗传算法，此算法在函数优化领域得到了广泛的应用，本论文用遗传算法的基本思想，结合实际问题独立编制了C语言程序，用遗传算法对黄土的非线性本构模型参数进行优化。正演方法采用数值方法中的有限单元法，用现在应用广泛的有限元计算软件进行正演计算，并首次在ANSYS实现了对土的非线性弹性模型的计算。用工程实例验证了用遗传算法进行位移反分析的可行性。 本论文所作的工作提供了这样一种思路，依据建筑物建造之前，从地基土载荷试验中获取的试验数据，通过由遗传算法所建立的黄土非线性本构模型参数反演的方法，可以进行黄土非线性本构模型参数的优化识别。而由识别出的参数，可以对建筑物构造后的黄土土体变形进行较高精度的预测。 本论文从新的侧面，促进了对黄土非线性本构模型参数反演的研究，对于正确的选用黄土非线性本构模型参数，提高土体变形稳定分析的精度，具有一定的参考价值和理论意义。更多还原

【Abstract】 With the development of the main engineering, we need educe the parameter by displacement back-analysis. Now, we have done much research in the problem of liner elastic model, and obtain much achievement. But less research have been done in the problem about nonlinear model. The research on the back analysis of nonlinear model is in the stage of start. We have not some certain appropriable method to solve this problem. More less job has been done on the loess nonlinear model.This paper use a method to educe the parameter by coincide optimization and forward-analysis. This method is genetic algorithm-a new method to make optimize, it develops very fast lately and has been largely used in function optimizing. According to its basic ideology, I write a C program to complete soil parameter optimize. The forward-analysis method is finite element method. By some software I realize the forward -analysis calculation, and realize the calculation of Duncan-Chang model. It’s feasible to execute displacement back-analysis by Genetic Algorithms by engineering example.This paper provides a process: according to the experimental data from the groundsill load experiment, we can identify the parameter of the loess nonlinear model by using the genetic algorithm before construct the building. By the parameter we can forecast the groundsill distortion.This paper advances the study of the parameter back-analysis of loess nonlinear model from a new side. It has certain reference value and theory significance for how to select the parameter of loess nonlinear model and promoting the stabilization analysis precision of soil distortion.更多还原