摘要
为高效高精度地预测大尺寸结构FSW焊接变形,基于考虑夹具接触约束的热弹塑性仿真结果,在分析塑性应变的区域分布特点的基础上运用固有应变法进行分区映射,发展了一种有效的焊接变形预测方法。针对小尺寸6061-T6铝合金板材FSW焊接,将接触约束状态和固定约束状态下的焊后变形预测值与实验值进行了对比分析,结果表明接触约束状态的预测结果更接近实际的非对称变形。将该方法应用于大尺寸6061-T6铝合金板材焊接,并将所得结果与大尺寸板材接触约束状态下热弹塑性法结果进行对比,结果表明,该方法可有效地预测大尺寸板材搅拌摩擦焊接变形。
In this paper, an effective prediction method is proposed to predict the FSW weld deformation for the large-size structures using partition mapping of inherent strain under the local-global mapping frame. The contact state between fixtures and weldment is considered by contact constraints in the thermoelastic-plastic simulation of local structure. The detailed partition scheme is determined by the distribution characteristics of residual plastic strain on the basis of the prediction results of local structure, and the partition scheme is implemented to the global structure for the partition mapping of inherent strain. For the welding of small-size 6061-T6 aluminum alloy sheet, the weld deformations are predicted under the contact and fixed constraint states by thermoelastic-plastic simulation, and these results are analyzed and compared with the experimental data. The results show that the prediction results considering contact constraints are closer to the experimental data and can capture actual asymmetric deformation, thus it is necessary that the contact constraints between fixtures and weldment are modeled in the local structure. The proposed method is applied to the welding of large-size 6061-T6 aluminum alloy plates, and the prediction results are compared with those obtained by thermoelastic-plastic method considering the contact constraints between fixtures and weldment. The results show that the proposed method can effectively predict the welding FSW deformation of large-size plates.
作者
常天根
高月华
刘其鹏
CHANG Tiangen;GAO Yuehua;LIU Qipeng(School of Locomotive and Vehicle Engineering,Dalian Jiaotong University,Dalian 116028,China;School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,China)
出处
《电焊机》
2022年第2期17-25,共9页
Electric Welding Machine
基金
辽宁省自然科学基金(20170540120)。
关键词
搅拌摩擦焊
固有应变
分区映射
接触约束
焊接变形
friction stir welding
inherent strain
partition mapping
contact constraint
welding deformation
