Hybrid flat-clinching of renewable raw materials

该项目的目的是实验和数值研究由于塑性变形而连接的金属和可再生原材料的平夹紧。为了首次进行硬木与金属连接的数值研究，有必要对现有的软木材料模型进行改进。通过对金属与硬木平扣连接过程的数值模拟，对金属与硬木平扣连接机理有了更深入的了解，从而为金属与硬木平扣连接过程的可重复性提供了指导。在实验结果的基础上实现有限元模型的标定。此外，平夹紧纤维板（MDF）的数值模拟是该项目的另一个重要方面。纤维板的各向同性结构可与纤维增强塑料相媲美。因此，将检查现有的纤维增强塑料材料模型对纤维板建模的适用性。通过拉伸和压缩试验，实现基体材料（粘结助剂为MDF）和增强材料（木纤维为MDF）性能的适配。为了在SPP中做出进一步的实质性贡献，将测试使用无单元伽辽金方法（EFGM）作为平夹紧有限元模拟的替代方法。由于不必要的重新啮合，EFGM特别有利于具有高塑性应变的工艺，如平夹紧。从而减少了计算时间，提高了仿真精度。由于缺乏用EFGM模拟平夹紧的技术，对常规夹紧的研究将在项目内实现。由此产生的知识增长将总结在指南中，该指南将向spp1640成员开放。此外，这些知识将用于项目内的平夹紧模拟。

The aim of the project is the experimental and numerical investigation of flat-clinching of metal and renewable raw materials due to joining by plastic deformation. For the numerical investigations of joining hardwood and metal for the first time, it is necessary to improve an existing material model for softwood. Based on the numerical process simulation for joining metal and hardwood with flat-clinching an increased knowledge of the joining mechanisms is striven, which should finally lead to guidelines for a reproducible joining process. The calibration of the FEM models will be realized on the basis of the experimental results. Furthermore, the numerical modeling of flat-clinching fiberboard (MDF) is another essential aspect of the project. The isotropic structure of fiberboard is comparable with fiber-reinforced plastics. Due to that, the applicability of existing material models for fiber-reinforced plastics for modeling fiberboard will be checked. The adaptation of the properties of the matrix material (adhesion promoter for MDF) and the reinforcements (wood fiber for MDF) will be realized by tensile and compression tests.In order to make a further substantial contribution within the SPP, the use of the Element-Free Galerkin method (EFGM) will be tested as an alternative for the FE simulation of flat-clinching. The EFGM is especially beneficial for processes with high plastic strains like flat-clinching, due to the unnecessary remeshing. This leads to a reduction of computation time and an improvement the of the simulation accuracy. Due to the missing know-how for the simulation of flat-clinching with EFGM investigations for the conventional clinching will be realized within the project. The resulting increase in knowledge will be summarized in guidelines, which will be open to the members of the SPP 1640. Furthermore, the knowledge will be used for the simulation of flat-clinching within the project.