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In this paper, an improved grey Euclidean relational analysis method based on Euclidean distance was proposed, which was based on the traditional grey relational analysis method. This method was applied to the material-structure integrated design of the backrest skeleton of a car seat. Firstly, the steel backrest skeleton of a car seat was replaced by carbon fiber reinforced plastics (CFRP), and the backrest skeleton was designed as an integrated structure. Its weight was reduced by 1.69 kg (39.12 %) while still meeting various seat performance test requirements. Then, the effect of the ply design on the performance of car seats with CFRP was studied, and the optimal layer scheme of CFRP backrest skeleton of car seats was obtained by combining the grey Euclidean relational analysis method. Finally, the method proposed in this paper was compared with the widely used method. The results showed that the optimization schemes obtained by the two methods greatly improved performance indicators, especially L_R_2 which had an improvement rate of 13.31 %. Additionally, the proposed method reduced computing resources by 95 %, indicating its ability to effectively balance optimization results and calculation efficiency. [ABSTRACT FROM AUTHOR]

Work presented in this article concerns an industrial example of a mass optimization problem, performed on automotive suspension components. Due to the fact, that the considered element, i.e. spring seat is a part of the vehicle suspension module, analyses are performed on the shock absorber assembly level with the mutual interaction of each body. To solve constrained optimization task, a combination of genetic and gradient-based algorithms are used, involving nonlinear static strength problem, represented by finite element method analysis. Parametric representation of considered component geometry is used, incorporating manufacturing restrictions and design assembly requirements. The final, optimized form of the spring seat is then compared with its initial shape, i.e. "working space", especially under constraints fulfillment, which are specified by the customer. Performance comparison of used methods (or combination of such) is the aim of this paper, focusing on practical aspects of work, i.e. final mass decrease, number of function calls, or design space exploration capabilities. The optimization method presented hereby is universal and can be adapted to many fields of industry, wherever efficient mass reduction must be achieved incorporating the feasibility of the component. The hybrid optimization approach presented in the paper allows effective mass reduction and works well for multimodal objective functions typically found in industrial applications. [ABSTRACT FROM AUTHOR]

The main goal of this paper is to analyze flow loss of the ventilated seats by seating position for driver. Also, this work includes the method of analysis as to body pressure distribution, ventilation performance, subjective valuation, and flow loss. The experiment is conducted with a male who is 75 kg of weight and 177 cm of height corresponding AM 50 % (American model) and the evaluation of the vehicle seat is conducted through the regular inspections after mass production system. As far as the seating positions as experimenter preference is concerned, it is verified to stress the load at cushion and back from the body pressure. The trend of ventilation performance is shown to be highly at internal temperature sensors attached to face of the vehicle seat without working ventilation. Consequently, the temperature range of cushion and back of vehicle seat is increased in order of lay down < lean(rest) < normal conditions. [ABSTRACT FROM AUTHOR]

With the reduction of vehicle interior noise, the Buzz, Squeak and Rattle (BSR) noises have become an intractable problem that needs to be tackled urgently. Seat system rattle noises have a large contribution to the passengers' complaints, due to the close distance between the passengers and seats. The seat structure and its components can be sources of rattle noise based on their physical characteristics. The aim of the present paper is to characterize the sound quality property of rattle noise in seat system, and subsequently, use the characteristics of the rattle noises to assess the subjective responses to the noise. In this study, sound metrics are computed for the signals recorded at different points in the seat system. To be more specific, the signals are recorded before and after the durability test in different loading states. Consequently, the characteristics of the rattle noises were compared and analyzed, and the jury test was performed. On this basis, a rattle index and evaluation models were developed. It is expected that the developed rattle evaluation system and sound quality index can be used to reduce the automotive interior rattle noise in terms of subjective levels as well as objective levels. [ABSTRACT FROM AUTHOR]

Instead of a monolayer, multi-layered cushion can be promising to develop more comfortable automotive seat if the layer materials are properly selected. In this study, we have examined the seating comfort of different types of multilayer seat cushions. Polyurethane foams (PUFs) of three different hardness, memory foam, and technogel were used in different combination to prepare four types of multilayer seat cushions. The short-term seating comfort of the seat cushions has been investigated in terms of hardness, initial hardness factor (IHF), modulus irregularity factor (MIF), sag factor (SF), and hysteresis loss as derived from the indentation force deflection (IFD) curves. Long-term comfort has been compared to the respective stress relaxation behavior of the seat cushions. It has been observed that both the short and long-term conditions of comfort are not only influenced by the characteristics of the upper layer, but also by the bottom layer (i.e., supporting material). The present work will help the seat designer to consider the material characteristics for fabricating a good automotive seat on the basis of the desired features needed to provide traveling passengers with proper short- and long-term comfort. [ABSTRACT FROM AUTHOR]