某型飞机翼身连接接头可靠性分析  

RELIABILITY ANALYSIS FOR THE WING-FUSELAGE JOINT OF AN AIRCRAFT

作　　者：王燕萍[1] 吕震宙[1] 杨子政[1] 

机构地区：[1]西北工业大学航空学院,西安710072

出　　处：《机械强度》2005年第6期762-765,共4页Journal of Mechanical Strength

基　　金：航空基金(00B53010);航天基金(N3CH0502;N5CH0001);陕西省自然基金(N3CS0501)联合资助项目

摘　　要：首先将标准有限元程序与改进的均值法相结合,对某型飞机翼身连接接头处的刚度可靠性进行分析,结果表明在所给载荷和允许应变的情况下,该接头结构在外载变异系数为0.15,弹性模量和剪切模量的变异系数分别为0.05时仍具有较高的可靠度。然后又将标准有限元分析程序与响应面法结合,在假设接头的响应极限状态方程为一不包括交叉项的二次多项式的基础上,利用有限元分析确定响应极限状态方程,通过迭代运算,保证响应极限状态方程在最有可能失效点处与接头结构真实的隐式极限状态方程有很好的近似程度。两种方法的计算结果具有较好的一致性。最后基于弹塑性应变分析,给出大过载情况下低周疲劳寿命可靠性分析结果,得到在给定寿命要求下结构可靠度随疲劳寿命变异系数变化的曲线,并给出在要求可靠度情况下安全寿命随疲劳寿命变异系数的变化曲线,为该型飞机的设计定型提供依据。For implicit limit state equation, the standard finite element code is combined with advanced-mean-value-first-order （AMVFO） method, to analyze the stiffness reliability for the wing-fuselage joint of an aircraft. Under the required performance, the results indicate that the joint structure applied by the given load has a higher reliability when coefficient of variation in the applied load is 0.15 and those in elastic modulus and shear modulus are 0.05 respectively. Then the standard finite element code is combined with the iterative response surface method （RSM） to analyze stiffness reliability. The response limit state equation is assumed as a quadratic polynomial with no cross terms. The finite element software is employed to obtain the response limit state equation. By iterative calculation, the response limit state equation is gradually convergent to the actual implicit limit state equation of the joint structure at the most probable failure point. The calculation results of the RSM and the AMVFO are in good agreement. Finally based on elasticity-plasticity strain analysis, the reliability analysis for low cycle fatigue life is discussed. The fatigue reliability is obtained at the given life requirement. And the safety life is obtained at the given reliability requirement.

关 键 词：可靠度 一次二阶矩法 响应面法 改进的均值法 

分 类 号：V215.7[航空宇航科学与技术—航空宇航推进理论与工程] TB114.3[理学—概率论与数理统计]