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Numerical durability analysis is the only approach that can be used to assess the durability of vehicles in early stages of development. In these stages, where there are no physical prototypes available, the road wheel forces (or spindle forces) for durability testing on Belgian PG (Proving Ground) must be predicted by VPG (Virtual Proving Ground) or derived from the measured forces of predecessor vehicles. In addition, the tuning parts and geometry are not fixed at these stages. This results in the variation of spindle forces during the development stages. Therefore, it is not reasonable to choose the forces predicted at a specific tuning condition as standard forces. It is more reasonable to determine the standard forces stochastically using the DB of the measured forces of predecessor vehicles. The spindle forces measured or predicted on Belgian PG are typically stationary random.

An investigation has been performed to study the response of the front bumper beam of automobiles subjected to an external impact load. In the investigation, an aluminum shell structure is modeled as a beam, and the energy absorber of polyurethane is also modeled as statically equivalent springs attached to the beam. Castigliano's second theorem and principles of energy and momentum are then used to calculate the reaction forces and maximum deflection. Stress distribution is then calculated using the beam theory. The primary concern of the investigation is to present a procedure of how to design optimally the cross-sectional shape of the front bumper of automobiles.

In this paper, a design procedure for the optimized light weight front cross member, which is a sub frame of the car chassis, without sacrificing basic functional requirements is presented. As the first step, optimal structural integrity was calculated and extracted using a CAE technique with the available volume constraint of the package layout. Quantitative design loads for the cross member was achieved by measurement. Dynamic load analysis using ADAMS was also performed to determine the loads. Later, these calculated loads were applied to the FEM stress analysis of the cross member. Furthermore, durability analysis was also performed using load profile database measured from ‘Hyundai Motor Co. Proving Ground’. Four constant amplitude durability tests and two static tests were performed on the cross member prototypes to confirm design reliability.

Air conditioning is defined as the process of treating air so as to control simultaneously its temperature, humidity, cleanliness and distribution to meet the requirements of the conditioned space. As in the definition, the important actions involved in the operation of an air conditioning system are temperature and humidity control, air purification and movement. For these conditions this paper proposes a Automatic Climate Control(ACC) system of the bus. The system has cooling, heating, and dehumidifying modes, and is governed by dual 8-bit microprocessors. These modes are broken down into sub-modules dealing with control of the compressor, blower speed, damper position, air purifier, ventilators, preheater, air mixing damper and so on.

The verification of the durability for vehicle body and chassis components is a basic requirement for the vehicle development process. For this, automotive company performs durability test on the proving ground or predict the durability using CAE technology. The representative proving ground test that verifies the durability of vehicle body and chassis components are belgian(hereinafter B/G) and cross-country(hereinafter X/C) test road. The B/G test road verifies the durability of body and chassis components for periodic road load that the vehicle undergoes while travelling on a rough road with regular speed. The X/C test road is composed of squat, dive, bumping and bottoming test modes and this test verifies the durability under aperiodic road load. Because of the relatively long test load of X/C, the road load signal of X/C is too long and enormous to apply it to durability analysis.

Ground systems in automobiles become more important as more electric devices are installed and the amount of currents flowing increases. The performance of the devices depends on the ground voltage, which is generated between ground points by I-R voltage drops. Therefore, low ground voltages are required for the reduction of the unnecessary power dissipation as well as the reliable performance of the devices. In this paper, we propose an automotive ground system model to analyze ground structure and reveal the main cause of ground voltages. The equivalent resistor network model is presented to describe the relationship between ground points. Then, we validate the model by comparing the simulation results with the measurements in a real car. The presented analysis can provide guidance on designing a reliable ground system such as how to reduce the ground voltages for the proper operation of devices.

