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For (benchmark) tests it is not only useful to study the acoustic performance of the whole vehicle, but also to assess separate components such as the engine. Reflections inside the engine bay bias the acoustic radiation estimated with sound pressure based solutions. Consequently, most current methods require dismounting the engine from the car and installing it in an anechoic room to measure the sound emitted. However, this process is laborious and hard to perform. In this paper, two particle velocity based methods are proposed to characterize the sound radiated from an engine while it is still installed in the car. Particle velocity sensors are much less affected by reflections than sound pressure microphones when the measurements are performed near a radiating surface due to the particle velocity's vector nature, intrinsic dependency upon surface displacement and directivity of the sensor. Therefore, the engine does not have to be disassembled, which saves time and money.

This Study describes about the development of new concept' rear wheel guards for the reduction of Road Noise in the passenger vehicles. The new wheel guards are proposed by various frequency chamber concept and different textile layers concept. Two wheel guards were verified by small cabin resonance and vehicle tests. Through new developing process without vehicle test, Result of road noise will be expected if this concepts and materials of wheel guard are applied into automotive vehicle. As this concept consider tire radiation noise frequency and multilayers sound control multilayers, 2 concepts reduced road noise from 0.5 to 1.0dB. The proposed method of part reverberant absorption is similar to results of vehicle tests by part absorption index. Furthermore, optimization of frequency band in wheel guards will reduce more 0.5 dB noises. As a result of the application of Aimed Helmholtz and Multilayers concept, this paper classifies reduction of the road noise, cost and weights.

Impact resistance of plastic underbody parts was studied using simulated injection-molded specimen which can be tested according to different types of material used, injection molding variants like position and number of injection molding gates, and features of ribs. Material applied was glass fiber reinforced polyamide which can be used in underbody parts. Test was performed using several combinations of injection molding gates and rib types. From the test result, optimal design guide for plastic underbody parts was determined. Also, new high impact resistant plastic material made of glass fiber reinforced polyamide 66 (PA66) and polyamide 6 (PA6) alloy was developed and the material properties useful for CAE were determined. As a case study, oil pan and muffler housing were designed following the optimal design guide and CAE. And the reliability of the sample muffler housing designed was verified.

In this research, the influence of tire size and shape on sound radiation in the mid-frequency region was studied. First, the relationship between the structural wave propagation characteristics of a tire excited at one point and its sound radiation was identified by using FE and BE analyses. Then, by using that relationship, the effect of modifying a tire's aspect ratio, width and wheel diameter on its sound radiation between 300 Hz and 800 Hz was investigated. Finally, an optimization of the sound radiation was performed by modification of the tire structure and shape. It was found that most of a tire's structural vibration does not contribute to sound radiation. In particular, the effective radiation was found to occur at the frequencies where low wave number components of the longitudinal wave and the flexural wave first appear.

A new noble material for automotive bumper fascia has been developed by compounding of ethylene-propylene block copolymers with ethylene-α-olefin copolymers and some additives. Also mineral fillers are added, if necessary. This material is suitable for injection molding of large parts including automotive bumper fascia. By using selected rubbers which have proper melt viscosity, molecular weight, and co-monomer content, and adding modified polymer containing polar group, it has enhanced processibility and paintability maintaining general properties such as tensile strength, impact strength at low temperature, and thermal and UV stability. The remarkable characteristics of this material is good processibility compared to the conventional TPOs. This material has especially high melt flow index(20∼30g/10min at 230°C) and stable flow behavior at the processing conditions.

In this paper, the distortion analysis in spot welded area of car body - front side member, it is found out that the optimum condition for panel assembly is closely related to the welding sequence, location of clamping system, number, shape and welding force. The distortion resulting from welding sequence is minimized starting from the surroundings of the clamping system and in the way that the value of the welding force is from large to small. The MCP is determined from the positions inducing the minimum distortion in panel through calculating the deformation and reacting force of the panel. The welding force originating from the manufacturing tolerance of assembly is a critical design factor determining the welding sequence and the clamping system that yield minimum distortion in spot welding of body panel.

The tube hydroforming technology (THF) has been extensively used as auto-body structural members such as engine cradle, frame rail etc. in order to meet the urgent need of vehicle weight and cost reduction as well as high quality. In this paper we experimentally investigate the mechanical properties for hydroformed tubes with various bulging strains under the plane strain mode. Axial compression tests for hydroformed tubes are performed to investigate the collapse load and collapse absorption capacity through the collapse load-displacement curves. Moreover the collapse absorption capacities are compared and discussed between as-received, hydroformed, and press formed tubes. Results demonstrate that the hydroformed tubes show higher collapse absorption capability in comparison with the as-received tube and the press formed tube, because of its high yield strength due to strain hardening.

