Splitting type wood cutting with wedge-shaped knife by stress field control.

通过应力场控制，使用楔形刀进行劈开式木材切割。

基本信息

批准号：
63560158
负责人：
OHTA Masamitsu
金额：
$ 1.41万
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：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

The aim of this research is to investigate the possibility of a splitting type wood cutting with wedge-shaped knife, in the case where the direction of knife's movement dose not coincide with the fiber angle, by controlling the stress field around the knife tip. This method has many improvements, when compared with ordinary saw cutting, such that it will produce no sawdust and be almost noiseless. In the experiments, we used spruce wood, and wedge shaped knife with tip angle 20 degrees, thickness 3 mm. To charge lateral load on the specimens at any angles, hydraulic type loading equipment was made. The following are our conclusion:1. When the whole lateral surface of the specimen was pressed, with adequate pressure, expected type cutting was possible. The amount of the load was more important than the direction of the load on controlling the quality of the cut specimen. In the simulation of stress field by a non-linear finite element method, an index proposed by Tsai & Wu could explain rather good the experimental results. 2. By a partial lateral compression, we could not get good result and confirmed this fact by a finite element analysis. 3. As it was difficult to predict the direction of crack propagation at a knife tip, we were forced to investigate criteria driven from the anisotropic plastic theory.In practical machine, it would not be necessary to change the lateral force angle synchronized with the grain angle, but if it employs partial compression system using caterpillars or other equipments, sufficiently large compression area would be required to reduce the cracks. In this system, there exist rather large plastic deformation around the knife tip, and then it would be indispensable to use very thin knife.

这项研究的目的是研究用楔形刀切割型木材切割的可能性，如果刀的运动剂量的方向通过控制刀尖周围的应力场而与纤维角不一致。与普通的锯切相比，该方法有许多改进，因此它不会产生木屑，几乎没有嘈杂。在实验中，我们使用了云杉木头和楔形刀，尖端角度为20度，厚度为3毫米。为了以任何角度在样品上充电，制作了液压式装载设备。以下是我们的结论：1。当标本的整个横向表面以足够的压力按下时，预期的类型切割就可能了。负载的量比控制切割样品的质量的负载方向更重要。在通过非线性有限元方法对应力场的仿真中，Tsai＆Wu提出的指数可以很好地解释实验结果。 2。通过部分横向压缩，我们无法获得良好的结果，并通过有限元分析确认了这一事实。 3。由于很难预测刀尖处的裂纹繁殖方向，因此我们被迫调查从各向异性塑料理论中驱动的标准。在实用机器中，不需要改变与晶状角度同步的横向力角，但如果它使用caterpillars使用部分压缩系统，则需要大量的压缩区域，以减少裂缝或其他要求。在该系统中，刀尖周围存在相当大的塑性变形，然后使用非常薄的刀是必不可少的。