Investigation of the Stress-Focusing Effect and Determination of Stress Focusing Intensity Factor

应力集中效应的研究及应力集中强度因子的确定

基本信息

批准号：
07650096
负责人：
HATA Toshiaki
金额：
$ 1.54万
依托单位：
SHIZUOKA 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 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650096/
关键词：
Thermal Stresses Thermal Shock Stress Focusing Elasticity Stress Waves Stress Focusing Intensity Factors 弾性波波線法波絆法

项目摘要

The stress-focusing effect is the phenomenon that, under an instantaneous heating, stress waves reflected from the free surface of the sphere or the cylinder result in very high stresses at the center, even though the initial thermal stress is relatively small. This plenomenon may be observed in the solid spheres subjected to the spherical symmetric heating and in the solid cylinders subjected to the cylindrical symmetric feating. This type of heating may be caused by the absorption of electromagnetic radiant energy or laser rays.This paper reviews recent extensions of the analytical methods for the problem of thermal shock in spheres and cylinders, especially, for the problem of thermal stress-focusing effect in spheres and cylinders. First, considering the problem of thermal shock in a hollow sphere subjected to the rapid uniform heating, if the ratio of the outer radius to the inner radius of the sphere increases, the peak tangential stress at the internal surface becomes higher and higher. As a limit case, for a solid sphere, it might be possible to observe the stress-focusing effect.Next, as for the analysis of a long cylindrical rod due to the instantaneous heating, stress waves also show the stress-focusing effect. While the method of ray theory is effective in the analysis of stress-focusing effect in a sphere, the method of ray series is effective in the analysis of stress-focusing effect in a cylinder. Therefore, the major accomplishment of this study has been in gaining a better understanding of the stress-focusing effect in the solid spheres and long cylindrical rods.In this study, analyzing the behavior of the stress focusing effect in a sphere, we introduce the stress focusing intensity factor S_<Fi>, which is expressed by the relation sigma_i=S_<Fi>/r^3 (i=r, rheta, phi) at the focusing points. This factor denotes the strength of stress focusing.

应力的效应是一种现象，即在瞬时加热下，从球体的自由表面反射的应力波或圆柱体会导致中心的应力很高，即使最初的热应力相对较小。可以在经受球形对称加热的固体球体和经受圆柱对称性壮科的固体圆柱体中观察到这种全体类动物。这种加热可能是由于电磁辐射能或激光射线的吸收引起的。本文回顾了球体和圆柱体中热休克问题的分析方法的最新扩展，尤其是对于球形和cy剂中热应力效应的问题。首先，考虑到经受快速均匀加热的空心球的热冲击问题，如果外半径与球体内半径的比率增加，则内表面的峰值切向应力越来越高。作为一个极限情况，对于实体球体，可能会观察到应力的效果。对于由于瞬时加热而对长圆柱杆的分析，应力波还显示了应力的效应。尽管射线理论方法在球体中的应激效果分析有效，但射线系列方法可有效地分析圆柱体中的应激作用。因此，这项研究的主要完成是在更好地了解固体球和长圆柱杆中的应激效果。在这项研究中，分析了球体中压力聚焦效应的行为，我们介绍了压力聚焦强度因子s_ <fi>，通过关系sigma_i = s_ = s_ <fi>/r^3（i = r^3（i = r^3（r），这是由关系表达的。该因素表示压力集中的强度。