• 동력기계공학회지
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• 제14권1호
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• pp.11-15
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• 2010

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions from the diesel engines are recognized as main cause which has a great influence on environment. In this study, the potential of biodiesel fuel and oxygenated fuel(ethylene glycol mono-n-butyl ether; EGBE) was investigated as an effective method of decreasing the smoke emission. The smoke emission of blending fuel(EGBE 0~20 vol-%) was reduced in comparison with diesel fuel and it was reduced approximately 64% at 2000 rpm, full load in the 20% of blending rate. On the contrary NOx emissions from biodiesel fuel and EGBE blended fuel were increased compared with diesel fuel. Torque and brake specific energy consumption(BSEC) didn't have large differences.

• 소성∙가공
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• 제18권5호
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• pp.416-421
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• 2009

The applications of the aluminum alloy sheets to the auto-body panels are dramatically increasing for weight reduction of the automobiles. However, low formability of the aluminum alloy sheet compared to the steel sheet can be obstacles in tool manufacturing processes. Therefore, many of yield criteria for the anisotropic materials such as the aluminum alloy sheet have been observed. In this study, the biaxial tensile test and FLD test for the aluminum alloy sheet are performed. The results are compared with Hill's 1948 and Hill's 1990 models by means of theoretical predictions. Finite element analysis was also performed using the proposed method for the real panel.

• 소성∙가공
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• 제20권8호
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• pp.575-580
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• 2011

Direct laser melting(DLM) is promising as a joining method for producing parts for automobiles, aerospace, marine and medical applications. An advantageous characteristic of DLM is that it affects the parent metal very little. The mechanical properties of parts made by DLM are strongly affected by the porosity and surface roughness of the laser melted beads. This is a systematic study of the effects of the porosity and surface roughness of laser melted beads using various processing parameters, such as laser power, scan rate and overlapping ratio of the fill spacing. The specimens were fabricated with 316L and 304L austenitic stainless steel powder. Dense parts with low porosity were obtained at low laser scan speed, as it increased the aspect ratio of the parental material and the depth of penetration. The variations of surface roughness were examined at various processing parameters such as overlapping ratio and laser power.

• 소성∙가공
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• 제17권4호
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• pp.292-301
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• 2008

Type 2 compressed natural gas(CNG) storage vessels for automobiles are becoming widely used. They are not only supplied to automakers in Korea, such as Hyundai Motors, but increasingly, they are being exported overseas. Autofrettage is a process that produces beneficial residual stresses in a vessel by subjecting it to excessive internal pressure. This strengthens the vessel and improves its fatigue resistance. This paper presents research investigating the autoftettage process and residual stresses it produces in type 2 CNG storage vessels. A finite element analysis technique and a closed form equation are used. Then, fatigue resistance is analyzed through a fatigue evaluation performed according to ASME section VIII.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.347-350
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• 2011

Automobiles should be light and practical to reduce the price of manufacturing and maintaining expense. Hatchback vehicles are far from the silence for its practicality. This paper introduced the effective method of the planning of the asphalt material which applies the asphalt damping material. This paper showed the experiment which restrains the vibration of the vehicle trunk using asphalt damping material and chose the position of damping material using the velocity map and strain energy map and planed the optimum position.

• Journal of Chest Surgery
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• 제22권6호
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• pp.1070-1077
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• 1989

Traumatic injuries of the diaphragm are not an infrequent occurrence with rise in violence and increasing use of automobiles, more diaphragmatic injuries may be seen. Fifty cases from Severance hospital were reviewed of these there were 27 injuries secondary to blunt trauma and 23 penetrating injuries, and occurred commonly in male. In blunt trauma, right and left diaphragmatic injuries occurred equally. Chest X * ray were normal in 18 cases [36 %], a hemo-and/or pneumothorax was present in 22 cases [44 %], and only 12 cases[24 %] were diagnosed or suspected as diaphragmatic injuries preoperatively. Seventeen cases underwent thoracotomy alone, 19 cases required laparotomy only, and 14 had combined thoracotomy and laparotomy. There were 5 deaths [10 % mortality], and all deaths related to the severity of associated injuries. It was concluded that injuries of the diaphragm should be suspected in all patients with severe blunt torso trauma or penetrating injuries near the diaphragm.

• 한국생산제조학회지
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• 제20권2호
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• pp.202-206
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• 2011

Works on the strength and stiffness in the structural members are carried out widely with various material and cross-sections with ever increasing safety concerns, they are presently applied in various fields including railroad trains, air crafts and automobiles. In addition to this, problem of lighting structural members became important subject by control of exhaust gas emission, fuel economy and energy efficiency. So, Light weight of member structures is necessary for the high performance and various functions. In this study, the CFRP flat and circular member was manufactured by CFRP prepreg sheet in autoclave. Carbon FRP is an anisotropy material whose mechanical properties change with its fiber orientation angle, so this study apply to the effects of the fiber orientation angle on the bending characteristics of the member. Each CFRP flat and circle are compared by strength and stiffness.

• 대한기계학회논문집A
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• 제32권11호
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• pp.1035-1040
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• 2008

Replacement period for vehicle cabin filter of most automobiles is fixed without consideration of conditions of filter and environment. Auto alarm system of replacement period at vehicle cabin filter and interception system of high concentration dust were developed. Control program which is related with the AQS has been developed based on the circuit drive algorithm. This system is expected to be beneficial to passenger's health and to extend the life of the filter which regulates vehicle HVAC system by ventilation mode change at the time of high concentration dust.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.855-861
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• 2002

This paper demonstrates the reconstruction of input signals from only the measured signal for the simulation and endurance test of automobiles. The aim of this research is concerned with input signal reconstruction using various iterative teaming algorithm under the condition of system characteristics. From a linear to nonlinear systems which provides the output signals are estimated in this algorithm which is based on the frequency domain. Our concerns are that the algorithm can assure an acceptable stability and convergence compared to the ordinary iterative learning algorithm. As a practical application, a f car model with nonlinear damper system is used to verify the restoration of input signal especially with a modified iterative loaming algorithm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.399-404
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• 2002

Analyzing acoustic-structural systems such as automobiles and aircraft the FRF-based substructuring method is one of the most powerful tools. In this paper, an optimization procedure far the engine mount system of passenger car has been presented using the design sensitivity analysis based on the multi-domain FRF-based substructuring formulation. The proposed method is applied to an optimization problem of the engine mount system, of which objective is to minimize the interior sound over the concerned rpm range. The design variables selected are the stiffnesses of the engine mounts and bushes. Plugging the gradient information calculated by the proposed method into nonlinear optimization software, we can obtain the optimal stiffnesses of the engine mounts and bushings through design iterations. The optimized interior noise in the passenger car shows that the proposed method is very useful in the realistic situation.