Semi-static modeling of laser utilization in thermal forming simulations

利用激光诱导塑性变形是一种既能成形简单弯曲零件，又能成形复杂几何形状的灵活方法。这种效果甚至可以用在生产过程链中，作为附加的补偿中间步骤，以最大限度地减少由制造步骤引起的变形。形状的较大变化主要是通过沿弯曲边缘的多次照射循环(增量过程)来实现的。有限元方法等数值计算方法非常灵活，可以模拟弯曲过程。然而，传统的有限元模拟依赖于局部瞬时加热的过程被证明在计算时间方面是非常昂贵的，因此对于工艺规划往往是不可行的。到目前为止，为加快模拟而采取的方法代表了对有限范围的工艺参数的具体解决办法，不能自由转让。通过实施半静态热负荷步骤，给出了暂态局部加热的近似表示。这是一种非常有效的方法，几乎没有人从力学材料响应的角度对其进行研究。很可能，这种特别用于大量辐射的近似策略甚至会导致几个小数次方的时间优势。因此，拟议项目的目标是以激光弯曲为例进行半静态加热的适应，并评估其有效性的边界。

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.