선진국에서 승용차의 에어백 장착이 의무화되기 시작하면서 저렴하고 성능이 우수한 에어백의 국산화 개발이 시급하게 되었다. 에어백 장착시 대당 $300-$1000이 추가로 소요되므로, 전량 수입에 의존하는 대신에 저렴한 국산 에어백의 필요성이 심각하다 하겠다. 지금까지는 국내 자동차 업계에서의 에어백에 대한 관심이 높지 않으나 앞으로는 이에 대한 연구개발이 시급한 실정이다. 본 연구에서는 에어백 개발에 있어서 중요한 기본 기술에 대한 survey가 행하여지며, 앞으로 산업체 등에서 제품 개발시 실질적인 도움을 줄수 있을 것으로 생각한다.

자동차 성능의 고도화 및 사회적 Needs의 변화에 대응하여 철강재료, 특히 특수강 재료의 고급화 및 신강종 개발이 시급히 요구되고 있는 실정이다. 따라서 특히 본 자료에서는 자동차 재료로서의 특수강에 대한 Needs를 파악해 보고 다양해지는 Needs에 대응하여 활발히 진행되고 있는 자동차용 특수강 재료의 개발동향을 주요 구성부품별로 알아보고 아울러 특수강 제조기술의 개발동향을 소개하고자 한다.

내연기관 가솔린엔진에서 점화전은 매우 중요하다. 그것은 2만볼트의 스파크를 흘려 혼합기를 연소시키기 때문이다. 본 고는 통상의 스파크화염보다 수십배 더 큰 화염의 생성을 이루는 몇가지 방법과 그것이 엔진에 미치는 영향들을 분석 제시하여 어느 한 요소가 향상한다고 할 때 혹 타 부문에 여타 영향을 주는지의 여부도 함께 고찰하여 실제로 사용할 수 있는 기술로서의 검토를 함이다.

According as the members and inner and outer plates of the automobile body structure have been thinned their thickness and have become high strength, each part of the body structure has been put more severe stress condition. Therefore, it has been increasingly required to improve the fatigue strength of the spot welded structures. As one of the improving methods for such problem, the author had previously proposed the method of alleviating stress concentration at nugget edge of the spot weld part and improving its fatigue strength [1]. But, because fatigue strength of the spot welded lap joint is influenced by its geometrical and mechanical factors, welding condition and etc., there needs a quantitative and systematic estimation method of them. In this report, by considering nugget edge of the spot weld part of the spot welded lap joint subjected to tensile load to the ligament crack, fatigue strength of various spot welded lap joints was estimated with the stress intensity factor (S.I.F.) K which is fracture mechanical parameter. It is known that evaluation of fatigue strength of the spot welded lap joint by the stress intensity factor (S.I.F.) K is more effective than the maximum stress $(\sigma_{ymax}$) at edge of the spot weld part on the center line of width of the plate.

In this paper, an attempt is made to analyze the impulsive stress directly underneath the concentrated impact point for a supported square plate by using the three-dimensional dynamic theory of elasticity and the potential theory of displacement (stress function) on the supposition that the load, F$_{*}$0 sin .omega.t, acted on the central part of it. The results obtained from this study are as follows: 1. The impulsive stress cannot be analyzed directly underneath the acting point of concenrated impact load in privious theories, but can be analyzed by using the three-dimensional dynamic theory of elasticity and the potential theory of displacement. 2. Theorically, with increasing the pulse width of applied load, it was possible to clarify that the amount of stress in the point of concentrated impact load was increased and that of stress per unit impulse was decreased. 3. The numerical inversion of laplace transformation by the use of the F.F.T algorithm contributes the reduction of C.P.U time and the improvement of the accuracy or results. 4. In this paper recommended, it is found that the approximate equation of impact load function P (.tau.) = A.tau. exp (-B.tau.), and P (.tau.) =0.85A exp (-B.tau.) sinC.tau. could actually apply to all impact problem. In compared with the experimental results, the propriety of the analytical method is reasonable.

This paper presents the results of static crushing test that was conducted to characterize the energy absorption and collapse characteristics of composite box tubes. Fifteen specimens were fabricated with woven fabric prepreg using [0/90] glass/epoxy and were autoclave cured. Quasistatic compression test was performed on them. Collapse mode and energy absorption capacity vary significantly as a function of the thickness and length of a square side of composite box tube.

Air/fuel ratio control system for gasoline engines has been analyzed to determine the control gain of the system. In this analysis the engine is modelled to be a simple time delaying element and the ramp-and-jump method is used to control air/fuel ratio. The result shows that it is necessary to measure the air flow rate accurately to enhance the control performance. And also it is shown that the control gain must be determined in some bounded region to meet the fast dynamic response and high catalyst conversion efficiency together.

Combustion characteristic, concentration of NOx and exhaust smoke opacity was experimentally tested, according to fuel injection timing, mixing ratio of water and methanol for the driving condition of 2000 rpm of engine revolution and constant load(7.5kg/cm$^{2}$) using emulsified fuel of gas oil-water methanol. The result obtained was as following. Thermal efficiency indicated highly 0.4-2.7% for emulsified fuel then gas oil, and injection timing when maximum thermal efficiency, slicily risen then gas oil. For constant fuel injection timing ignition lag was increased, combustion duration decreased, maximum heat release rate indicated high, and concentration of NOx and exhaust smoke opacity is decreased, as function of water and methanol content y was higher.

In the quantitative analysis of oxygenated exhaust emissions (unburned methanol, formal- dehyde) from methanol fueled vehicles, the oxygen contained in oxygenated exhaust gases lowers the FID (Flame Ionization Detector) response factor of conventional THC analyzer and leads to erroneous HC reading. For correct measurement of various HCs including oxygenated HCs emitted from FFV(Flexible Fuel Vehicle), first of all, the measurement technique of real HC emissions should be established. GC and HPLC-DNPH measuring methods specified by the EPA are used in this paper to analyze unburned methanol and formaldehyde components in the exhaust emissions. In emission test of FFV, unburned methanol and formaldehyde are emitted mostly during cold transient period, and it is shown that formaldehyde emission level is proportional to engine displacements. In view of the HC emission level, vehicle using M85 has 40% advantage over gasoline-fueled vehicle in OMHCE and has a good potential of a low emission vehicle.