Abstract
The forming mechanism of the factory-roof fracture in circumferential notched specimen is numerically investigated by using the smeared crack model based on the finite element method. In this numerical investigation we obtained the appearance of factory-roof like cracks in the specimen with the steep notch, and we numerically found out the critical condition of notch-slope for forming the factory-roof fracture patterns. Furthermore, the relationship between angle of external-torsion and numerical iteration were investigated. As a result, we obtained some characteristic tendencies for each case of the fracture shaped like an X or a factory-roof.