This paper presents a transient vibration analysis of a nonlinear full-vehicle. The full-vehicle model consists of a powertrain, a trimmed body, a drive line, and front and rear suspensions with tires. It is driven by combustion forces and runs on a road surface. By performing time-domain simulation, it is possible to capture nonlinear behavior of a vehicle such as preload due to gravitational force, large deformation, and material nonlinearity which cannot be properly treated in the conventional steady state analysis. In constructing a full-vehicle, validation process is essential. Validation process is applied with respect to the assembling sequence. The validation starts with component levels such as tires, springs, shock absorbers, and a powertrain, and then the full-vehicle model is constructed. Model validation is done in two aspects; one is model accuracy and the other is model efficiency.

An engineering strategy to develop a new 27-ton dump truck is introduced in the process of design and analysis. Main engineering concerns in development of the new dump truck are focused on reducing weight as much as 180kg without deteriorating structural strength and fatigue life of its upper body - deck and subframe. To achieve this goal, a stress analysis and a fatigue life prediction based on CAE technique are employed at the early stage of design process. A finite element model of the full vehicle was constructed for the strength analysis. Then the fatigue life was predicted through the strength analysis and an S-N curve of high strength steel. The S-N curve for welded structures made of high strength steel was used along with a prototype vehicle's endurance test in order to set strength targets. As a result, the upper body was successfully developed without any fatigue issues.

The main role of the connecting rod in the engine is to deliver the firing load to the crankshaft. In order to carry out successfully the function, it is need to grasp the rotating crankshaft and also to keep the good stiffness of the big-end of the connecting rod in acceptable ranges during engine operation. When the stiffness of the big-end is needed to be reinforced, in general, some geometric dimensions are simply increased without consideration of their complex effects on deformation. Sometimes the reinforced geometry causes negative effects on the stiffness. This paper focuses on the effect of geometric parameters on stiffness in the big-end structure of connection rod by using Taguchi method. It is found that the side flange is the most influencing parameters. The FEA simulated results are compared with experiments.

A module based IPS (Intelligent Power Switch) evaluation system is proposed in this paper. As the IPS is gradually replacing the conventional relay and fuses, the stability and reliability of power system depends more on these IPS. The proposed IPS evaluation system outperforms the conventional manual evaluation in terms of speed and efficiency. This paper will introduce the structure of hardware and software of the IPS evaluation system. The system is placed between the module and cable connector to evaluate the module in an operating car without changing the cables. The control and signal processing is carried out by personal computer which is connected to the evaluation system by USB (Universal Serial Bus). The load resistance can be switch from actual load to arbitrary value using relay circuitry and DC electric load controlled by GPIB (General Purpose Interface Bus). CAN (Controller Area Network) circuits were added to control the IPS mounted inside the module.

The thermoplastic automotive pulley has been developed and will be commercialized to high volume production that achieves cost saving and weight reduction over other automotive pulleys in the metal and thermosetting resin by Hyundai Motor Company. Design feature incorporated in this automotive pulley allow it to be manufactured and assembled onto the water pump more efficiently in consequence of design integration with the water pump and power steering pulley. However, the harsh environment and dynamic loads that the thermoplastic pulley has to withstand required extensive CAE analysis and testing of the molded parts and the standard glass reinforced PA was selected for the application to maximize cost savings. The key aspects of the plastic automotive pulley as well as its advantage are presented.

A new heat-resistant cast iron alloy has been developed for the exhaust manifolds of new passenger-car diesel engines. This development occurred because operating demands on exhaust manifolds have increased significantly over the past decade. These demands are due to higher exhaust gas temperatures resulting from tighter emission requirements, improved fuel efficiencies, and designs for higher specific engine power. These factors have led to much higher elevated temperature strength and oxidation resistance requirements on exhaust manifold alloys. Additionally, thermal fatigue that occurs directly as a result of thermal expansions and mechanical constraint has become an increasingly important issue. The research detailed in this paper focused on the optimization of the chemical composition of a Si-Mo ductile iron to improve the mechanical and physical properties for use in an engine exhaust manifold.

