Modelling of broaching processes by multi scale discretisation

在拉削中，工艺过程参数直接在刀具中磨削，因此必须在设计阶段定义。必须根据刀具和工件材料的组合来决定齿距、每齿齿高以及齿的宏观和微观几何形状。这些设计参数显着影响生产率、切屑形成、刀具磨损和切削力，并且实验优化非常昂贵。因此，拉刀大多采用故障安全设计，即使根据热机械刀具负载、机床和工件要求设计并不是最佳的。该项目的目标是开发多尺度模型来模拟拉削过程。该方法旨在显示和计算流程、工具和机床之间的相关交互。因此，可以在刀具负载、生产率和制造成本方面有效地设计拉刀和工艺。该模型由多个子模型组成，用于在不同的空间和时间尺度上离散拉削过程。这使得将介观切屑形成模型的精度与宏观过程和机器模型相结合成为可能。

In broaching, the technological process parameters are directly ground in the tool and therefore have to be defined in the design stage. Decisions about the tooth pitch, the rise per tooth and the tooth macro- and microgeometry have to be made according to the tool and workpiece material combination. These design parameters significantly influence the productivity, chip formation, tool wear and the cutting forces and experimental optimizations are very expensive. On this account, broaches are mostly designed fail-safe, even if the design is not optimal according to the thermal mechanical tool load, machine tool and workpiece requirements. The goal of this project is the development of a multiscale model to simulate the broaching process. The approach is supposed to show and calculate relevant interactions between process, tool and machine tool. Therefore, the broach and the process can be designed efficiently in terms of tool load, productivity and manufacturing costs. The model consists of several submodels to discretize the broaching process in different spatial and temporal scales. This makes it possible to combine the precision of a mesoscale chip formation model with a macroscopic process and machine model.