Automotive Science and Engineering
Volume:7 Issue: 2, Spring 2017

Automotive design engineers face the challenging problem of developing products in highly competitive markets. In this regard, using conceptual models in the first step of automotive development seems so necessary. In this paper, to make a body in white conceptual model, an engineering approach is developed for the replacement of beam-like structures, joints, and panels in a vehicle model. The proposed replacement methodology is based on the reduced beam, joint, and panel modeling approach, which involves a geometric analysis of beam member cross-sections and a static analysis of joints. In order to validate the proposed approach, an industrial case-study is presented. Two static load cases are defined to compare the original and the concept model by evaluating the stiffness of the full vehicle under torsion and bending in accordance with the standards used by automotive original equipment manufacturer (OEM) companies. The results show high accuracy of the concept models in comparison with the original model in bending and torsional stiffness prediction.

This paper presents finite element analysis (FEA) of a coated and uncoated cylinder heads of a diesel engine to examine the distribution of temperature and stress. A thermal barrier coating system was applied on the combustion chamber of the cylinder heads, consists of two-layer systems: a ceramic top coat (TC), made of yttria stabilized zirconia (YSZ), ZrO2-8%Y2O3 and also a metallic bond coat (BC), made of Ni-Cr-Al-Y. The coating system in this research comprises 300 μm zirconium oxide TC and 150 μm BC. The three-dimensional model of the cylinder heads was simulated in abaqus software and a two-layer viscoplasticity model was utilized to investigate the elastic, plastic and viscous behavior of the cylinder heads. The elastic and plastic properties of BC and TC layers were considered and the effect of thermal barrier coatings on distribution of temperature and stress was investigated. The aim of this study is to compare the distribution of temperature and stress in the coated and uncoated cylinder heads under thermo-mechanical loads. The results of FEA showed that the thermal barrier coating system reduces the temperature about 53°C because of its lower thermal conductivity. As a result, the cylinder head tolerates lower temperature and fatigue life will increase. The results of thermo-mechanical analysis indicated that the stress in the coated cylinder head decreased approximately 24 MPa for the sake of depletion of temperature gradient which can lead to higher fatigue lifetime. Viscous strain was significant and its amount is not negligible.

This article investigates the effects of using a thin-walled structure in the chassis front rails in the automotive industry. In frontal accidents, the front rails of the vehicle chassis, increases vehicle crash-worthiness and occupants’ safety by plastic deformation, energy absorption, increasing the crash duration and reducing the load and injuries to the occupants. The objective is to optimize the thin-walled structure of the bumper and the direct beams in the front chassis rails. An explicit FEM full vehicle model with a dummy, safety belts, and air bags are used for the modeling and analysis of the applied loads on the vehicle and the occupants. The FMVSS No. 208 and ECE No. 94 standards are considered for the simulation of a vehicle accident. Finally, the proper model will be selected based on the results.

Recent evolutions in World Trade Organization (WTO) and other international trading agreements have made industries all around the world face a new era of intense global competition. Simultaneously with increased competitive pressure, permanent development and innovation comprise building blocks of firm excellence. In a dynamic environment, failure to innovate ends up with business stagnation and getting out of the competition ring. Technological innovation capability is a complex, elusive and uncertain concept, which have made it difficult to characterize. Measuring technological innovation capability requires considering numerous qualitative and quantitative criteria at the same time. One of the main factors hindering the success of adopting technological innovation to attain competitive advantage by firms in developing countries is lack of awareness about and recognition of the level of firm technological capabilities and how to use them to acquire relative advantages. Evaluation of technological capability serves as a tool for identifying the required capabilities to implement the firm technological priorities. Based on a wide spectrum of available literature, the present paper attempts to extract criteria related to technological innovation capabilities in the field of turbocharging technology. These criteria were then provided to a group of experts in automotive industry, so as to identify the desired level of technology for turbocharging technology in automotive industry. On the other hand, by restricting items of the questionnaire based on the experts’ opinions, the current state of turbocharging technology capabilities was identified, based on which technological gap in each criterion under study was determined. On the other hand, once the technological gap was identified, improvement projects were defined to either suppress or eliminate the gap.

In automotive industry, foam-filled structures have aroused increasing interest because of lightweight and capacity of energy absorption. Two types of foam filled thin walled structures such as the uniform foam filled (UF) and the functionally graded foam (FGF). To improve crashworthiness performance, FGF are used to fill structures, unlike existing uniform foam materials. In addition, by seeking for an optimal design systematically, some computational optimization signifies a more effective tool to find the best crashworthiness design of structures,. This paper will an exhaustive review of the previous studies of simulation-based optimization such as metamodels, objective functions, design variables, design of experiments, optimization techniques of crashworthiness of tubes.

Heat transfer in internal combustion engines is one of the most significant topics. Heat transfer may take place through thermal conduction and thermal convection in spark ignition engines. In this study, valve cover heat transfer and thermal balance of an air-cooled engine are investigated experimentally. The thermal balance analysis is a useful method to determine energy distribution and efficiency of internal combustion engines. In order to carry out experiments, a single cylinder, air-cooled, four-stroke gasoline engine is applied. The engine is installed on proper chassis and equipped with measuring instruments. Temperature of different points of valve cover and exhaust gases is measured with the assistance of K-type thermocouples. These experiments are conducted in various engine speeds. Regarding to the first law of thermodynamics, thermal balance is investigated and it is specified that about one-third of total fuel energy will be converted to effective power. It is also evaluated that for increasing brake power, fuel consumption will increase and it is impossible to prevent upward trends of wasted energies. In addition, it is resulted that, there is a reduction heat transfer to brake power ratio by increasing engine speed. Furthermore, it is found that, at higher engine speed, lower percentage of energy in form of heat transfer will be lost.