Invisible Passenger-side Airbag (IPAB) door systems must be designed with a weakened area such that the airbag will break through the Instrument Panel (IP) in the intended manner, with no flying debris at any temperature. A predictive Finite Element Analysis (FEA) was carried out to calculate the effects of varying design factors (the length and thickness of kink-hinge, tear-line type and temperature) on the IPAB-door opening. The impact performance of plastic parts was considered, because the mechanical properties of thermoplastic materials are strongly dependent on strain rate.

In order to meet FMVSS 201 (U) requirements, the upper vehicle interior structures with trim in a vehicle need to be properly designed to minimize injuries when head impacts these components. This paper presents a study of countermeasures in pillars using FEA approach by considering some design factors. Optimal designs are then selected for interior head impact protection based on CAE analysis using LS-DYNA non-linear finite element code.

Voice Recognition (VR) systems have become an integral part of the infotainment systems in the current automotive industry. However, its recognition rate is impacted by external factors such as vehicle cabin noise, road noise, and internal factors which are a function of the voice engine in the system itself. This paper analyzes the VR performance under the effect of two external factors, vehicle cabin noise and the speakers’ speech patterns based on gender. It also compares performance of mid-level sedans from different manufacturers.

Aluminum steering knuckles are widely employed for weight reduction and improvement of ride & handling performance. In this study, a high strength aluminum alloy for cast-forged knuckle was designed to achieve higher mechanical properties than those of the conventional foundry alloy. Using this alloy, high strength knuckles were manufactured and performed test of mechanical properties, suspension module strength and durability. The strength and the elongation of the developed knuckle were increased by 20% and 40%, respectively, as compared with the conventional alloy. Also this knuckle passed the static strength and durability test of the front suspension module.

Customer vehicle usage monitoring is one of the most fundamental elements to consider in the process of developing a durable vehicle. The extant method to research customer vehicle usage takes considerable time and effort because it requires attaching a series of sensors to the vehicle-gyroscope, accelerometer, microphone, and GPS-to gather information through data logs and then to analyze data in a computer where designated analyzing software has been installed. To solve the problem, this paper introduces a new concept of integrated system developed to examine customer vehicle usage that can analyze data by collecting it from a variety of sensors installed on a smartphone.

This report explains the basic theory of designing the accelerating durability test road and the role of each factors contributing to the test road surface profile. Also this road is designed by considering the charactors of vehicle suspension system and conditions of driving. In test road, the factors affecting to the vehicle structural durability are correlation among surface shape of road profile, frequency of vehicle suspension system,distribution of axle twist angle and vibration of road profile height. Road PSD magnitude and frequency delay is used to control these factors relation.

In this research, an optical system for the detection of the flame propagation under the non-knocking and knocking conditions is developed and applied to a mass produced four cylinder SI engine. The normal flames are measured and analyzed under the steady state operating conditions at various engine speeds. For knocking cycles, the flame front propagations before and after knock occurrence are simultaneously taken with cylinder pressure data. In non-knocking and knocking cycles, flame propagation shows cycle-by-cycle variations, which are quite severe especially in the knocking cycles. The normal flame propagations are analyzed at various engine speeds, and show that the flame front on the exhaust valve side becomes faster as the engine speed increases. According to the statistical analysis, knock occurence location and flame propagation process after knock can be categorized into five different types.

Tie down loading effect on the car body has been analyzed for various factors. Excessive force during transportation causes local failure or dent of a car body. In order to prevent local failure and to increase the tie down strength effectively, nonlinear finite element analysis was performed considering large deformation, rotation and elasto-plastic deformation. Location of dent was predicted which was the same as reported and it was found that there are two ways to increase the tie down strength: one is the application of the tie down load at the side of fuel inlet and the other is the reinforcement of rear floor side member. This paper demonstrates the displacement and the stress distributions for various locations and directions of tie down loading and the degrees of reinforcement of rear floor side member.

