ABSTRACT
The wire crack stress strength factor is an important parameter for the fatigue fracture life evaluation, fatigue crack growth analysis and wire fracture strength evaluation of steel wire. In this paper, the crack propagation analysis software FRANC3D is introduced first, and then the stress intensity factor of steel wire with surface double cracks under different tensile loads is simulated based on the submodel method. The research subjects of double cracks are parallel double cracks and collinear double cracks. Taking the stress intensity factor of a surface single crack as the control parameter, the influence of the size, position and tensile load of the auxiliary cracks on the interaction between cracks is discussed when the size of the main crack is constant. The results show that when the depth of the main and auxiliary cracks of the parallel double cracks is equal and the distance between the parallel double cracks is closer, the interaction between the main and auxiliary cracks is only shielding. With the increase of the depth ratio or parallel spacing of the main and auxiliary cracks, the shielding effect between the parallel double cracks will gradually weaken; When the main and auxiliary crack depths of collinear double cracks are equal and the angle between collinear double cracks is smaller, the interaction between main and auxiliary double cracks is only manifested as enhancement, and the enhancement effect between main and auxiliary double cracks will gradually weaken with the increase of the ratio of main and auxiliary crack depth or circumferential angle. It is more effective to evaluate the fatigue life and fracture strength of double-crack steel wire by using the variation law of stress intensity factor of double-crack steel wire.
