Analysis of Mixed‐Mode Fracture Characteristics of Cracked Concrete Based on the Extended Maximum Tangential Strain Criterion

ABSTRACT In this study, two sets of Brazilian discs with a center crack (BDCC) concrete specimens were prepared. The mixed‐mode fracture characteristics were investigated under pure Mode I, mixed‐Mode I/II, and pure Mode II loading using the extended maximum tangential strain (EMTSN) criterion and digital image correlation (DIC) technique. Results based on the EMTSN criterion showed that the ‐stress in the crack‐tip damage zones was negative. This negative ‐stress decreased the crack initiation angle and increased the fracture resistance. From Mode I to Mode II, the fracture resistance increased with critical distance, whereas the crack initiation angle gradually decreased. The DIC results showed that the strain concentration first appeared in the crack‐tip region and then propagated toward the loading end, forming a typical wing‐shaped crack propagation path.