This paper describes Hyundai's research and development work on a flexible fuel vehicle (FFV). The work on FFV has been conducted to evaluate its potential as an alternative to the conventional gasoline vehicle. Hyundai FFV described here can operate on M85, gasoline, or any of their combinations, in which the methanol concentration is measured by an electrostatic type fuel sensor. For that operation, a special FFV ECU has been developed and incorporated in the FFV. The characteristics affecting FFV operation, such as FFV ECU control strategy and injector flow rate, have been investigated and optimized by experiment. Various development tests have been performed in view of engine performance, durability, cold startability, and exhaust emissions reduction. The exhaust gas aftertreatment system being consisted of manifold type catalytic converter(MCC) and secondary air injection system has shown good emission reduction performance including formaldehyde emission.

It is necessary for vehicle horns not only to satisfy regulations on the sound level but also to fulfill various demands related with sound quality. For example, a disk type horn which is attached on most of small size vehicles has been required to improve its sharp feeling sound. However, the improvement of horn sound has been deterred mainly due to the deficiency of the understanding on how design factors are related with emotional judgments on horn sound. In addition, a proper CAE tool is not available in the process of horn design since it is difficult to describe multi-physical phenomena engaged with horns. The purpose of this study is to improve the sound quality of a disk type horn. In order to achieve this goal, firstly, acoustic characteristics of horns were obtained through a series of experiments. In addition, various sound quality metrics were examined in order to derive design factors affecting sound quality enhancement.

As data emerges as the most valuable resource in the world, the evolution of the related data industry is progressing faster. In this study, we tried to discover effective factors for fuel cell durability by using big data analysis techniques with accumulated vehicle actual road data (de-identified Blue Link Data). Basic analysis is performed assuming factors that are expected to have a significant impact on the fuel cell durability performance, and durability factor modeling according to the clustering between driving patterns and durability performance is used to determine. Now can see the change in durability performance. By analyzing the correlation between each driving pattern and durability performance, it is possible to know the weight of the effective factor affecting the durability. If the effective factor with high weight is improved in the actual vehicle unit, the durability performance is expected to increase, and the effect will be verified through real road operation.

A fuzzy logic ratio control algorithm for a metal belt CVT is suggested considering the on-off characteristics of the ratio control valve and the nonlinear characteristics of the CVT shift dynamics. In the fuzzy logic, variable computation time for the error of the ratio and the rate of the error is suggested depending on the velocity of the rate of the CVT ratio. Experimental results show that a desired speed ratio can be achieved at a steady state by the fuzzy logic in spite of the fluctuating primary pressure. In addition, it was found that a faster response and better robustness can be obtained when compared with those of the PID control. It is expected that the ratio control algorithm suggested in this study can be implemented in a prototype CVT.

Squeak and rattle (S&R) problems in body structure and trim parts have become serious issues for automakers because of their influence on the initial quality perception of consumers. In this study, various CAE and experimental methods developed by Hyundai Motors for squeak and rattle analysis of door systems are reported. Friction-induced vibration and noise generation mechanisms of a door system are studied by an intelligent combination of experimental and numerical methods. It is shown that the effect of degradation of plastics used in door trims can be estimated by a numerical model using the properties obtained experimentally. Effects of changes in material properties such as Young's modulus and loss factor due to the material degradation as well as statistical variations are predicted for several door system configurations. As a new concept, the rattle and squeak index is proposed, which can be used to guide the design.

Owing to the enhanced performance of engines these days, more heat should be dissipated in the braking system. Failure of doing this properly causes temperature rise in the brake disc which result in the brake fade, disc distortion, brake judder, etc. A cooling-air-duct was proposed as a solution to prevent these from happening. In this paper, we present our work based on experiments optimized parameters such as direction, location, shapes and the size of the duct for the cooling-air-duct installation in real cars. We installed the duct extended from a front bumper to a rear wheel guard. Experimental parameters were compared with theoretical analysis using the impinging jet analysis. The heat transfer coefficients were determined by using the finite elements method (FEM). We found that our experimental data is supportive of theoretical analysis. We believe that our results should serve an useful guideline for designing the cooling-air-duct for braking system.