FEM MODEL OF BIOTS EQUATION FREE FROM VOLUME LOCKING AND HOURGLASS INSTABILITY
A finite element modeling for liquefaction analysis that is free from volume locking and hourglass instability is proposed. Volume locking occurs when no or very small volume change is expected, which occurs under undrained condition or similar in liquefaction analysis, because bulk modulus of water is much larger than that of soil skeleton and volume of porewater hardly changes. On the other hand, hourglass instability occurs under excess reduced integration which is used to avoid volume locking. Proposed finite element formulation is based on so called u-U formulation, and different numerical integration schemes are employed for porewater and soil skeleton: ordinary integration for soil skeleton and reduced integration for all other element matrices.Numerical examples are made to evaluate effectiveness and accuracy of the proposed method by comparing other existing methods. The proposed method is shown to be accurate and also it is free from both volume locking and hourglass instability.
liquefaction effective stress analysis volume locking hourglass instability finite element
Y.Ohya N.Yoshida
PhD Student,Dept.of Civil and Environmental Engineering,Tohoku Gakuin University,Tagajyo.Japan Professor,Dept.of Civil and Environmental Engineering,Tohoku Gakuin University,Tagajyo.Japan
国际会议
14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)
北京
英文
2008-10-12（万方平台首次上网日期，不代表论文的发表时间）