“…Other authors have proposed co-simulation methodologies using Finite Element Method (FEM) and multibody formulations in order to study the flexibility of track structures under realistic trainset loads [31][32][33][34]. These developments open up the possibility of integrating more detailed wheel-rail contact models [35][36][37][38][39][40][41][42][43][44], to consider track irregularities [45,46] and other track singularities [10,[47][48][49][50] in the studies aiming to assess track performance and degradation evolution [51][52][53][54][55] under realistic operation conditions.…”