Development of a comprehensive process model for accurate prediction of quench induced distortion in a large size aircraft landing gear

起落架的制造需要特别注意，因为它是飞机上最机械的部件，具有非常严格的几何公差。SAFRAN着陆系统公司是着陆系统领域的全球领导者，该公司希望提高其生产效率，以提高竞争力。制造由高强度钢制成的起落架的过程包括许多加工步骤，以使产品具有所需的几何形状和热处理以达到所需的机械性能。然而，热处理过程伴随着几何形状的变化，可能导致零件不符合要求，从而导致昂贵的让步过程，有时以零件报废告终。为了避免这种情况，需要一个预测模型来量化这种变化。通过试错来改进是非常昂贵且不可行的。使用数值模拟是一个有趣的选择；然而，热处理过程涉及不同物理领域如热、冶金和力学领域的相互作用，使问题非常复杂。由于物理模型过于简化，现有的仿真模型无法提供所需的精度。因此，该项目旨在加深对热处理过程中涉及的热-金属-机械相互作用的了解，最终建立更强大的预测模型。

The manufacture of a landing gear requires special attention because it is the most mechanically solicited component of an aircraft with very tight geometric tolerances. SAFRAN Landing Systems, a world leader in landing systems, wants to increase its productivity in order to be more competitive. The process of manufacturing a landing gear made of high strength steel includes many machining steps to give the produce the desired geometry and a heat treatment to attain the required mechanical properties. However, the heat treatment process is accompanied by a change in geometry leading to possible part non-conformance thus resulting in an expensive concessions process sometimes ending with part rejection. To avoid this, a predictive model is needed to quantify this change. Improvement by trial and error is very expensive and non-viable. The use of numerical simulation is an interesting choice; however, the heat treatment process involves interactions of different physical domains such as the thermal, metallurgical and mechanical domains, making the problem very complex. Existing simulation models are unable to provide the required accuracy due to over-simplification of the physical models. As a result, the project will aim to deepen knowledge about the thermo-metallo-mechanical interactions involved in the heat treatment process to eventually have a more robust predictive model.