大尺寸盘榫结构件疲劳寿命优化设计及验证方法研究

Fatigue Life Optimization Design and Verification Method of Large-Size Disc and Tenon Structure

关键词:  大尺寸结构件  盘榫结构  B样条曲线方法  低周疲劳  模拟件设计

Key words:  Large-size structure  Disc and tenon structure  B-spline curve method  Low cycle fatigue  Simulation design

摘要:

针对航空发动机及燃气轮机设计中盘榫应力集中导致的结构件寿命瓶颈问题，导入三次B样条曲线优化理念，以较低设计参数调整维度代价获得了定性合理、可变性较大的榫槽优化结构，稳定提高了设计优化速率和泛化能力。面向大尺寸盘榫结构件，提出根据优化前后榫槽应力集中位置的应力水平和梯度设计模拟件进行验证，保证了大尺寸结构件设计方案验证的等效性和充分性。仿真结果显示，优化后的盘榫结构件最大应力降低45%，低周疲劳寿命提高约36倍；基于应力集中和梯度设计的模拟件验证结果与仿真结果一致，印证了优化收益和验证方法可靠性，对于大尺寸结构件疲劳试验设计具有普遍借鉴意义。

Abstract:

Aiming at the bottleneck problem of structure life caused by tenon stress concentration in aero-engine and gas turbine design， the concept of cubic B-spline curve optimization is introduced. A qualitatively reasonable and variable tenon optimization structure is obtained at a lower design parameter adjustment dimension cost， which steadily improves the design optimization rate and generalization ability. For the large-size disc and tenon structure， it is proposed to design the simulation according to the stress level and gradient of the stress concentration position of the tenon before and after optimization， which ensures the equivalence and adequacy of the design verification of the large-size structure. The simulation results show that the maximum stress of the optimized disc and tenon structure is reduced by 45%， and the low cycle fatigue life increases by 36 times. The verification results of the simulation parts based on stress concentration and gradient design are consistent with the simulation results， which reflects the optimization benefits and the reliability of the verification method， which can be used as a universal reference for the fatigue test design of large-size structures.