用切口尖端应力方法分析V形切口的应力强度因子

ANALYSES OF STRESS INTENSITY FACTORS OF V-NOTCHES BY A NOTCH-TIP STRESS METHOD

为了基于传统有限元法分析圆轴中的V形切口尖端的奇异性应力场的高精度数值解,建立一种切口尖端应力方法,用于计算V形切口的应力强度因子。该方法不需要在V形切口尖端采用反映应力奇异性的奇异单元。求解时,首先给定参考问题的广义应力强度因子,然后利用待求问题的应力值与参考问题的应力值之间的比值来求解待求问题的广义应力强度因子。算例采用切口尖端应力方法分析圆轴中的V形切口问题。计算结果表明,该方法计算精度较高,能方便地用于求解相关的工程问题。

In order to analyze numerical solutions of singular stress fields in tip of a V-notched round bar exactly based on the conventional finite element technique,a finite element method（FEM） called as the notch-tip stress method（NTSM） was developed to solve generalized stress intensity factors（GSIFs） of V-notches.The method don＇t need special elements accounting for the analytical form of a singularity.The stress values at the notch tip calculated by FEM were used and the stress intensity factors of sharp angular corners were evaluated from the ratio of stress values between a given problem and a reference one.As application,the NTSM was used to solve GSIFs of V-notches in round bars.All numerical examples prove that the present method is effective to deal with sharp angular notch problems.