Evaluation of Damaged state of Metallic Materials with Microsturctures in terms of Tesellation Analysis

基于曲面细分分析的金属材料微观结构损伤状态评估

基本信息

批准号：
07650103
负责人：
NAGAKI Shigeru
金额：
$ 1.54万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650103/
关键词：
Damage Mechanics Microstructure Tessellation Voronoi Polrygon Plastic Anisotropy Damage Tensor Perforated Sheet

项目摘要

In plastic deformation of damaged materials, the influence of distribution of voids on macroscopic mechanical properites is an important issue. In this research project, it is our purpose to establish a new method in order to evaluate the damaged state of metalic materials with voids. We proposed a method using voronoi tessellation and stereology, where the material region is divided into many voronoi polygons in which only one void is inclueded. This method provides the representative unit cell for the specific region including polygons with a hole so that the damage tensor components can easily be calculated. Tensile tests of several kinds of perforated specimens were carried out and experimental results indicated that the fracture pattern was well estimated by the normal component of the damage tensor to the loading direction. It is also shown that the deformation of each hole is closely correlated with the damage tensor. For ductile fracture of materials, as it is well known that the existence of damage due to voids and its configuration play the important role qualitatively, it is necessary to clarify the quantitative evaluation of damage by taking account of not only the volume fraction of voids but the spatial configuration of voids. The theory presented here may provide the simple method to evaluate the damage state quantitatively. Further investigations are required to the evaluation of damage growth sue to deformation of voids in the 3 dimensional space.

在损坏材料的塑性变形中，空隙分布对宏观机械适当矿物的影响是一个重要问题。在该研究项目中，我们的目的是建立一种新方法，以评估具有空隙的金属材料状态。我们提出了一种使用Voronoi Tessellation和立体学的方法，其中材料区域分为许多Voronoi多边形，其中仅包含一个空隙。该方法为特定区域提供了代表性的单位单元，包括带有孔的多边形，以便可以轻松计算损伤张量组件。进行了几种穿孔样品的拉伸试验，实验结果表明，骨折模式通过损伤张量的正常成分与载荷方向进行了很好的估计。还表明，每个孔的变形与损伤张量密切相关。对于材料的延性裂缝，众所周知，由于空隙及其构型的损害存在质量上的重要作用，因此有必要通过不仅考虑空隙的空间构型的体积分数来阐明损害的定量评估。这里提出的理论可以提供简单的方法来定量评估损伤状态。需要进一步研究以评估损伤生长起诉到3维空间中空隙变形的变形。