“…In some studies, the viscoelastic behavior is neglected and thus the numerical implementation into commercial software applied to a finite element analysis, such as ABA-QUS, is relatively easy; however, this might be unsuitable for cases discussing long-term durability [13,20,21,22,23,24,25,26]. Many studies have employed non-linear viscoelastic-viscoplastic constitutive equations to express the time-dependent stress-strain relationships of matrix resins [27,28,29,30,31,32,33,34,35,36]. For example, there have been studies on applying damage as a factor in a non-linear viscoelastic-viscoplastic constitutive equation [37,38,39,40,41].…”