结构三维非线性分析软件Opensees的研究及应用.pdf

摘要摘要有限元数值分析方法是了解结构抗震性能的重要方法之一。随着电脑的迅速发展和普及,许多结构有限元分析软件如Sap2000、Etabs、 PKPM等迅速发展并在工程中得到了广泛的应用。这些软件均有一个相对友好的用户界面和强大的弹性反应分析功能,但非线性分析功能十分有限。Opensees和Canny99是近年发展起来的三维非线性分析软件, 主要特点是用纤维单元模型较好的实现了构件的三维非线性反应分析, 但它们基本没有前后处理功能,建模和结果分析均十分繁琐,距离实用还有一定距离。本文研究了目前较为先进的几种结构三维非线性分析软件中的主要分析模型,并比较了它们的优缺点。研究了柔度法形成构件单元刚度矩阵的计算原理及有限元分析过程中用柔度法形成构件单元刚度矩阵时的迭代求解过程。研究了Opensees中基于纤维模型的梁柱单元的计算原理,并将其与Canny99中的纤维模型做了详细的比较。 Opensees中没有非线性剪力墙单元,本文用Opensees中的非线性梁柱单元加入剪切弹簧来模拟剪力墙。对一个三层剪力墙进行数值模拟,模拟结果与实验结果符合较好。为了简化Opensees的建模工作,作者开发了Sap2000模型向 Opensees模型转换的程序,它能将Sap2000中的模型直接导入到 Opensees中进行计算,大大简化Opensees的建模工作。Opensees 中没有非线性剪力墙单元,程序在导入Sap2000中的剪力墙构件时, 将其用加入剪切弹簧的非线性梁柱单元模拟,并将模拟剪力墙的非线性梁柱单元与其他梁柱单元用刚性梁连接起来。通过几个算例表明,所编程序能正确的将Sap2000的模型导入到Opensees中,且程序中对剪力墙的处理方式能较好的模拟实际剪力墙结构的反应。关键词:纤维模型三维非线性反应剪力墙中田地震局T程力学研究所硕f‘学位论文 Abstract The 6nite element method e an important problem—solving alternative to analysis structure earthquake puter es very popular nowadays,many finiteelement software packages such as andPKPM are developed and widely used in the engineering of those SOftware packages have a relatively interface and strong ability toanalysis the elastic response of structures,but their nonlinearity analysis function isvery and Canny99 are the latestnonlinear finite element software Opensees and Canny99 mainly use fibermodel to model three dimensional nonlinear response of both Opensees and Canny99 don’thave pre and post it'Sdifferent to use are wide distance from practice use. This paper had researched mainly models of some advance finite element softwares,researched thecalculate principle when use flexibility method toform thestiffnessmatrix theprocess of iteratewhen use flexibility method tOforillthestiffness matrix ofelements andthefibermodel ofOpensees andCanny99. Add an element which iSused tomodel theshear deformation intothe fiber model inOpensees tomodel Reinforee