基于有限元的方向舵分配机构延寿技术研究

Research on Life Extension Technology of Rudder Distribution Mechanism Based on Finite Element Method

某型方向舵分配机构延寿研究是飞机延寿研究的重要组成部分,方向舵分配机构延寿研究过程重点对壳体进行疲劳寿命估算;针对目前常用延寿方法的不足,提出了一种延寿综合决策方法,在分析产品延寿可行性、确定延寿目标和壳体为薄弱环节后,应用有限元分析及细节疲劳额定值(DFR)对壳体开展疲劳寿命估算;首先,通过有限元仿真,分析到寿方向舵分配机构壳体在额定工况下各主要功能管道的最大应力值,确定壳体是否满足静强度设计要求;其次,应用细节疲劳额定值(DFR)方法,对壳体疲劳寿命进行37.5万次(延寿目标值对应耐久试验循环次数)耐久试验循环校核;最后对壳体开展实验验证;实验结果表明,壳体未出现裂纹和其它机械损伤等现象,满足飞机的延寿使用需求,与仿真计算结果一致,验证了采用的延寿综合决策方法的正确性。

Research on the life extension of the rudder distribution mechanism is an important part of airplane life extension research,the research focus of the rudder distributing mechanism is to conduct the fatigue life tests on the shell of airplane.In view of the shortcomings of the common life extension methods,a comprehensive life extension decision-making method is proposed in this paper.After analyzing the feasibility of product life extension,determining the life extension target and shell as a weak link,the finite element analysis and detail fatigue rating(DFR)are used to estimate the fatigue life of the shell.Firstly,through the finite element simulation,the life rudder distribution mechanism shell is analyzed to find out the maximum stress value of various pipelines in the work condition,which determines whether the shell meets the requirements for the static stress;Secondly,the method of DFR is used to check the Fatigue Life of the shell by 375000 times(circulation number of times between life extension and endurance test)in the endurance tests.Finally,the experimental verification on the shell is conducted.The experiment results show that there are no cracks or other mechanical damage in the shell,which meets the requirements of the airplane life extension and is in accordance with the simulation results.it is verified that the proposed life comprehensive decision-making method is correct.