This paper focuses on state of charge (SOC) dependent mechanical failure analysis of 18650 lithium-ion battery to detect signs of thermal runaway. Quasi-static loading conditions are used with four test protocols (Rod, Circular punch, three-point bend and flat plate) to analyse the propagation of mechanical failures and failure induced temperature changes. Finite element analysis (FEA) is used to model single battery cell with the concentric layered formation which represents a complete cell. The numerical simulation model is designed with solid element formation where stell casing and all layers followed the same formation, and fine mesh is used for all layers. Experimental work is also performed to analyse deformation of 18650 lithium-ion cell. The numerical simulation model is validated with experimental results. Deformation of cell mimics thermal runaway and various thermal runaway detection strategies are employed in this work including, force-displacement, voltage-temperature, stress-strain, SOC dependency and separator failure. Results show that cell can undergo severe conditions even with no fracture or rupture, these conditions may slow to develop but they can lead to catastrophic failures. The numerical simulation technique is proved to be useful in predicting initial battery failures, and results are in good correlation with the experimental results.

The aim of this paper is to enhance crashworthiness in the case of vehicle-to-barrier full frontal collision using vehicle dynamics control systems integrated with an extendable bumper. The work carried out in this paper includes developing and analysing a new vehicle dynamics/crash mathematical model and a multi-body occupant mathematical model. The first model integrates a vehicle dynamics model with the vehicle's front-end structure to define the vehicle's body crash kinematic parameters. In this model, the antilock braking system (ABS) and the active suspension control system (ASC) are cosimulated, and its associated equations of motion are developed. The second model is used to capture the occupant kinematics during full-frontal collision. The numerical simulations show that in the case of using the extendable bumper, the crash energy absorbed is considerable compared to traditional structure. Therefore, the minimum vehicle crumble zone's deformation is obtained when the ABS alongside under pitch control (UPC) is applied with the extendable bumper. The minimum pitch angle of the vehicle body and acceleration are obtained when the ABS alongside UPC technique is applied without the extendable bumper. The occupant deceleration and the occupant's chest and head rotational acceleration are used as injury criteria. The longitudinal displacement and acceleration of the occupant is extremely decreased when the extendable bumper is used. It is also shown that the VDCS can affect the crash characteristics and the occupant safety positively, whereas the rotations angle and acceleration of the occupant chest and head are significantly reduced.

This paper aims to apply a vehicle dynamics control system to mitigate a vehicle collision and to study the effects of this systems on the kinematic behaviour of the vehicle's occupant. A unique three-degree-of-freedom vehicle dynamics-crash mathematical model and a simplified lumped-mass occupant model are developed. The first model is used to define the vehicle body's crash parameters and it integrates a vehicle dynamics model with a model of the vehicle's front-end structure. In this model, the anti-lock braking system and the active suspension control system are co-simulated, and the associated equations of motion are developed. The second model aims to predict the effect of the vehicle dynamics control system on the kinematics of the occupant. The Lagrange equations are used to solve that model owing to the complexity of the obtained equations of motion. It is shown from the numerical simulations that the vehicle dynamics-crash response and occupant behaviour can be captured and analysed quickly and accurately. Furthermore, it is shown that the vehicle dynamics control system can affect the crash characteristics positively and that the occupant's behaviour is improved.