Shot peening for fatigue life improvement of aerospace strutures

喷丸强化是一种广泛用于提高航空航天工业金属部件疲劳寿命的冷加工工艺。这个过程是通过用高速弹丸轰击金属部件的表面来完成的，这些弹丸在表面附近引起塑性变形层。这种塑性变形导致喷丸表面中的残余压缩应力场，这降低了在循环载荷条件下过早失效的可能性，因此提高了喷丸部件的疲劳寿命。 该合作项目的主要目标是与工业合作伙伴合作开发表征喷丸过程的新方法。该计划的一部分是致力于建立分析和数值模型的喷丸过程的预测。实验活动的计划，以量化的喷丸参数的喷丸结果的效果，以及验证开发的模型。该计划的另一部分是评估喷丸组件的疲劳寿命改善。在循环加载过程中，在喷丸组件的裂纹萌生和扩展将实验观察和微观结构尺度的数值模拟。

Shot peening is a cold working process widely used to improve the fatigue life of metal components in the aerospace industry. This process is accomplished by bombarding the surface of a metallic component with shots at a high velocity that induce a plastic deformation layer near the surface. This plastic deformation leads to a residual compressive stress field in the peened surface that reduces the likelihood of premature failure under cyclic loading conditions and therefore improves the fatigue life of the peened component. The principle objective of this collaborative project is to develop in collaboration with the industrial partners novel methodologies for characterizing the shot peening process. One part of the program is devoted to establish analytical and numerical models for the prediction of the shot peening process. Experimental campaigns are planned in order to qualify the effect of the shot peening parameters on the peening results as well as to validate the developed models. The other part of the program is to assess the fatigue life improvement on the peened components. The crack initiation and propagation during cyclic loading in the peened component will be experimentally observed and numerically simulated in the microstructural scale.