Empirical Dynamic Modeling of Friction Stir Welding Processes
Empirical Dynamic Modeling of Friction Stir Welding Processes
复制标题
搅拌摩擦焊接过程的经验动态建模
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
K. Krishnamurthy
中科院分区：
文献类型：
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作者：
Xin Zhao;Prabhanjana Kalya;R. Landers;K. Krishnamurthy
当前的搅拌摩擦焊(FSW)过程建模研究主要涉及对材料流动、发热等局部影响的详细分析。这些详细的热力学模型通常使用有限元或有限差分格式求解，需要大量的计算工作来确定单个时间点或非常短的时间范围内的温度、力等。为了设计反馈控制策略和改进工艺规划和分析，需要描述整个焊接过程中作用在工具上的总力的动态模型。本文建立了过程参数(如沉入深度、行程速度和转速)与过程变量(如轴向力、径向力和法向力)之间的经验模型，以了解它们之间的动态关系。首先，建立工艺参数与工艺变量之间的稳态关系，确定各工艺参数对各工艺变量的相对重要性。然后，利用递推最小二乘法确定过程变量的动态特性。结果表明，过程参数与过程变量之间的稳态关系符合非线性幂关系，动态响应符合低阶线性方程。通过实验对所建立的搅拌摩擦动力学模型进行了验证。
Current friction stir welding (FSW) process modeling research is mainly concerned with the detailed analysis of local effects such as material flow, heat generation, etc. These detailed thermomechanical models are typically solved using finite element or finite difference schemes and require substantial computational effort to determine temperature, forces, etc., at a single point in time, or for a very short time range. Dynamic models describing the total forces acting on the tool throughout the entire welding process are required for the design of feedback control strategies and improved process planning and analysis. In this paper, empirical models relating the process parameters (i.e., plunge depth, travel speed, and rotation speed) to the process variables (i.e., axial, path, and normal forces) are developed to understand their dynamic relationships. First, the steady-state relationships between the process parameters and the process variables are constructed, and the relative importance of each process parameter on each process variable is determined. Next, the dynamic characteristics of the process variables are determined using recursive least-squares. The results indicate the steady-state relationship between the process parameters and the process variables is well characterized by a nonlinear power relationship, and the dynamic responses are well characterized by low-order linear equations. Experiments are conducted that validate the developed FSW dynamic models.