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The Automotive Interior Parts offer convenience and riding comfort for passengers. One of its main features is that it is placed in a conspicuous place. Therefore, automotive interior part manufacturer attach importance to appearance quality. Additionally, appearance quality of Interior Parts is more important as the senses of passenger heighten. Most Automotive Interior Parts manufactured by Injection Molding to mass produce it with complex geometry. But there are numerous defects in method of Injection Molding. Especially, large products like automotive interior parts are disadvantage. A typical example of defects is weld line, sink mark, short shot. These are having an adverse effect on the appearance quality as well as another quality like BSR (Buzz Squeak Rattle) and Side impact performance. In order to improve problem, molding has been modified and spray coating has been done over the past.

Carmakers have tried to lower the vehicle weight for raising fuel efficiency. This trend involves a trade-off with the vehicle stiffness. In automobile interior parts, the thickness has needed to be decreased for the weight reduction but this makes the stiffness worse. A new approach for improving the stiffness due to the weight reduction is required and various optimization methods at early development stage have been introduced currently. However, it is difficult to apply optimization for the interior parts since many interior parts' structures generally depend on the design. But as studying the structure in detail, we discovered some factors that affect the performance without depending on design. The door trim is selected for optimization item because it has many characteristics of automobile interior parts. In our case study, the factors that improve the performance of door trim without changing design are considered as fastener position and flange rib layout.

The sound inside a passenger cabin is composed of many elements, which include irritating noises such as buzzes, squeaks and rattles. Customer perception of buzz, squeak and rattle (BSR) is measured by Things Gone Wrong (TGW), warranty claims and JD Power surveys.1) The Speaker BSR test has been adopted to evaluate and to eliminate rattle noise of a door module while playing sound through the audio system. Subjective listening had been the preferred method for rattle noise detection, due to the sound of the audio system in any measurement. In this paper a quantitative approach for the rattle noise under the speaker test is proposed. The HANIL E-HWA rattle index was developed using a high pass filter, hiss noise reduction filter, SPL data with short time constant, peak value and fluctuation. The high pass filter was adopted to separate the rattle noise from the speaker sound, due to much higher sound pressure level [108 dB(A)] in the latter case.

Recently, major car maker is specified squeak and rattle test method for subsystems or components by objective method. Generally these test method is focused on vibration environmental conditions. Especially, door trim which is located close to occupant is required additional test for squeak and rattle which is produced by occupant's interaction with door trim. To evaluate this condition, generally it can be tested by subjective method such as striking or pushing and twisting several positions of door trim. Dosing so is very time consuming and including variation results as different decisions. So, this paper suggest a new approach for evaluating squeak and rattle which is relating occupant contacting conditions to interior part, especially interior door trim. Multi-axis robot arm is examined to push automatically several points of door trim.

The complete evaluation of the side vehicle structure and occupant protection is only possible by the full-scale side impact crash test. But auto part manufactures, such as door trim makers can't conduct the test especially when the vehicle is under developing process. And important information and components for estimating crash performance is restricted. With the proposed design procedure for the door trim by a simple impact test method was demonstrated to evaluate the abdominal injury. In addition to simple test, Euro-NCAP test result that is conducted by referenced full-scale test in Korea is compared with several test results. In conclusion, this simple test method have similar trend for abdominal injury index so that it is possible to present guidelines of door armrest design to carmaker at the early stages of vehicle program development.