To construct a static finite element analysis model of a self-expanding braided colorectal stent, we investigated the effects of contact conditions, convergence criteria, and time step size on the analysis results. A compression–expansion simulation of the colorectal stent was performed to compare the influence of the BIAS value, which defines the contact detection distance, on the penetration of wire elements, as well as the effects of convergence criteria and time step size on expansion force. Setting the BIAS to 0.95 effectively suppressed penetration between wire elements. Adjusting the convergence criteria did not reduce the variability of the expansion force. In contrast, modifying the time step size reduced the variability of expansion force up to a stent diameter of 12 mm; however, for diameters below 8 mm, the variability could not be suppressed.
Koyama et al. (Wed,) studied this question.