基于子模型法的带有表面裂纹钢丝应力强度因子研究

钢丝裂纹应力强度因子是进行钢丝疲劳断裂寿命评估、疲劳裂纹扩展分析和钢丝断裂强度评估等工作的重要参数。本文首先介绍了裂纹扩展分析软件FRANC3D,然后基于子模型法模拟研究了拉伸荷载作用下带有表面裂纹钢丝的应力强度因子,裂纹种类包括直线形裂纹和半圆形裂纹,最后拟合得到拉伸荷载作用下带表面裂纹钢丝的应力强度因子形状修正系数表达式,分析了利用该公式进行承载力评估时产生误差的原因。研究结果表明,利用子模型模拟分析拉伸荷载作用下带有表面裂纹的钢丝应力强度因子时计算精度高,计算速度快,对计算机硬件要求低;利用该方法得到的钢丝裂纹应力强度因子,在进行索承式桥梁吊索安全性能评估时,评估结果更精确。

Crack stress intensity factor of wire with surface crack based on sub-model method

The crack stress intensity factor is an important parameter for wire fatigue fracture assessment, wire fatigue crack growth analysis and wire fracture strength assessment. In this paper, the crack extension analysis software FRANC3D was introduced firstly, then the stress intensity factor of wire with surface crack was studied under tensile loads based on sub-model simulation method, and the types of cracks include semicircular semicircular crack and linear crack, and the shape correction coefficient expression of stress intensity factor was fitted under tensile loads. The causes of errors by using this formula when evaluating strength were analyzed. The results show that the precision of calculating stress intensity factor is higher compared with the existing research results, and the method had higher calculation speed, and the demand for computer hardware is low, and when the safety performance of cables for cable-supported bridge is evaluated using the stress intensity factor obtained by this method, the result is more accurate.