基于实体退化单元的高墩非线性稳定仿真分析  

Simulation analysis of nonlinear stability of high pier based on degenerated solid element

作　　者：牛辉[1] 汪劲丰[1] 张巍[1] 俞亚南[1] 吴光宇[2] 

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058 [2]南昌大学建筑工程学院,江西南昌330031

出　　处：《浙江大学学报（工学版）》2012年第6期1082-1089,共8页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51108411);浙江省自然科学基金资助项目(Y1110181)

摘　　要：为克服在薄壁空心高墩的非线性分析中解析法不便应用、杆系有限元法不能模拟钢筋、实体单元法计算效率较低等不足,以及为提高计算效率且不降低模拟精度,提出采用实体退化单元的方法进行非线性稳定分析.在该方法中,用三维实体退化单元模拟薄壁空心高墩,运用单元分块技术实现钢筋单元的模拟,基于多尺度分析思想建立精确模型进行非线性稳定分析;阐述几何非线性、材料非线性及方程求解方法,讨论了稳定分析的实现方式.采用此方法对一数值模型进行第一类及第二类稳定性分析,并与传统的实体单元模型进行对比证明了该方法在非线性稳定分析中的有效性.并将此方法应用于工程实例,结果表明:该方法能真实有效地模拟实际结构,客观地反映钢筋对墩体稳定性的影响,高效地进行非线性分析;适用于对需要考虑钢筋影响的结构及对薄壁空心高墩结构型式进行非线性稳定分析.Among the methods for the nonlinear stability analysis of hollow thin-walled high pier,analytical methods have the defects of the narrow scope of application,the trouble in coping with complex structures and difficulty in practice,and conventional bar system finite element method（FEM） could simulate a structure in small scale and complete calculation efficiently but being incapable in modeling reinforcements,while solid element method have merit in precisely modeling structures but being inefficient in calculation or even unable to converge.Therefore,for improving calculating efficiency without reducing simulation accuracy,a nonlinear stability analysis method,using the degenerated solid element,was proposed.Implementing this method,high piers were modeled by using 3D degenerated solid element and reinforcements simulated by employing blocking integral technique,the nonlinear stability analysis was carried out by establishing the accurate finite element model based on multi-scale analysis theory.Key issues,such as geometric nonlinearity,material nonlinearity and numeric algorithm were set forth to discuss the fulfillment of the stability analysis of high piers.A numerical example,compared with conventional solid element in first and second stability analysis,was used to prove the method＇s validity in nonlinear analysis.And the stability analyzing of an actual structure was fulfilled by this method.The result shows that the method discussed above can objectively model the structure＇s geometric characters,defining material properties of concrete and rebars,assess the effect of reinforcements,and carry out the nonlinear analysis efficiently.It can be used in nonlinear stability analysis of structures that should not neglect the influence of reinforcements and of hollow thin-walled high piers.

关 键 词：高墩稳定性 非线性分析 有限元分析 实体退化单元 钢筋模型 

分 类 号：TU443.22[建筑科学—岩土工程]