PSI - Issue 77

Christian J. Silva et al. / Procedia Structural Integrity 77 (2026) 631–638 Silva et al./ Structural Integrity Procedia 00 (2026) 000–000

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1. Introduction Crashworthiness refers to the ability of a structure to withstand and manage impact energy while preserving the integrity of critical areas and minimising injury risks to occupants (Lopes et al., 2023). Originally developed in the automotive and aerospace fields, the concept has gained particular importance in the railway sector, where collisions can involve large masses, high energies, and significant consequences for passenger safety (Gao and Wang, 2019). For railway vehicles, crashworthiness is not only a measure of structural resilience but also a regulatory requirement, as European standards such as EN 15227 define performance criteria and test scenarios that must be satisfied for certification. Within this context, the present study investigates the crashworthiness behaviour of a railway coach subjected to a head-on collision, using finite element simulations to assess compliance with key regulatory indicators and to identify structural weaknesses that may compromise safety. Several authors have applied numerical crashworthiness analyses to passenger rail vehicles, seeking to improve energy absorption and structural performance through design modifications. For example, Molatefi et al. (2016) analysed a passenger rail coach under frontal impact, proposing reinforcement strategies to enhance energy absorption in the buffer and side structures. Zhu et al. (2020) developed finite element models of metro vehicle bodies made from different materials, comparing energy absorption, deformation, and collision force transfer path under rigid-wall impact simulations. Xie et al (2019) simulated a subway train collision in the context of EN 15227 and evaluated contributions of anti-climbing devices, couplers, and draft gears to energy absorption, as well as survival space and train acceleration. Building on these contributions, the present study addresses the crashworthiness of a passenger railway coach, comparing baseline and modified structures in terms of failure behaviour and certification-oriented criteria, which remains less explored in the literature. 1.1. European Regulation EN 15227 In Europe, the principal regulatory framework for crashworthiness is provided by EN 15227, which establishes mandatory design scenarios and performance requirements for railway vehicles. These requirements include maintaining sufficient survival space, preventing vehicle override and derailment, and limiting deceleration levels transmitted to passengers (CEN, 2020). As for the scope of the present work, only the following criteria will be taken into account for assessing the vehicle structures: Survival space preservation : Criteria #2: At the vehicle ends, survival space can be reduced up to 100 mm in the last 5 m. • Limitation of deceleration levels: For each vehicle being assessed, the maximum value of the mean deceleration calculated using moving averages over any time interval of duration 30 ms shall not exceed 10 g. 2. Methodology 2.1. Finite Element Model Development A Finite Element Model of the intermediate coach of a passenger train was developed using the HyperMesh software. Figure 1 depicts the baseline vehicle structure under study. The components of the structure were modelled using approximately 16 million reduced integration elements, which include the non-structural masses distributed to simulate the weight of the equipment and passengers, and spring elements used to simulate spot and seam welds between components. Table 1 provides a summary of the number and types of elements employed, and Table 2 contains the design masses considered according to regulation EN 15663 (CEN, 2018). •