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EnginSoft - CAE Conference Abstracts
EnginSoft International Conference 2011 |
Advanced CAE Design for Increasing Railway Vehicles Fire Safety Level |
F. Chiti - Ansaldo Breda (Italy) |
Abstract |
In designing a railway vehicle, fire safety is one of the high priorities in view of the volume of passengers being transported. It is even more vital if the system is built underground as fire incident in an underground train way is considerably different from fire in a building in term of fire development, evacuation and rescue operations. Fire safety approaches are always challenging because they involve physically complex and domain dependent events. A technical team is been constituted by AnsaldoBreda and EnginSoft for realizing a ambitious project that foresees to develop a new methodological procedure for the fire safety prediction in complex mechanical structures using analytical approaches and numerical simulations. The methodology adopts, as input, results from standard tests for material certification and it permits to predict with accuracy system fire response at design phase level. The methodology, based on advanced CAE and Virtual Prototyping procedures, is developed for increasing fire safety level supporting either design choices (e.g. fire retardant materials applications) or hazard assessment decisions (i.e. define safety levels). Hazard assessment is a process for estimating the potential severity of the fires that can develop under defined scenarios, once defined incidents have occurred: the prediction of the fire scenario is a qualitative, quantitative, time-sequence-based description of the fire incident, identifying key aspects that characterize the event and differentiate it from other possible situations. It requires an evaluation of a complete design that addresses certain fire safety objectives and therefore it needs to recognize most probable fire scenarios. Decode any potential fire scenario specifications into a description of the fire characteristic, i.e. materials fire-testresponse behaviour, rate of heat release, rate of mass loss, total heat release, flame spread, etc., it’s the main technical challenge. Different methods and models are available in literature for predicting fire phenomena related to fire hazard assessment in safer system design. Correlations between different techniques are not easy and straight, because often based on coded experimental data and/or accident investigations. This activity proposes an approach to investigate fire scenarios by considering contemporary different methods and tools for performing fire hazard assessment for products, assemblies and/or complete vehicles in railway application area. An innovative computer aided multidisciplinary procedure, managed by modeFRONTIER, able to compare and/or to combine different approaches and to amplify their own capabilities in fire design prediction is created and a comparison between predictions and complete metro train wagon subjected to full scale experimental tests for verifying its fire reaction behavior results is shown. |
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