PSI - Issue 28

Yifan Li et al. / Procedia Structural Integrity 28 (2020) 1140–1147 Author ame / Structural Integrity P ocedia 00 (2019) 000 – 000

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Fig. 1. The process of making circular shaped specimens.

2. The new test specimen The loading configurations and geometry of the new specimen, called Holed-Cracked Square Plate (HCSP), are shown in Fig. 2. The specimen is a square plate with edge length W and thickness B containing a central hole with diameter D and two radial cracks initiated from the circumference of the internal hole. In this paper, the distance between two crack tips is regarded as the length 2 a according to the research by Akbardoost et al. (2017). Two opposite tensile loads P are applied at the top and bottom ends of circumference of the preset hole. We can obtain different combinations of mode I and mode II fracture by changing the orientation angle β between the crack and the direction of applied load. This specimen is easy to manufacture and only needs conventional tensile testing machines with simple loading configurations. In addition, the preset hole is more favorable for introducing the crack compared with other central cracked specimens (Akbardoost et al. 2017; Hadei et al. 2017; Ayatollahi and Aliha 2009). In this paper, the specimen is only considered using for isotropic materials. A calibration is needed before using if people want to extend the use of this specimen to anisotropic materials.

Fig. 2. The test configurations (left) and geometry (right) of HCSP.