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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Fig. 1. Intermediate coach Finite Element Model developed

Table 1. Mesh properties of the Finite Element Model

Element type

Number of elements

1D: Beam, Rigid and Spring elements 245,175 2D: Shell elements 16,086,682 3D: Solid elements 122,112

Table 2. Non-structural masses considered

Seatings and 50 % of seated passengers

5.2 ton 1.55 ton

Staff and design consumables

Bathrooms 1.6 ton Auxiliary converter and battery coffrets 2.15 ton Wastewater tank 0.75 ton Windows 0.56 ton Lateral and gangway doors 0.30 ton Air conditioning 0.95 ton Interior fittings 2 ton

In terms of material modelling, the steel alloys that compose the vehicle structure were modelled using the Johnson Cook formulation (Murugesan and Jung, 2019) to characterise isotropic elasto-plastic materials following Equation 1, where: • - Flow stress (Elastic + Plastic components); • - Plastic strain (True strain); • - Yield stress; • - Strain rate coefficient; • - Strain rate; • 0̇ - Reference strain rate; • - Temperature exponent; • - Melting temperature in Kelvin degrees. The mechanical properties used for this constitutive law are presented in Table 3 and were derived from stress strain curves obtained by tensile testing. Strain rate and temperature effects were not considered due to a lack of available data at this stage of the project. = � + �� 1+ ln ̇ 0̇ � (1 − ∗ ) (1) Table 3. Mechanical properties of the used steel alloys • - Hardening modulus; • - Hardening exponent;

ρ , [tonne mm 3 ⁄ ] E, [MPa]

1.0570 S355J2G3 7.9×10 −9 7.9×10 −9 7.9×10 −9 200000 200000 C1000 C850 207000

Density

Young’s Modulus