Stitched catenary benchmark. PACDIN statement of methods

This paper presents the PACDIN (PAntograph-Catenary Dynamic INteraction) software participating in the latest international benchmark for stitched catenaries. Since its inception in 2014 in collaboration with Patentes Talgo, S.L.U., PACDIN has undergone a significant transformation, evolving from a validated code for simple geometries into a highly versatile and modular tool based on the Absolute Nodal Coordinate Formulation (ANCF). The current version integrates advanced modelling capabilities, such as generic track layouts, complex cantilever assemblies, mechanical tensioning systems, and non-linear pantograph models. Furthermore, the software now features a real-time solver for Hardware-in-the-Loop (HiL) testing and optimisation modules. The results obtained in this benchmark demonstrate that PACDIN's results fall consistently within the range reported by the other international participating codes. No significant discrepancies were observed in the static or dynamic analyses, confirming that PACDIN provides an accurate and reliable representation of the pantograph-catenary interaction while maintaining high computational efficiency.