The Residual Stress Research of Rolling Slab Based on the No-Linear Elastic and Plastic Analysis

2011 ◽  
Vol 311-313 ◽  
pp. 1093-1096
Author(s):  
Zhao Wei Dong ◽  
Xiao Hang Wan ◽  
Shu Jun Li ◽  
Sheng Yong Liu

The cold rolling of slab is analyzed by using elastic-plastic and heat-mechanic coupling FEM with the nonlinear method. The distribution of residual stress was analyzed mainly in this paper. It is indicated by the results that the residual stress in surface layer of slab material is the pressure stress and inside the plate is the tension stress under the smaller press quantity, the residual stress in surface layer is the tension stress and inside the slab is the pressure stress under bigger press quantity, the maximum residual tension stress in the slab becomes bigger with the increment of the reduction.

2000 ◽  
Vol 35 (2) ◽  
pp. 137-142 ◽  
Author(s):  
H Jahed ◽  
S B Lambert ◽  
R N Dubey

Based on a general axisymmetric method of elastic-plastic analysis presented by Jahed and Dubey, elastic-plastic boundaries and residual stress fields induced by cold expansion of fastener holes is predicted. The method uses a linear elastic solution to construct an elastic-plastic solution. The material parameters are treated as field variables and their spatial distributions are obtained as part of the solution. This method uses the actual loading-unloading behaviour of the material and therefore is capable of predicting an accurate residual stress field. Results obtained here are compared with available experimental and finite element results. The agreement of the results with experimental measurements is very good. It is shown that employment of the actual unloading material curve can make a significant change in residual field prediction.


1983 ◽  
Vol 14 (11) ◽  
pp. 2415-2421 ◽  
Author(s):  
Y. Yokouchi ◽  
T. W. Chou ◽  
I. G. Greenfield

Author(s):  
Akira Maekawa ◽  
Atsushi Kawahara ◽  
Hisashi Serizawa ◽  
Hidekazu Murakawa

Residual stress caused by welding processes affects characteristics of strength and fracture of equipment and piping in power plants. Numerical thermal elastic-plastic analysis is a powerful tool to evaluate weld residual stress in actual plants. However, the conventional three-dimensional precise analysis for a welding process such as multi-pass welding, machining and thermal treatment requires enormous computation time though it can provide accurate results. In this paper, the finite element analysis code based on the iterative substructure method that was developed to carry out thermal elastic-plastic analysis efficiently, with both high computational speed and accuracy, was proposed to simulate the welding process of plant equipment and piping. Furthermore, optimization of the proposed analysis code was examined and the computational efficiency and accuracy were also evaluated.


Author(s):  
Igor Orynyak ◽  
Andrii Oryniak

The development of powerful commercial computer programs made the concept of J-integral as computational parameter of fracture mechanics to be a very attractive one. It is equivalent to SIF in linear case, it converges in numerical calculation and the same results are obtained by different codes (programs). Besides, it is widely thought that elastic-plastic analysis gives bigger values than elastic SIF ones what is good from regulatory point of view. Such stand was reflected in the recommended by IAEA TECDOC 1627 (February 2010) devoted to pressurized thermal shock analysis of reactor pressure vessels, where the embedded crack in FEM mesh, elastic-plastic analysis with simultaneous determination of J-integral was stated as the best option of analysis. But at that time all the most widely used software were not able to treat the residual stresses, the thermal stresses in case of two different materials. Such a contradiction between requirements and the possibilities made a lot of problems for honest contractors especially in countries where the regulator had no own experience in calculation and completely relied on the authority of international documents. This means that at that time the said recommendations were harmful. The main reason of such a situation was the absence of the carefully elaborated examples. Now the capabilities and accuracy of such software are increasing. Nevertheless, some principal ambiguities and divergences of computations results in various J-integral contours around the crack tip still exist. They are exhibited when the large plastic zone emerges at the crack tip. Other problem is influence of the history of loading and the specification of the time of crack insertion in the mesh including the time of emergence of residual stress. This paper is invitation for discussion of the accuracy and restriction of computational J-integral. With this aim the detailed analysis of some simplified 2D examples of calculation of elastic -plastic J-integral for surface crack with accounting for residual stress, thermal stress and inner pressure are performed and commented. The attainment of consensus among the engineering society for treating the outcome results is the prerequisite for practical application of computational elastic plastic J-integral.


2002 ◽  
Vol 2002.2 (0) ◽  
pp. 497-498
Author(s):  
Yasushi IMABAYASHI ◽  
Chu SAKAE ◽  
Masanobu KUBOTA ◽  
Yoshiyuki KONDO

Author(s):  
R. Adibi-Asl ◽  
W. Reinhardt

This paper presents a robust non-cyclic method to identify the boundary between the shakedown and ratcheting domains (ratchet boundary) directly without the need for cyclic analysis. The solution can be obtained using only linear-elastic FEA. The method is based on lower bound formulation in shakedown theory, which is safe for design. It offers an attractive alternative to cyclic elastic-plastic analysis since it is simple, and requires considerably less computational effort and computer storage space. Another attractive feature is that the method provides a go/no go criterion for the ratchet boundary, whereas the results of a cyclic elastic-plastic analysis are often difficult to interpret near the ratchet boundary. The proposed method is applied to a number of configurations that include two-dimensional and three-dimensional effects.


Sign in / Sign up

Export Citation Format

Share Document