The thesis introduces the work of calculating local stress and local strain by application of Levenberg-Marquardt' s iteration method. As an usual mathematical method to solve super equation, Levenberg-Marquardt' s iteration method has some disadvantages such as complicated program, low computing efficiency. Therefore, the paper aims to find out a comparatively simple, high efficient and high precision computing method. Through comparing and analyzing the efficiency and precision of dichotomy and Levenberg-Marquardt' s iteration method by which solving strain life equation and local strain range, the thesis proves that the application of dichotomy is simple and applicable for the engineering. At last, through combination with the case of plane' s drilled component, applying local stress strain method to calculate the parts' predictive life and comparing that result with the experimental life value, the paper concludes that strain life equation which concerns mean stress correction more fit for engineering requests.%介绍了应用Levenberg-Marquardt迭代法计算局部应力和局部应变的工作.Levenberg-Marquardt迭代法是求解超越方程的一种常用数学方法,但是缺点是程序比较复杂,计算效率较低,因此本文目的是找到一种程序实现简单、计算效率高、计算精度满足要求的计算方法,选择了二分法,并且对比分析了二分法和Levenberg-Marquardt迭代法求解局部应变与应变寿命方程的效率和精度,从而得出应用二分法来进行求解是简单并且可以被工程应用的:最后结合某飞机结构一种带孔部件的实例,应用局部应力应变法给出了该部位的寿命预测值,通过和试验寿命值的对比,得出了考虑平均应力修正的应变寿命方程才更符合工程要求.
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