Developing and validating a crashworthy rail seat to a contracted rail standard represents a real challenge: The seat has to be designed so that it is strong enough to withstand the load of occupants under a high acceleration into the seat structure, but soft enough to not cause serious injuries to an occupant impacting the seat from a neighbouring row of seats. It usually involves a high number of time consuming and costly physical tests. Transcal Rail together with Altair ProductDesign UK applied advanced Finite Element (FE) analysis, using Radioss HyperWorks, to develop and optimise the seat design to meet structural requirements and record injuries from fully representative instrumented dummy models. The physical test set up is virtually replicated including correct dummy positioning and specifying the sled pulse curve as a prescribed motion. Crucially, it can be done prior to any materials being ordered or tools manufactured thus potentially eliminating a complete prototype testing phase altogether. The FE model can be created with various degrees of complexity depending on the amount of available data defining the original design. This initial investment in creating a representative model will bear fruit in the ability to quickly highlight pitfalls, manage design updates and perform “what-if” studies during the development phase. This enables the structure to evolve into an efficient and robust design while significantly increasing confidence levels to pass the final validation physical test. Speakers Pierre-Edouard Rousseau, Altair, on behalf of Transcal Rail

1. RAIL SEAT DEVELOPMENT USING
DYNAMIC CRASH SIMULATION
Pierre-Edouard Rousseau
30th September 2015

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Introduction

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Mesh creation
Dummy positioning & Instrumentation
FEA process
CAD import
Loadcase setup
Model Build
Post-processing

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Test/Simulation loadcase

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Dummy models

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Sled pulse

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Test example

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Safety forward event

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Injury post processing
Injury Criteria
GM/RT2
100
issue5
Injury Criteria
GM/RT2100
issue5
Head Resultant
Acceleration
80g
(3ms)
Chest deflection 63mm
Head Injury
criteria
500
(HIC15)
Chest V*C 1.0 ms-1
Neck Bending
moment
Flexion
310Nm
Femur Peak
Force LH & RH
5.7kN
(4.0kN for
TI >1.0)
Neck Bending
Moment
Extension
-135Nm
Knee
Displacement
LH &RH
16mm
Neck Injury
Criteria (NIJ)
1
Tibia Index
Up/Low LH & RH
1.0 (1.3 for
FL <4.0kN)
Chest
Acceleration
60g
(3ms)
Tibia Axial Load
LH & RH
8.0kN

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Injury post processing

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Injury post processing

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Integrity rearward event

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Integrity post processing

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Concept design
Baseline simulation
for each loadcase
Design changes discussed
with customer
Engineered feasible
SolutionUpdated CAD
Updated FE Model
Iterative Simulations
to Improve
Performance
Optimisation

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Simulation driven design benefits
 Offers a time and cost effective solution compared to prototype build and physical
testing.
 FE model with various possible degrees of complexity.
 Allows detailed interrogation of results not normally possible with physical testing.
 High number of iterations possible due to short simulation time.
 Quick feedback on alternative solution possible.
 Possible implementation early in the engineering process.
 No need to « re-test » for sign-off if small changes are later implemented.
 High level of confidence before sign-off with physical testing.

16. Thank you for your attention