Enhancement of Vehicle Safety and Improving Vehicle Yaw Behaviour Due to Offset Collisions Using Vehicle Dynamics

This study aims to optimise Vehicle Dynamic Control Systems (VDCS) in offset impact for vehicle collision mitigation. A proposed unique 3-D full-car mathematical model is developed and solved numerically to carry out this analysis. In this model, vehicle dynamics is studied together with the vehicle crash structural dynamics. Validation of the vehicle crash structure of the proposed model is achieved to ensure that the modelling of the crumple zone and the dynamic responses are reliable. It is demonstrated from the numerical simulations that the vehicle dynamic responses are captured and analysed and the influence of VDCS is determined accurately. In addition, it is shown that the mathematical model is flexible, useful and can be used in optimisation studies

The influence of Vehicle Dynamics Control System on the Occupant’s Dynamic response during a Vehicle collision

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

Performance Analysis of Hybrid and Full Electrical Vehicles Equipped with Continuously Variable Transmissions

The main aim of this paper is to study the potential impacts in hybrid and full electrical vehicles performance by utilising continuously variable transmissions. This is achieved by two stages. First, for Electrical Vehicles (EVs), modelling and analysing the powertrain of a generic electric vehicle is developed using Matlab/Simulink-QSS Toolkit, with and without a transmission system of varying levels of complexity. Predicted results are compared for a typical electrical vehicle in three cases: without a gearbox, with a Continuously Variable Transmission (CVT), and with a conventional stepped gearbox. Second, for Hybrid Electrical Vehicles (HEVs), a twin epicyclic power split transmission model is used. Computer programmes for the analysis of epicyclic transmission based on a matrix method are developed and used. Two vehicle models are built-up; namely: traditional ICE vehicle, and HEV with a twin epicyclic gearbox. Predictions for both stages are made over the New European Driving Cycle (NEDC).The simulations show that the twin epicyclic offers substantial improvements of reduction in energy consumption in HEVs. The results also show that it is possible to improve overall performance and energy consumption levels using a continuously variable ratio gearbox in EVs

A novel method for tizanidine hydrochloride determination in aqueous solution based on fluorescence quenching of functionalised CdS quantum dots as luminescent probes

A novel, sensitive and convenient method for the determination of tizanidine hydrochloride (TZD) based on the fluorescence quenching of thioglycolic acid-capped CdS quantum dots (TGA-CdS QDs) is proposed. Luminescent CdS semiconductor quantum dots modified by thioglycolic acid were synthesized from cadmium nitrate and sodium sulfide in alkaline aqueous solution. The modified CdS QDs are water-soluble, stable and highly luminescent. When TZD was added into the CdS QDs colloidal solution, the surface of CdS QDs generates the electrostatic interaction in aqueous medium, which induces the quenching of fluorescence emission at 518 nm upon excitation at 340 nm. Under the optimal conditions, the Stern-Volmer calibration plot of F­ο/F against concentration of TZD was linear in the range of 3.0-18.0 μg/mL with a correlation coefficient of 0.9953. The detection limit was 1.35 μg/mL. The relative standard deviation for five determinations of 9 μg/mL TZD was 2.29%. The proposed method was successfully applied to commercial tablets with satisfactory results. The results were found to be in good agreement with those obtained by the reference method. The possible fluorescence quenching mechanism for the reaction is also discussed

Integration of Vehicle Dynamics Control Systems with an Extendable Bumper for Collision Mitigation

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 analysinganew vehicle dynamics/crash mathematical model and a multi-body occupant mathematical model. The firstmodel integrates a vehicle dynamics model with the vehicle’s front-end structure to define the vehicle’sbody crash kinematic parameters. In this model, the anti-lock braking system (ABS) and the active suspension control system (ASC) are co-simulated, 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 totraditional 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 bumperisused. It is also shown that the VDCS can affect the crash characteristics and the occupant safety positively,whereasthe rotations angle and acceleration of the occupant chest and head are significantly reduced

Effect of composite beam action on the hysteretic behavior of fully-restrained beam-to-column connections under cyclic loading

This paper assesses the composite beam effects on the hysteretic behavior of fully-restrained beam-to-column connections as part of steel moment-resisting frames (MRFs) designed in highly seismic regions. A practical approach is developed based on available experimental data to simulate the hysteretic behavior of composite beams including the effects of assymetric deterioration of the beam flexural strength and stiffness. A system-level analytical study is then performed that evaluates the collapse resistance of steel frame buildings designed with steel MRFs including the composite beam effects. It is demonstrated that when steel MRFs are designed with a SCWB ratio larger than 1.5 a tolerable probability of collapse is achieved over the life cycle of the steel frame building. It is also shown that controlled panel zone yielding can be achieved while reducing the required number of welded doubler plates in beam-to-column panel zone joints

Stability Requirements of Deep Steel Wide-Flange Columns under Cyclic Loading

Just recently, valuable experimental data that characterized the hysteretic behavior of deep wide-flange steel columns (i.e., column depth, d >16 inches) at full-scale became available. Such members are typically used in steel moment-resisting frames (MRFs) in North America. In order to expand the findings of the experimental program, an extensive parametric study is conducted using a validated continuum finite element (FE) modeling approach. The nonlinear behavior of more than 40 steel wide-flange cross-sections is investigated. Each steel column is subjected to a monotonic, a symmetric cyclic, and a collapse-consistent lateral loading protocol coupled with different levels of constant compressive axial load ratios. Based on the FE results, the cyclic deterioration in the column flexural strength and stiffness is evaluated. Accordingly, design recommendations are developed related to the seismic compactness criteria for highly ductile members such that column axial shortening can be reduced under design basis and low-probability of occurrence earthquakes. The range of out-of-plane force demands is also evaluated for the lateral bracing design of columns in steel MRFs. In that respect, the current AISC provisions are evaluated. Empirical equations are developed for predicting the out-of-plane force demands and the plastic hinge length in steel wide flange columns

Seismic Design Criteria for Steel Moment Resisting Frames for Collapse Risk Mitigation

This paper quantifies the lateral overstrength and the collapse risk of steel buildings with perimeter special moment frames (SMFs) designed in highly seismic regions in North America. State-of-the-art analytical models that consider the contributions of the composite concrete slab and the interior gravity framing to the lateral resistance and strength of steel frame buildings are employed. The findings demonstrate that the quantification of system overstrength based on dynamic analysis is more appropriate to nonlinear static analysis, since dynamic amplification of story shear forces due to higher mode effects is considered. Collapse risk is quantified using the mean annual frequency of collapse. It is found that low to mid-rise SMFs designed with a strong column weak-beam (SCWB) ratio larger than 1.0, achieve a probability of collapse larger than 1 percent in 50 years. A tolerable probability of collapse is achieved when a SCWB > 1.5 is implemented into the seismic design of steel SMFs