基于静强和寿命可靠性的双辐板涡轮盘/榫结构优化设计方法

Optimization design method for twin-web turbine disk/tenon structure based on static strength and life reliability

为保证双辐板涡轮盘/榫结构疲劳寿命及可靠性,提出基于静强和寿命可靠性的涡轮盘/榫结构优化设计方法.采用盘身轴对称模型和涡轮盘/榫三维模型交替优化策略,进行轮盘静强结构优化.结合材料应力-寿命数据,对满足静强准则的涡轮盘/榫结构进行考虑尺寸效应的寿命可靠性分析,并建立各危险区域给定可靠度的峰值应力-寿命曲线.基于涡轮盘/榫静强优化设计平台,利用给定可靠度的应力-寿命曲线数据修改结构优化单点应力标准.在保证不出现轮盘破裂的前提下,将轮盘寿命可靠性优化的复杂过程简化为基于应力标准的寻优过程.典型例优化结果表明:静强优化后涡轮盘/榫的寿命不能满足设计要求;经寿命可靠性优化后,轮盘疲劳寿命较优化前增加了47.28%,满足寿命可靠性设计要求;且在轮盘静强优化质量减轻16.66%的基础上,再减轻3.43%;该方法在保证优化精度的条件下,可大幅提高优化效率,且易于工程设计中应用.

In order to guarantee the fatigue life reliability of twin-web turbine disk/tenon,a method of optimization design based on static strength and life reliability was put forward.With introduction of the optimization strategy of the disk＇s axisymmetric model and the turbine disk/tenon three-dimensional model in turn,the static strength optimization was in progress.According to the material stress-life data,the life reliability of turbine disk/tenon structure already meeting the static strength criteria was analyzed in consideration of the size effect.Stress-life curves of different zones for a given reliability were established.The point stress criterion of the static strength optimization was modified according to the stresslife curves.On the premise that the disk wasn＆#39;t broken,the complex optimization process based on life reliability was simplified based on stress standard.A typical example showed that the static strength optimization result could not meet the design requirements of life reliability.Through the life reliability optimization design,the structural life was prolonged by 47.28% and met the design requirement of reliability life.And on the basis of the turbine disk/tenon mass reduction by 16.66% during the static strength optimization,the total mass reduced 3.43 % in life reliability optimization again.Under the conditions of ensuring the accuracy of the optimization.The method can significantly improve the optimization efficiency,enabling convenient engineering applications