权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of methods for prediction and control of welding stress and deformation besed on concept of inherent strain as their essential source

开发基于固有应变概念作为其基本来源的焊接应力和变形的预测和控制方法

基本信息

批准号：
03302037
负责人：
UEDA Yukio
金额：
$ 4.29万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Co-operative Research (A)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

To promote the automation of shipbuilding process, the prediction and the control of the welding deformation are very important problems to be solved. Also, to achieve highly reliable estimation of the safety of ships against the fatigue damage, the quantitative estimation of welding residual stress is necessary. For establishing a consistent view on the welding residual stress and the deformation, the problem should be examined on the bases of the concept of inherent strain, which is considered to be the source of both the residual stress and the deformation. For the quantitative comparison to identify the most influential factor, numerical methods such as the FEM is a very powerful tool.Thus, a FEM code was developed in the first year of this research program for the prediction and the control of the welding deformation. The characteristics of the inherent strain and the residual stress were clarified. Further, the effects of tack welding pitch and the type of tab-plate are investigated based on the FEM simulation.In the following two years, the effects of root gap due to the cutting error and the residual stress in the steel plate are examined. Through this study, it is found that these factors are more influential than the tack weld and the tab. Thus, it is necessary to control them to reduce the welding deformation.To estimate the residual stress in butt weld and fillet weld with small number of measuring points, a new measuring method was developed and its validity was examined through experiments. The proposed method is based on the concept of inherent strain and the fact that the distribution of the inherent strain can be accurately described as a function involving small number of parameters.

为了促进造船过程的自动化，焊接变形的预测和控制是一个亟待解决的重要问题。此外，为了实现对船舶抗疲劳损伤的安全性的高度可靠的估计，焊接残余应力的定量估计是必要的。为了对焊接残余应力和变形问题有一个统一的认识，必须从固有应变的概念出发，认为固有应变是焊接残余应力和变形的根源。为了进行定量比较以确定最大的影响因素，数值方法如有限元法是一个非常强大的工具。因此，在本研究计划的第一年，开发了一个有限元程序，用于预测和控制焊接变形。阐明了固有应变和残余应力的特点。在此基础上，通过有限元模拟研究了定位焊节距和定位板类型对定位结果的影响，并在随后的两年时间里研究了由于切割误差引起的根部间隙和钢板中的残余应力对定位结果的影响。通过本研究发现，这些因素的影响比定位焊和调整片更大。为了在少量测点的情况下测量对接焊和角焊的残余应力，提出了一种新的测量方法，并通过实验验证了该方法的有效性。所提出的方法是基于固有应变的概念和事实，即固有应变的分布可以准确地描述为一个函数，涉及少量的参数。