Semi-static modeling of laser utilization in thermal forming simulations

利用激光束诱导塑性变形是一种灵活的方法，可以形成简单的弯曲零件以及复杂的几何形状。这种效应甚至可以在生产过程链中用作附加的补偿步骤，以最小化由制造步骤引起的失真。大多数情况下，通过沿弯曲边缘沿着多次辐照循环（增量过程），可实现形状的较大变化。数值计算方法如有限元法（FEM）对于模拟弯曲过程是足够灵活的。然而，传统的使用有限元法来模拟依赖于瞬态局部加热的过程证明了其本身在计算时间方面是非常昂贵的，因此对于工艺规划来说通常是不切实际的。到目前为止，采取的方法，使模拟更快地代表特定的解决方案，有限的工艺参数范围内，不能自由转让。瞬态局部加热的近似表示是通过半静态加热负载步骤的实施来提供的。这是一种非常有效的方法，几乎没有在机械材料响应方面进行过研究。很可能，特别是在大量辐照下使用的这种近似策略甚至会导致几个十进制幂的时间优势。因此，拟议项目的目标是在激光束弯曲的例子中进行半静态加热的调整，并评估其有效性的界限。

The induction of plastic form changes by the utilization of the laser beam is a flexible method to form simple bended parts as well as complex geometries. This effect may be even used in chains of production processes as an additional compensating interim-step to minimize the distortion resulting from the manufacturing steps. Large changes to the form are mostly reached by a multiple number of irradiation cycles along the bending edge (incremental process). Numeric calculation methods like the finite element method (FEM) are sufficiently flexible to simulate the bending process. However, the conventional use of the FEM to simulate processes relying on transient local heating proves itself to be extraordinarily costly in terms of calculation time and therefore often impracticable for process planning. So far undertaken approaches to make the simulation faster represent specific solutions for a limited range of process parameters and are not freely transferable. An approximate representation to the transient local heating is provided by the implementation of a semi-static heating load step. It is a very efficient approach, which has barely been researched in terms of the mechanical material response. It is likely, that such approximation strategy particularly used on large numbers of irradiations will even result in a time advantage of several decimal powers. Therefore, the goal of the proposed project is to undertake an adaption of the semi-static heating at the example of the laser beam bending and to assess the boundaries of its effectiveness.