Analysis of vehicle rollover using multibody dynamics

This study reports on the analysis of vehicle deformation due to rollover using multi-body dynamics which enables estimating motions of rigid bodies subjected to external forces. For the vehicle rollover analysis using the ADAMS, we have developed a FEA-based numerical vehicle model consisting of a rigid lower body and a deformable upper body. Here, comprehensive analysis of the static and dynamic roof strength resistance of a vehicle using our prediction model is described. We obtain the displacement of A-pillar top-end of a vehicle for each of the static and dynamic tests according to the FMVSS 216 protocol and the Controlled rollover impact system (CRIS) condition, respectively. The displacement of A-pillar top-end represents the roof intrusion causing injuries for passengers in the front seats, thereby evaluating the Strength to weight ratio (SWR) of a vehicle.

     

Plastic mechanism analysis of concrete-filled double-skin (SHS inner and SHS outer) stub columns

A plastic mechanism to predict the collapse behaviour of concrete-filled double-skin stub columns is developed and analysed in this paper. Both outer and inner tubes are square hollow sections (SHS). In the analysis, the inner tube is treated the same way as that used in previous research on empty SHS stub columns. New mechanism models are developed for the outer tubes. The effect of local buckling in the outer tube is also studied. The concrete model adopted in this paper considers the effect of confinement of the concrete induced by the double skin tubes. It also considers the strength degradation of concrete for large deformation analysis. It has been found that the effect of local buckling on the collapse curve of the outer tube can be ignored. The concrete model including confinement and strength degradation should be used in order to simulate the collapse behaviour, especially for thin outer tubes. Good agreement was achieved between the plastic mechanism analysis and experimental results.