基于ABAQUS的三维粘弹性边界单元及地震动输入方法研究
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摘要
基于大型通用有限元软件ABAQUS,利用FORTRAN语言编写了适用于粘弹性人工边界的外源波动输入子程序SDAB.FOR.该子程序包含粘弹性边界和加载两部分,粘弹性边界通过子程序UEL结合隐式积分算法定义粘弹性边界单元对整个系统的雅克比矩阵贡献来实现;人工边界上的总波场分解为无局部场地效应影响的自由场与局部场地效应引起的散射场,地震波作用于人工边界的自由场荷载可由设计地震动位移时程和速度时程统一表达,利用描述法向荷载和切向荷载的加载子程序DSLOAD、UTRACLOAD实现,从而可方便实现地震动的有效输入,避免了单独求解自由场.将考虑粘弹性边界条件的外源波动输入和内源地震动输入方法分别应用于某高拱坝的动力响应分析,并与常规无质量地基模型计算结果进行了对比,结果表明,考虑地基辐射阻尼的两种地震动输入方法均会显著降低结构的动力响应,其中采用外源波动输入方法的降幅更大.
The external source wave input subroutine SDAB.FOR of viscoelastic artificial boundary is achieved by FORTRAN language based on the commercial FEM code ABAQUS.The subroutine includes two parts,the viscoelastic boundary and the loading.The viscoelastic boundary is carried out by subroutine UEL,in which Jacobian matrix contribution of the boundary is defined in form of implicit integral algorithm.The wave field at artificial boundary is separated into free field without local topography effect and scattering field induced by local topography effect.The free field of earthquake action at the artificial boundary is expressed generally by the design earthquake time histories of displacement and velocity,and is realized by the loading subroutines of DSLOAD and UTRACLOAD which describes the normal loads and tangential loads respectively.Thus the earthquake input is carried out effectively and the free field with solution separately is avoided.The external source wave input and the internal seismic motion input method with viscoelastic boundary conditions are applied to the dynamic analysis of a high arch dam respectively;and compared to the results of the massless foundation model.The results show that the two methods with the radiation damping of the foundation will reduce the structure's dynamic response obviously;and the decrease range of the external source wave input is more obvious.
The external source wave input subroutine SDAB.FOR of viscoelastic artificial boundary is achieved by FORTRAN language based on the commercial FEM code ABAQUS.The subroutine includes two parts,the viscoelastic boundary and the loading.The viscoelastic boundary is carried out by subroutine UEL,in which Jacobian matrix contribution of the boundary is defined in form of implicit integral algorithm.The wave field at artificial boundary is separated into free field without local topography effect and scattering field induced by local topography effect.The free field of earthquake action at the artificial boundary is expressed generally by the design earthquake time histories of displacement and velocity,and is realized by the loading subroutines of DSLOAD and UTRACLOAD which describes the normal loads and tangential loads respectively.Thus the earthquake input is carried out effectively and the free field with solution separately is avoided.The external source wave input and the internal seismic motion input method with viscoelastic boundary conditions are applied to the dynamic analysis of a high arch dam respectively;and compared to the results of the massless foundation model.The results show that the two methods with the radiation damping of the foundation will reduce the structure's dynamic response obviously;and the decrease range of the external source wave input is more obvious.
引文
[1]Lysmer J,Kulemeyer R L.Finite Dynamic Model forInfinite Media[J].Journal of Engineering Mechanics Di-vision,ASCE,1969,95(4):759-877.
[2]Deeks AJ,Randolph MF.Axisymmetric Ti me-domainTransmitting Boundaries[J].Journal of EngineeringMechanics Division,ASCE,1994,120(1):25-42.
[3]刘晶波,谷音,杜义欣.一致粘弹性人工边界及粘弹性边界单元[J].岩土工程学报,2006,28(9):1070-1075.
[4]杜修力,赵密,王进廷.近场波动模拟的一种应力人工边界[J].力学学报,2006,38(1):49-56.
[5]廖振鹏.工程波动理论导论[M].北京:科学出版社,2002.
[6]刘晶波,吕彦东.结构-地基动力相互作用问题分析的一种直接方法[J].土木工程学报,1998,31(3):55-64.
[7]赵建锋,杜修力,韩强等.外源波动问题数值模拟的一种实现方式[J].工程力学,2007,24(4):52-58.
[8]Abaqus Theory Manual(Version 6.7),Dassault Sys-tems Inc,2007.
[9]谷音,刘晶波,杜义欣.三维一致粘弹性人工边界及等效粘弹性边界单元[J].工程力学,2007,24(12):31-37.
[10]徐磊,叶志才,任青文等.基于ABAQUS的粘弹性动力人工边界精确自动施加[J].三峡大学学报:自然科学版,2010,32(1):20-23.
[11]陈厚群.坝址地震动输入机制探讨[J].水利学报,2006,37(12):1417-1423.
[12]李静,陈健云.动力相互作用分析中无质量地基的应用研究[J].世界地震工程,2007,23(2):58-62.
[13]Zhang Chuhan,Pan Jianwen,Wang Jinting.Influenceof seismic input mechanisms and radiation damping onarch dam response[J].Soil Dynamics and EarthquakeEngineering,2009,29(9):1282-1293.
[2]Deeks AJ,Randolph MF.Axisymmetric Ti me-domainTransmitting Boundaries[J].Journal of EngineeringMechanics Division,ASCE,1994,120(1):25-42.
[3]刘晶波,谷音,杜义欣.一致粘弹性人工边界及粘弹性边界单元[J].岩土工程学报,2006,28(9):1070-1075.
[4]杜修力,赵密,王进廷.近场波动模拟的一种应力人工边界[J].力学学报,2006,38(1):49-56.
[5]廖振鹏.工程波动理论导论[M].北京:科学出版社,2002.
[6]刘晶波,吕彦东.结构-地基动力相互作用问题分析的一种直接方法[J].土木工程学报,1998,31(3):55-64.
[7]赵建锋,杜修力,韩强等.外源波动问题数值模拟的一种实现方式[J].工程力学,2007,24(4):52-58.
[8]Abaqus Theory Manual(Version 6.7),Dassault Sys-tems Inc,2007.
[9]谷音,刘晶波,杜义欣.三维一致粘弹性人工边界及等效粘弹性边界单元[J].工程力学,2007,24(12):31-37.
[10]徐磊,叶志才,任青文等.基于ABAQUS的粘弹性动力人工边界精确自动施加[J].三峡大学学报:自然科学版,2010,32(1):20-23.
[11]陈厚群.坝址地震动输入机制探讨[J].水利学报,2006,37(12):1417-1423.
[12]李静,陈健云.动力相互作用分析中无质量地基的应用研究[J].世界地震工程,2007,23(2):58-62.
[13]Zhang Chuhan,Pan Jianwen,Wang Jinting.Influenceof seismic input mechanisms and radiation damping onarch dam response[J].Soil Dynamics and EarthquakeEngineering,2009,29(9):1282-1293.
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