Analysis of the fracture process of wood by Modified Distinct Element Method.

改进离散元法分析木材断裂过程。

基本信息

批准号：
06660204
负责人：
OHTA Masamitsu
金额：
$ 1.22万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660204/
关键词：
Distinct Element Method fracture process crack propagation anisotropy wood cutting simulation

项目摘要

This year, using a Modified Distinct Element Method for wood, which was developed last year, simulations on wood fracturing processes, especially on wood cutting, were made and analyzed results were compared with the experimental ones. First simulation object was the second-dimensional wood cutting, which gave different results of chip formation between longitudinal cutting and lateral cutting. The advanced checking in logitudinal cutting was well simulated, but the chip curling process of lateral cutting could not be realized. This inconvenience became from the fact that the program was apt to diverge in large calculating steps and then the simulation of large deformation was difficult. Second simulation object was the effect of the cutting velocity on the cut surfaces. The comparison with the experimental results used cantilever shaped model specimens gave good accordance to the MDEM simulation results. This year, a little improvement was done to the calculating program. Now I can obtain stress distribution in the specimen, and by this, I showed that MEDM could be used similary as a Finite Element Method. Further more, by analyzing the forces acting on the element springs, I found that we can simulate the cutting forces also.These results were presented at the International Wood Machining Seminar (Oct.1995, Kyoto) and received good response.

今年，使用了去年开发的木材修改的不同元素方法，对木材破裂过程进行了模拟，尤其是在木材切割方面，进行了分析，并将结果与实验性的结果进行了比较。第一个模拟物体是二维木切割，在纵向切割和侧向切割之间产生了不同的芯片形成结果。逻辑切割中的高级检查进行了充分的模拟，但是无法实现横向切割的芯片卷发过程。这种不便是由于该程序易于在大型计算步骤中发散，然后很难模拟大变形。第二个模拟对象是切割速度对切割表面的影响。与使用悬臂形模型样品的实验结果的比较给出了MDEM仿真结果的良好性。今年，计算计划做出了一些改进。现在，我可以在样品中获得应力分布，因此，我表明MEDM可以用作有限元方法。此外，通过分析作用在元素弹簧上的力，我发现我们也可以模拟切割力。这些结果是在国际木材加工研讨会（1995年10月，京都）上提出的，并得到了良好的反应。