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，因为它是飞机上机械要求最多的部件，具有非常严格的几何公差。世界领先的着陆系统公司Safran Landing Systems希望提高生产率，以增强竞争力。制造高强度钢制起落架的过程包括许多加工步骤，以使产品达到所需的几何形状，并进行热处理以获得所需的机械性能。然而，热处理过程伴随着几何形状的变化，导致可能的零件不合格，从而导致昂贵的让步过程，有时以零件拒收结束。为了避免这种情况，需要一个预测性模型来量化这种变化。通过试错来改进是非常昂贵的，也是不可行的。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域的相互作用，如热、冶金和机械域，使得问题非常复杂。由于物理模型的过度简化，现有的仿真模型无法提供所需的精度。因此，该项目将致力于加深对热处理过程中涉及的热-金属-机械相互作用的了解，以最终拥有更强大的预测模型。

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.