Investigation of a metamodel-based methodology to optimise the component properties of discontinuous long fibre reinforced plastics by systematic design of manufacturing processes

非连续长纤维增强塑料（DLP）目前代表纤维复合材料领域中最重要的材料类别之一。对于这些材料的加工，一次成形工艺通常用于生产近净形部件。在处理期间，发生DLP的流动。这会影响纤维的取向，从而决定零件的机械性能。由特定工艺配置产生的机械性能可以通过模拟来预测。然而，由于这些都是计算昂贵和耗时，不是所有可能的配置可以模拟，这限制了达到所需的机械性能profile.该项目的目的是一种方法，用于优化DLP加工过程中使用的热固性和热塑性DLP的压缩成型的初始占用状态的例子.由于这一过程的高度复杂性和长链的行动，元建模方法的成形影响的最终零件的属性进行了追求。通过元建模，可以复制通过绘制复杂模型或上下文的样本确定的关系。为了根据项目中使用的优化目标（扭转和三点弯曲下的零件变形最小化）优化工艺，借助遗传算法对元模型进行迭代评估，并通过额外的工艺配置和变形进行扩展。的收敛行为的优化方法进行了调查，其依赖程度的元模型抽象，部分几何形状，负载情况和温度引起的材料effects.The建模，因此进行了两个不同的抽象层次。在第一个抽象层次上，输入参数和所得到的组件偏转之间的直接关系进行建模。这种方法也称为“黑盒”，它忽略了加工过程中DLP的行为以及流动和机械部件特性之间的复杂关系。在第二个抽象级别上，两个元模型是耦合的。首先，创建了DLP在该过程中的不连续流动的元模型，从而创建了材料行为本身的元模型。其次，黑盒方法用于对所产生的组件行为进行建模。因此，一个孤立的近过程元建模的影响分析是可能的。元模型的验证将通过交叉验证来执行。此外，还将对优化方法的可推广性进行评价。

Discontinuous long fibre reinforced plastics (DLP) currently represent one of the most important material classes in the field of fibre composites. For the processing of these materials, primary forming processes are generally used to produce near-net-shape components. During processing, flowing of the DLP occurs. This influences the fibre orientations, determining the mechanical properties of the part. The mechanical properties resulting from a specific process configuration can be predicted by simulation. However, since these are computationally expensive and time-consuming, not all possible configurations can be simulated, which limits reaching a desired mechanical property profile.The aim of the project is a methodology for the optimisation of DLP processing processes using the example of the initial occupancy state in the compression moulding of thermoset and thermoplastic DLP. Due to the high complexity of this process and the long chains of action, the metamodeling approach of the shaping influences on the final part properties is pursued. By metamodeling, relationships can be replicated that were determined by drawing samples of a complex model or context. In order to optimise the process with regard to the optimisation goals used in the project (minimisation of part deformation under torsion and three-point bending), the metamodels are evaluated iteratively with the aid of a genetic algorithm and extended by additional process configurations and resulting deformations. The convergence behaviour of the optimisation approach is investigated with respect to its dependence on the degree of metamodel abstraction, part geometry, load case and temperature induced material effects.The modelling is therefore carried out on two different abstraction levels. On the first abstraction level, the direct relationship between input parameters and the resulting component deflection is modelled. This approach, also called "black box", neglects the behaviour of the DLP during processing as well as the complex relationships between flow and mechanical component properties. On the second abstraction level, two metamodels are coupled. Firstly, a metamodel of the discontinuous flow of the DLP during the process and thus of the material behaviour itself is created. Secondly, a black box approach used for modelling of the resulting component behaviour. Therefore, an isolated analysis of the influence of near-process metamodeling is possible. Validation of the metamodels will be performed by cross-validation. Additionally, an evaluation of the generalizability of the optimisation approach will be carried out.