Effects of a circular hole on the propagation behavior of double running cracks under impact loading

Abstract

In order to study effects of a circular hole on the propagation behavior of double running cracks under impact loading, the three-point-bending impact experiments of polymethyl methacrylate (PMMA) specimens with a circular hole were carried out by using the optical caustics method, and the numerical simulation was carried out by using the extended finite element method (XFEM) in ABAQUS software. The results show that under the influence of the stress field around the circular hole, the propagation trajectory of double running cracks can be divided into three stages: "exclusion" stage; first "attraction" and then "exclusion" stage; neither "attraction" nor "exclusion" stage. The circular hole defect affects the propagation velocity of double running cracks and the dynamic stress intensity factors $K_{\mathrm{I}}^d$ at the crack tip. The maximum principal stress between the running cracks and the circular hole decreases with crack spacing a. When the double running cracks’ tips are on both sides of the circular hole, the maximum principal stress between the running cracks and the circular hole reaches the minimum.

Keywords:

• Circular hole
• double running cracks
• caustics
• crack propagation
• XFEM

Disclosure statement

None.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant numbers 51974318, 52174094].