Automotive Science and Engineering
Volume:13 Issue: 3, Summer 2023

This paper presents an experimental study on the effect of adhesive thickness on the maximum load of adhesive joints under static and impact loading, using the double cantilever beam (DCB) test method. The DCB specimens were prepared with varying adhesive thicknesses and subjected to impact loading using a drop weight impact tester. The maximum load was recorded for each specimen. The results indicated that the maximum load of the adhesive joints increases with increasing adhesive thickness up to 5 mm, beyond which the maximum load decreases with further increase in adhesive thickness. Moreover, the failure mode of the adhesive joint was found to be strongly dependent on the adhesive thickness, with thicker adhesive layers exhibiting an adhesive failure mode but in thinner thicknesses, the adhesive mode is cohesive. These findings provide important insights into the design and optimization of adhesive joints for applications that are subject to impact loading.

This paper presents an inhomogeneous lens to radiate a control-table Fan Shaped pattern for long-range automotive applications. Fan Shaped pattern of the designed lens covers more angles in azimuth. The proposed circular aperture inhomogeneous lens is designed based on the critical angle theorem. The profile of the dielectric constant of the proposed lens changes in 3 directions of ρ, φ, and z. The lens is matched to the source and surroundings. A closed-form formula is offered for an arbitrary fan-shaped pattern lens antenna. A compact circular lens with a diameter of 20 mm and thickness of 2.25 mm is simulated in CST full-wave software to validate the design structure.

This paper investigates the performance of the hydraulically interconnected suspension system with the full vehicle model of ride and handling. A sensitivity analysis has been performed by changing the coefficients of the cylinder and accumulator valves and the initial conditions of the accumulators in the default hydraulic circuits to determine the effect on the frequency and damping of the system response such as roll, pitch, and bounce. This study highlights the importance of the influence of all system parameters to investigate vehicle vibration characteristics. The results provide valuable insights for designers and engineers working on improving automotive suspension system performance. Damping and frequency of modes change up to 179% with the change of cylinder valves and 141% with the change of accumulator valves and 74% for the initial pressure of accumulators change in mentioned range.

In this research, the effect of using three Nano fluids contains graphene oxide (GO), titanium oxide (TiO2) and aluminum oxide (Al2 O3) was analyzed on the heat transfer of the car radiator by experiment in physical conditions on the car engine. Distilled water and ethylene glycol (60:40) as the base fluid was companied with three nanoparticles contain graphene oxide, titanium oxide and aluminum oxide that each one separately with 0.1, 0.2 and 0.3 weight percent and flow rates of 10, 20, 32 and 40 liters per minute were used at normal engine temperature. After the temperature of the radiator cooling fluid reached 90 degrees Celsius and the fan was turned on for one minute, the results showed that increasing the weight percentage of nanoparticles to the base fluid increases the displacement heat transfer coefficient and most increase in the coefficient of heat transfer at 0.3 weight percent to an approximate value of 5.2% in aluminum oxide, 11.9% for titanium oxide and 28.7% for graphene oxide compared to the base fluid was received. With the increase in weight percentage, the pressure drop and Nusselt number increased.  The highest percentage increase in the radiator pressure drop for all three Nano fluids with 0.3 weight percentage and 2.2% for   aluminum oxide, 3.5% for Titanium oxide and 5.24% for graphene oxide were received.

This study examines the impact of a fuzzy logic-based control strategy on managing peak power consumption in the auxiliary power unit (APU) of a hybrid electric bus. The APU comprises three components: an air compressor, a power steering system, and an air conditioning system (AC) connected to an electric motor. Initially, these components were simulated in MATLAB-SIMULINK software. While the first two were deemed dependent and independent of vehicle speed, respectively, the stochastic behavior of the steering was emulated using the Monte Carlo method. Subsequently, a fuzzy controller was designed and incorporated into the APU to prevent simultaneous operation of the three accessories as much as possible. The results of repeated simulations demonstrated that the designed fuzzy controller effectively distributed the operation of the accessories throughout the driving cycle, thereby reducing overlaps in auxiliary loads. Consequently, the APU's average and maximum power consumption exhibited significant reductions. Furthermore, through multiple simulations with an upgraded power system model integrating the new APU-controller package, it was established that the proposed strategy for managing auxiliary loads in the bus led to lower fuel consumption and emissions.

In this article, the optimal robust H2 / H∞ control of self-driving car platoons (SDCPs) under external disturbance is investigated. By considering the engine dynamics and the effects of external disturbance, a linear dynamical model is presented to define the motion of each self-driving car (SDC). Each following SDC is in direct communication with the leader. By utilizing the relative position of following SDCs and the leader, the error dynamics of each SDC is calculated. The particle swarm optimization (PSO) method is utilized to find the optimal control gains. To this aim, a cost function which is a linear combination of H2 and H∞ norms of the transfer function between disturbance and target variables is constructed. By employing the PSO method, the cost function will be minimized and therefore, the robustness of the controller against external disturbance is guaranteed. It will be proved that under the presented robust control method, the negative effects of disturbance on system performance will significantly reduce. Therefore, the SDCP is internally stable and subsequently, each SDC tracks the motion of the leader. In order to validate the proposed method, simulation examples will be presented and analyzed.