The influence of constitutive material models on accumulated plastic strain in finite element weld analyses
The influence of constitutive material models on accumulated plastic strain in finite element weld analyses
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DOI：
10.1016/j.ijsolstr.2015.04.032
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发表时间：
2015-09-01
影响因子：
3.6
通讯作者：
Braham, C.
中科院分区：
文献类型：
--
作者：
Muransky, O.;Hamelin, C. J.;Braham, C.
计算焊接力学的最新研究揭示了材料塑性模型在预测焊接残余应力时的重要性。目前的工作试图扩展这一水平的理解，以包括假定的材料退火行为的影响，特别是在模拟由几个热机械加载循环组成的多道焊接时。采用经过验证的AISI316LN奥氏体钢三道缝焊接有限元模型，对不同材料模型预测的残余应力分布进行了一系列的数值分析。材料模型同时考虑了所选材料的加工硬化和退火假设。模型灵敏度不仅从焊接残余应力的角度建立，而且还从焊接件中累积的焊后塑性应变的评估中建立。将预测结果与使用从基准试件获得的交叉焊接显微硬度图获得的间接测量结果进行了比较。灵敏度研究表明，退火行为的选择将对塑性流动预测产生重大影响，这取决于指定的退火温度。退火假设将对焊接残余应力预测产生不同的影响，因此敏感程度取决于所选择的塑性模型。相反，塑性模型的选择对预测的焊接残余应力有显著影响，但对等效塑性应变的预测影响相对较小。皇冠版权所有(C)2015由爱思唯尔有限公司出版。保留所有权利。
Recent studies in computational weld mechanics have revealed the importance of the material plasticity model when predicting weld residual stresses. The present work seeks to extend this level of understanding to include the effects of the assumed material annealing behaviour, particularly when modelling multi-pass welds that comprise several thermo-mechanical loading cycles. A series of numerical analyses are performed to examine the variability in predicted residual stress profiles for different material models, using a validated finite element model for a three-pass slot weld in AISI 316LN austenitic steel. The material models consider both the work hardening and annealing assumptions for the chosen material. Model sensitivity is established not only from a weld residual stress perspective, but also from an assessment of the post-weld plastic strain accumulated in the weldment. Predictions are compared with indirect measurements acquired using cross-weld micro-hardness maps taken from benchmark specimens. Sensitivity studies reveal that the choice of annealing behaviour will have a significant impact on plastic flow predictions, which is dependent on the annealing temperature specified. Annealing assumptions will have a varying impact on the weld residual stress predictions, such that the extent of sensitivity is dependent on the plasticity model chosen. In contrast, the choice of plasticity model will have a significant effect on the predicted weld residual stresses, but relatively little effect on predictions of equivalent plastic strain. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.