Development of finite element code for assessing large deformation problems with ALE

开发用于使用 ALE 评估大变形问题的有限元代码

基本信息

批准号：
09650550
负责人：
MIMURA Mamoru
金额：
$ 0.32万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650550/
关键词：
ALE Finite Element Method CPT Localization of Deformation Stress Concentration Plastic Shear Strain Large Deformation Problem Finite Strain

项目摘要

CPT is widely used for subsoil investigation. However, the mechanism of penetration process has not rationally been explained because this problem is one of the most difficult boundary value problems with large deformation around cone. Eulerean finite element method has successfully been applied to the analysis of the process of cone penetration. The problem with respect to the element distortion can be avoided if the material displacement increments are uncoupled from the grid point displacement increments. Performance in clay as well as sand deposits is discussed. Undrained analysis was used for clay based on the fact that the process of penetration in clay deposits can be considered as a phenomenon under perfectly undrained condition. In-situ CPT at Kinkai Bay site was selected to validate the calculated performance for CPT in clay deposit. On the other hand Higashi Ogishima reclaimed sand deposit and Kemigawa Pleistocene sand deposit are selected as representatives for sandy deposits. Far from the case of clay deposit, fully drained condition is satisfied for the process of penetration in sandy deposit. Dilatancy effect is also introduced into the numerical assessment. For both clay and sand deposits, the calculated performance can describe the in-situ cone tip resistance well, and shows the significant stress build-up and large strain around cone due to penetration. Furthermore, even in the frictional materials such as sand, the affected area in terms of plastic deformation is found to be localized in the vicinity of cone shaft.

CPT广泛用于地下土壤研究。但是，渗透过程的机制尚未合理解释，因为此问题是圆锥周围大变形的最困难的边界价值问题之一。 Eulerean有限元方法已成功应用于锥体穿透过程的分析。如果材料位移增量与网格点位移增量取消相关，则可以避免相对于元素失真的问题。讨论了粘土和沙子沉积物的性能。基于以下事实，将未排水的分析用于粘土，即在完全不排水的条件下，粘土沉积物中的渗透过程可以视为一种现象。选择Kinkai Bay站点的原位CPT来验证CPT在粘土沉积中的计算性能。另一方面，Higashi Ogishima回收的沙子沉积物和Kemigawa更新世砂沉积物被选为沙质沉积物的代表。远离粘土沉积的情况，满足了在沙质沉积物中穿透过程的完全排水状态。膨胀效应还引入了数值评估中。对于粘土和沙子沉积物，计算出的性能可以很好地描述原位锥尖端的电阻，并显示出由于穿透而周围的巨大应力堆积和较大的应变。此外，即使在诸如沙子之类的摩擦材料中，就塑料变形而言，受影响区域也位于锥形轴附近。