To investigate the effect of mechanical properties and non-adhesion region boundaries in coke on behavior of coke, fracture analyses using RBSM (Rigid Bodies-Spring Model) were carried out for coke. First, the fracture analyses with RBSM assuming 4-point bending tests were carried out for two cases by applying the approximate equations of the shear strength. The approximate equation of the shear strength derived from internal friction angle and the one for brittle materials like glasses and rocks were applied to analytical objects. When the approximate equation of the shear strength for brittle materials like glasses and rocks was applied, analytical results reproduce the fracture behavior better than the other one. It is known that non-adhesion region boundaries in coke influences coke strength, so the fracture analyses with RBSM assuming 4-point bending tests were also carried out to investigate the effect of non-adhesion region boundaries in coke. Analytical results showed that the fracture started at non-adhesion region boundaries when non-adhesion region boundaries were located under region of high stress. It was also indicated that fracture loads varied due to the difference in fracture strength at non-adhesion region boundaries even if non-adhesion region boundaries existed at the same point. As a result, it is supposed that non-adhesion region boundaries in coke influence crack propagation and fracture load and are the important intensity factor.