To achieve a mass goal and minimize the bell mouthing phenomenon of Passenger Air Bag Housing which takes place when the air bag is in explosive action and detrimental to the safety of passenger side because excessive canister bell mouthing may distort and crash the top surface of instrument panel, a study on the replacing process of a PAB housing to a different material and process was performed. The explosive action of current steel PAB housing was firstly analized to evaluate the reaction forces transferred through the PAB and find out the adaptable material for replacing process. Due to the properties among the die casting alloys, the AM60B alloy was chosen for our new material for PAB housing. Then, stress analysis by the finite element method was performed for a design modification of magnesium one piece housing.

The woofer in a car should be large to cover the low frequencies, so it is heavy and needs an ample space to be installed in a passenger car. The geometry of the woofer should conform to the limited available space and layout in general. In many cases, the passengers feel that the low-frequency contents are not satisfactory although the speaker specification covers the low frequencies. In this work, a thin panel is installed between the roof liner and the roof panel, and it is used as the woofer. The vibration field is controlled by many small actuators to create the speaker and baffle zones to avoid the sound distortion due to the modal interaction. The generation of speaker and baffle zones follows the inverse vibro-acoustic rendering technique. In the actual implementation, a thin acrylic plate of 0.53x0.2 m2 is used as the radiator panel, and the control actuator array is composed of 16 moving-coil actuators.

The controlled rolling process has been introduced to increase strength and toughness of alloy steels for the application of transmission gear. Cr-Mo alloy steel containing 0.02% Nb was controlled rolled in the temperature range of 870-970°C, showed fine austenite grain size, about ASTM No.11, resulted from the effects of recrystallization and Nb(C,N) precipitation. To investigate the effects of grain refinement on mechanical properties, several tests were conducted for the newly developed controlled rolled steel and conventional Ni-Cr-Mo alloy steel after carburizing. The new steel showed 2.1 times higher pitting resistance than the conventional steel. Fatigue limits of new and conventional steels were 950 and 930 MPa respectively. Charpy impact energy of new steel was improved about 35% compared with the conventional steel. Consequently, the pinion gear from the new steel instead of conventional one showed enhanced performance, especially pitting resistance, in dynamometer test.

The weight reduction of the car suspension parts has a direct influence on the ride and handling. However, the application of nonferrous metal materials, such as aluminum and magnesium, which results in a lighter weight of the suspension can lead to an increase in manufacturing costs compared to cast iron. In this study, vertical type high-pressure die casting using by electro-magnetic stirring (EMS) with A356 alloy in the sleeve was used to control the fine microstructure. Process optimization and part development, as well as unit product and automotive assessment were carried out for electro-magnetic stirring methods. Without making the slurry, the mechanical properties were obtained through optimization of process variables UTS 320MPa, YS 239MPa, EL 13.3%. It also succeeded in mass production with minimum cost increase of aluminum suspension components.

Hyundai's new engine is developed which optimize the cooling efficiency for knocking improvement and friction reduction. The cooling concepts for this purpose are 1) equalizing the temperature among cylinders by flow optimization, 2) cooling the required area intensively, 3) adopting ‘active flow control’ and 4) enlarging fuel economy at high speed range. In order to realize the cooling concept, 1) cross-flow, 2) compact water jacket & exhaust cooling, 3) flow control valve and 4) cylinder head with integrated exhaust manifold are considered. Improvement of knocking and friction reduction by increased cooling water temperature makes fuel efficiency possible. On the other hand, in order to strengthen the cooling around the combustion chamber and to reduce the deviation among the combustion chamber of cylinders, it is required to design the head water jacket shape accordingly.

A signal lamp performs a function to inform the position and behavior of the vehicle. And it represents a specific design identity of the vehicle or brand identity. Recently it implements the unique three-dimensional effect while using a LED. However, a number of LEDs and complex form of the lens shape have to be applied, so results in the size, weight, cost increase. In this study, the hologram technology that is an exemplary technique for implementing the described three-dimensional image is applied. With a hologram, it is possible to reproduce a complex shape three-dimensional image by using a hologram film. Therefore the number of parts can be reduced. And it is possible to copy the film has a mass production benefits.

In order to apply an effective noise reduction treatment determining the contribution of different engine components to the total sound perceived inside the cabin is important. Although accelerometer or laser based vibration tests are usually performed, the sound contributions are not always captured accurately with such approaches. Microphone based methods are strongly influenced by the many reflections and other sound sources inside the engine bay. Recently, it has been shown that engine radiation can be effectively measured using microphones combined with particle velocity sensors while the engine remains mounted in the car [6]. Similar results were obtained as with a dismounted engine in an anechoic room. This paper focusses on the measurement of the transfer path from the engine to the vehicle interior in order to calculate the sound pressure contribution of individual engine sections at the listener's position.