模拟搅拌摩擦焊的FEM-SPH耦合法研究

项目名称： 模拟搅拌摩擦焊的FEM-SPH耦合法研究

项目编号： No.11302077

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 肖毅华

作者单位： 华东交通大学

项目金额： 23万元

中文摘要： 搅拌摩擦焊（FSW）是一项在轻合金焊接方面极具优势的技术。数值模拟可以为FSW焊接工艺参数的优化提供指导，同时有助于人们加深对FSW焊接机理的理解，更好地应用和发展该技术。传统的数值方法在模拟FSW时都存在一定困难，并且在计算效率上面临巨大的挑战。本项目通过构建求解热力耦合问题的高精度SPH格式，开发相关的热力边界处理技术，发展FEM与SPH的接触界面和耦合界面计算技术，嵌入合理的本构模型、接触摩擦模型，建立一套能有效模拟FSW焊接过程的FEM-SPH耦合法，克服传统数值方法存在的网格畸变、物质界面难于追踪等困难。在此基础上，利用基于图形处理器(GPU)的并行计算技术，开发GPU加速的FEM-SPH耦合法及程序，大大提高计算效率，降低FSW模拟的计算时间成本，从而为FSW的研究和应用提供一种新的有力的数值分析工具。

中文关键词： 搅拌摩擦焊；有限元法；光滑粒子流体动力学；无网格对称粒子法；耦合

英文摘要： Friction stir welding (FSW) is a very good technique for the welding of light metal. Numerical simulation can provide guidelines to determine optimal process parameters for FSW welding. It can also promote the understanding of welding mechanism and be helpful to use and develop the technique better. For FSW simulation, traditional numerical methods have some difficulties and suffer from great challenge in computational efficiency. In this project, SPH formulation of high accuracy for thermo-mechanical problem is established and relevant techniques for imposing thermal, and mechanical boundary conditions are developed. Algorithms for handling contact and coupling interfaces between FEM and SPH are proposed. Reasonable constitutive model and friction model are also incorporated. Through the aforementioned work, an effective FEM-SPH coupling method is constructed for FSW simulation. It overcomes the deficiencies of traditional methods, such as mesh tangling, difficult to capture material interfaces and so on. With GPU-based parallel computing technique, a GPU-accelerated FEM-SPH coupling method is developed, which improves the computational efficiency significantly and lowers the time cost for FSW simulation. The GPU-accelerated FEM-SPH coupling method can provide a new powerful numerical tool for the investigation

英文关键词： Friction stir welding；Finite element method；Smoothed particle hydrodynamics；Meshless symmetric particle method；Coupling