An Estimation of the Crack Growth Mechanism in the Coking Process: The behavior of fracture mechanics parameter

The behavior of the fracture mechanics parameter is studied by the estimated thermal stress distribution of the coke fissure in the initial stage of carbonization where the incremental theory is applied, and the CTOD (Crack Tip Opening Displacement) is evaluated as the parameter. The predicted CTOD is in good agreement with the experimental results, in which the CTOD increased with the heating rate. Furthermore, a sharp increase in CTOD is predicted near the transition point from the first maximum point of contraction coefficient of coke to the second maximum point, at which point the fissure on the coke surface would be produced. The predicted stress intensity factor derived from the thermal stress distribution near the fissure also increases with the heating rate and its behavior follows the experimental results.