基于ABAQUS的粘弹性边界单元及在重力坝抗震分析中的应用  

Viscous-spring boundary element based on ABAQUS and application to dynamic analysis of a gravity dam

作　　者：陈灯红[1] 杜成斌[1] 苑举卫[1] 

机构地区：[1]河海大学工程力学系,江苏南京210098

出　　处：《世界地震工程》2010年第3期127-132,共6页World Earthquake Engineering

基　　金：973课题子题(2007CB714104);中国水利水电科学研究院开放研究基金项目(2008538613);江苏省普通高校研究生科研创新计划项目(CX09B_155Z)

摘　　要：考虑了2种不同的地震输入模型,即无质量地基模型和考虑辐射阻尼的粘弹性边界模型。以大型非线性有限元程序ABAQUS为平台,采用FORTRAN语言开发了用户单元子程序VSB_UEL.for,将粘弹性边界有效地嵌入到ABAQUS中。在尽量避免求解自由场的前提下,将离散的地震荷载转化为等效结点荷载,编写的计算程序可以方便地将等效荷载施加到人工边界结点上,并通过数值算例验证了粘弹性边界单元及波动输入程序的正确性,其求解效率和计算精度均令人满意,最后将该程序应用到在建的某水电站厂房坝段的抗震分析中。结果表明,与传统的固定边界无质量地基相比,考虑了粘弹性人工边界后,坝体的动力响应峰值减小了20%~40%;在进行结构动力响应分析时,考虑无限域地基的辐射阻尼影响是很有必要的。文中的用户子程序及波动输入程序很容易扩展至三维,为同类工程的抗震分析提供了简洁、合理的计算模式。In this study,two different earthquake input models are presented,i.e.massless foundation model and viscous-spring boundary input model considering radiation damping.Based on the commercial nonlinear finite element code ABAQUS and the user element subroutine VSB_UEL.For,viscous-spring boundary element is developed by FORTRAN language,thus viscous-spring boundary is embedded into ABAQUS.For avoiding the free field being solved,the discrete seismic load is translated into equivalent nodal load,which could be applied to the nodes of artificial boundaries conveniently by the compiled computer program.The correctness of viscous-spring boundary element and wave input program are proved by a numerical example,their solution efficiency and calculation precision are both satisfied.Finally,the viscous-spring boundary element and wave input method are applied to the dynamic analysis of the power house section of a hydropower station which is being built.The results show that when viscous-spring boundary is considered and compared with the traditional fixed boundary of massless foundation,the peak value of dam＇s dynamic response is reduced by 20%~40%;when the structural dynamic analysis is studied,considering the radiation damping effect of infinite foundation is very necessary.The user element subroutine and wave input program could be extended to three-dimensional case easily,and offer a simple logical calculation method for the dynamic response analysis of analogous projects.

关 键 词：粘弹性边界单元 波动输入 地震分析 ABAQUS 厂房坝段 

分 类 号：TV642.4[水利工程—水利水电工程] P315.96[天文地球—地震学]