Laser beam welding is a non-contact joining technique that has gained significant importance in the course of the increasing degree of automation in industrial manufacturing. This process has established itself as a suitable joining tool for metallic materials due to its non-contact processing, short cycle times, and small heat-affected zones. One potential problem, however, is the formation of solidification cracks, which particularly affects alloys with a pronounced melting range. Since solidification cracking is influenced by both temperature and strain rate, precise measurement technologies are of crucial importance. For this purpose, as an experimental setup, a Controlled Tensile Weldability (CTW) test combined with a local deformation measurement technique is used. The aim of the present work is the development of computational methods and software tools to numerically simulate the CTW. The numerical results are compared with those obtained from the experimental CTW. In this study, an austenitic stainless steel sheet is selected. A thermo-elastoplastic material behavior with temperature-dependent material parameters is assumed. The time-dependent problem is first discretized in time and then the resulting nonlinear problem is linearized with Newton's method. For the discretization in space, finite elements are used. In order to obtain a sufficiently accurate solution, a large number of finite elements has to be used. In each Newton step, this yields a large linear system of equations that has to be solved. Therefore, a highly parallel scalable solver framework, based on the software library PETSc, was used to solve this computationally challenging problem on a high-performance computing architecture. Finally, the experimental results and the numerical simulations are compared, showing to be qualitatively in good agreement.

翻译：激光束焊接是一种非接触式连接技术，随着工业制造自动化程度的不断提高，其重要性日益凸显。该工艺因其非接触加工、短周期时间和窄热影响区等特点，已成为金属材料适用的理想连接工具。然而，其潜在问题之一是凝固裂纹的形成，这对具有显著熔化温度区间的合金影响尤为突出。由于凝固裂纹受温度和应变速率双重因素影响，精确的测量技术至关重要。为此，本研究采用可控拉伸焊接性测试结合局部变形测量技术作为实验装置。本工作的核心目标是开发数值模拟CTW测试的计算方法与软件工具。数值计算结果与实验CTW测试结果进行了对比验证。本研究选用奥氏体不锈钢板材为对象，采用温度相关材料参数的热弹塑性本构模型描述材料行为。首先对瞬态问题进行时间离散化，随后采用牛顿法对所得非线性问题进行线性化处理。空间离散采用有限元方法。为获得足够精确的求解结果，必须使用大量有限单元网格。每个牛顿迭代步都会产生需要求解的大规模线性方程组。因此，基于PETSc软件库构建了高度并行化的可扩展求解框架，在高性能计算架构上求解这一计算密集型问题。最终，实验结果与数值模拟结果对比显示出良好的定性一致性。