Study on the Building of Johnson-Cook Constitutive Model for Spot-welded Stainless Steel Materials for Cars and the Longitudinal Dynamic Carrying Capability of Carbody
In the collision analysis of conventional stainless steel metro cars,it's generally impossible to consider the strain rate effect of all materials of the carbody,and the analyses are mostly based on the speed conditions in EN 15227:2008 without considering the dynamic response of the carbody in high-speed condition,so the dynamic impact analysis is not complete.This article describes the quasi-static tensile test and the dynamic impact test at ambient temperature for the commonly used stainless steel materials for stainless steel metro carbody,completing the identification of Johnson-Cook constitutive parameters of the materials.It separately identifies the carrying limit values of the lead car and the intermediate car,compares and analyzes the influence of the strain rate effect,the coupler load and the impact speed on the carrying capability.The upper limit of the collision interface load is determined according to the longitudinal dynamic carrying limit of the carbody,and a step interface energy distribution pattern is proposed on taking into account the cost.The result shows:both the stainless steel SUS301L and the high-strength steel S500MC are strain rate sensitive materials and their dynamic carrying limits are affected by the strain rate effect and the impact speed.Determining the dynamic carrying limit of a single car can provide numerical reference for the energy distribution of couplers and draft gears of the train,and the use of step gradient interface distribution has a certain positive significance for improving the crashworthiness of the train.
stainless steel metro carJohnson-Cook constitutivedynamic carrying limitstrain rategradient energy distribution
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