Within the bogie, the ENR centre pivot (part 1953-3350) is a welded S355 steel assembly that transmits traction, braking and lateral forces between the vehicle body and the bogie frame through preloaded laminated rubber springs and welded damper mounts.
It is a compact, thick-plate structure carrying combined loading defined by EN 12663-1:2010 and EN 13749:2011, and its welds have to be evaluated for infinite fatigue life against DVS 1612:2014 and classified into performance classes per EN 15085-3:2007.
Ganz Motor completed the centre pivot design and needed a defensible analytical package before delivery to their end customer — an analytical package that would satisfy the certification reader and give their welding engineers a class-by-class specification to work from. They engaged eCon to verify the weld strength against DVS 1612:2014 and to produce the weld performance classification per EN 15085-3:2007.
Ganz holds the design authority and the manufacturing floor for the centre pivot. The fatigue-evaluation chain sitting between them is a specialist workflow that has always been bought in. The internal engineering capacity for stress analysis amounts to a part-time engineer — sufficient to run a mechanical calculation, but not to take those results through the weld-fatigue evaluation and standard-compliant classification chain.
For a stocky centre pivot built from very thick plates the through-thickness stress component cannot be neglected, and the standard shell workflow was considered too coarse for the analytical defensibility this programme required. eCon organised the verification chain around that constraint.
Each weld was evaluated at its foot, with the stress state resolved into its σ (normal), τ_∥ (parallel shear) and τ_⊥ (perpendicular shear) components and sampled at five integration points through the plate thickness. The three components were then combined into a DVS 1612 utilisation per weld, per load case, under symmetric alternating loading (R = −1) and the DVS 1612:2014 allowable stresses for S355. The twelve welds in the assembly spanned fatigue classes B, C−, E1−, E4, E6+, F1 and F2 — from V-shaped butt welds (V10, ½ V, ½ V20) to fillet welds (a4, a8).
Twelve welds across four load cases, three stress components each at five through-thickness points, made a manual DVS 1612 evaluation impractical. eCon implemented the calculation as a Python module that ingests the stress-component output from the ANSYS structural analysis, computes the utilisation, and renders each weld as a numbered, colour-coded segment on the geometry. The chain reruns on design variants without rework.
Four load cases were evaluated — three single-force cases (longitudinal Fx, lateral Fy, damper Fcs) each combined with the rubber-spring preload Fxr, and a fourth combined case. The utilisation, together with the safety category assigned by function, then fed the EN 15085-3:2007 performance class assignment. Because eCon works with welding specialist engineers in parallel with the design side and shares the vocabulary of both, the classification was delivered in a form the shop floor could act on directly — a specification of geometry, welding sequence and inspection class per weld.
The result is a verification chain in which every weld-fatigue decision is traceable either to a DVS 1612:2014 allowable stress or to an eCon-developed evaluation step, and in which the output is directly usable both by the certification reader and by the welding engineers on the shop floor.
Load case 4 governed at S = 2.365 on the ½ V butt welds at the side plate to web connection.
The output split cleanly across two audiences: a DVS 1612:2014 compliance report for the certification reader, and a per-weld EN 15085-3:2007 performance class specification for Ganz's welding engineers to build and inspect against.
The centre pivot passed DVS 1612 as designed. eCon built the through-thickness weld evaluation and automated the chain in Python. They worked directly with our welding engineers, who understood immediately what needed to happen on the shop floor.
— Firstname Lastname, Ganz Motor Kft.
Drop your project specs below. We'll analyze your requirements and get in touch within 2 business days to discuss the technical approach.
