考虑热、弹、流耦合的航空发动机齿轮箱壳体拓扑优化分析

Topology Optimization Analysis of Aero-engine Gearbox Housing Considering the Coupling of Thermal Elastohydrodynamic Lubrication

为提高航空发动机齿轮箱壳体的结构性能,减小发动机恶劣工况对壳体产生的不利影响,采用基于变密度法的拓扑优化理论,以最小柔度指数和加权平均模态特征值为目标函数,考虑壳体所处环境的热、弹、流等耦合影响,以最大变形不超过0.15 mm、等效应力不大于材料屈服应力为约束条件,对航空发动机齿轮箱壳体进行了拓扑优化设计;根据拓扑优化结果,对壳体结构进行了几何重构,并对优化前、后壳体结构的强度、刚度、质量进行了对比分析。结果表明,优化后的壳体质量由5.53 kg下降到5.107 kg,减重7.64%;壳体最大变形由0.1731 mm下降到0.127 mm,变形减小26.6%;壳体最大等效应力由124 MPa下降到116.9 MPa,等效应力减小5.7%。在减小壳体质量的同时,有效地降低了壳体的最大变形和等效应力,显著提升了壳体的强度和刚度。对提高航空发动机齿轮箱传动壳体可靠性和寿命具有重大意义。

In order to improve the structural performance of the aero-engine gearbox housing and reduce the adverse effects of the engine bad working conditions on the supporting components,the topology optimization theory based on variable density method is adopted,and the minimum flexibility index and weighted average transverse eigenvalue are taken as the target number,and the coupling of thermal-elastohydrodynamic-lubrication effects of the supporting components are considered.Taking the maximum deformation less than 0.15 mm and the equivalent stress less than the material stress as the constraint conditions,the topology optimization design of the aero-engine gearbox housing is carried out.According to the topology optimization results,the geometric reconstruction of the housing structure is carried out,and the strength,stiffness and mass of the shell structure before and after optimization are compared and analyzed.The results show that,after optimization,the housing mass is reduced from 5.53 kg to 5.107 kg,the weight is reduced by 7.6%,the maximum deflection of the housing is reduced from 0.1731 mm to 0.127 mm,the deformation is reduced by 26.6%,the maximum equivalent stress of the housing is reduced from 124 MPa to 116.9 MPa,the stress is reduced by 5.7%.The maximum deformation and equivalent stress of the housing are effectively reduced,and the strength and stiffness of the housing are significantly improved.It is of great significance to improve the reliability and service life of aero-engine central transmission shell.