面向航空发动机减重的铝合金管强化机理研究

为助推新一代大型航空发动机推重比的有效提升,开展面向航空发动机减重需求的高强度铝合金管件自增强机理研究。采用有效强化的高强度铝合金管件大规模替换航空发动机低温段不锈钢高压管件,是实现航空发动机减重的可行方法。通过研究高强度铝合金管件自增强工艺的强化机理,建立基于三剪统一强度准则,同时考虑包辛格效应、应变时效以及应变硬化的高压自增强工艺参数数学模型,并结合双线性随动强化模型,分析管路构件在强化过程中的弹塑性行为与残余应力分布演化规律,研究确定强化工艺参数。基于ANSYS,在额定工况下对强化后的铝合金管件和不锈钢管件的疲劳强度进行仿真分析,最后采用脉冲疲劳试验进行验证,证明自增强铝合金管件替换现役不锈钢管件具有较好的可行性。

Research on Strengthening Mechanism of Aluminum Alloy Pipe for Aero-Engine Weight-Reduction

In order to promote the effective improvement of thrust-to-weight ratio of new generation of large aeroengines,the research on autofrettage mechanism of high-strength aluminum alloy pipe fittings for aero-engine weightreduction requirements was carried out.It is a feasible way to reduce the weight of aero-engines that using effectively strengthened high-strength aluminum alloy pipe fittings to replace stainless steel high-pressure pipe fittings in the low temperature section of aero-engine on a large scale.To obtain the mathematical model of the high-pressure autofrettage process of aviation pipeline,the strengthening mechanism of high-pressure pipeline autofrettage process was researched and Bauschinger effect,strain aging and strain hardening based on the triple shear unified failure criterion were considered.The bilinear kinematic hardening model was used to analyze the elasto-plastic behavior of the pipeline during the hardening process and the evolution of the residual stress distribution.Based on ANSYS,the fatigue strength of reinforced aluminum alloy pipe and stainless steel fittings were simulated and analyzed under rated conditions.Finally,pulse fatigue experiments were done to verify that it is feasible to replace existing stainless steel fittings with strengthened aluminum alloy pipe fittings.