Body Structure Strength Of Sleeper Coaches During Rollover Test As Per AIS 119
To be published on November 21, 2019 by SAE International in United States
Event: NuGen Summit
Bus passenger safety has always been a concern considering various impacts like side impact, front impact, rollover etc. happening in real life scenarios. Various standards have been formulated for simulating these conditions and with respect to rollover, standards like ECE-R66 are being used to understand the superstructure strength. In India, we have AIS-052 (bus body code) and AIS-031 specific for bus rollover testing. AIS-119 has been published for rollover testing of sleeper coaches with modifications in the survival space creation in sleeper coaches for berths. With physical testing being more expensive, CAE simulations are being considered as vital option which also helps in design modification in a lesser time. This paper discusses the scope of numerical simulation of sleeper coach rollover using an explicit dynamic solver RADIOSS to understand the structure deformations, survival space clearances/intrusions. The paper will describe the procedure for the numerical simulation starting from the CAD development, geometry clean up, meshing techniques, element formulations, CG measurement, input deck set up till the post processing of results. In order to validate the numerical simulation, critical bus joints have been identified for the physical testing and the same has been replicated in the joint level simulation to validate the various joint stiffness. A physical test on a bay section is also performed for numerical validation of the results. After finalization of base model, structure is being redesigned with focus on light weighting with respect to material and structural member cross-sections. The paper will conclude with the results , conclusions and interpretations of the rollover simulation, identification of critical zones and understanding of energy balance of the system.