• 접착 및 계면
• /
• 제12권4호
• /
• pp.105-110
• /
• 2011

폴리에스터/멜라민 경화형 도료는 기계적 물성, 내화학성 및 내마모성 등이 우수하여 pre-primed 도료 및 pre-coated metal에 널리 사용되고 있다. 그러나, 폴리에스터 수지 도료의 경화 도막은 강인하지만 유연성과 성형성이 낮은 문제점을 갖고 있다. 본 연구에서는 polycarbonate diol의 long alkyl chain을 폴리에스터 분자 구조 내에 연결시켜 경화 도막의 성형성을 개선하고자 하였으며, 성형성이 개선된 폴리에스터 도료의 선도장 강판용 도료의 적용 가능성을 확인하였다. 또한, 폴리카보네이트디올 분자량이 경화 도막 물성에 미치는 영향을 평가하고자 인장강도와 점탄성을 측정하였으며, 성형성을 확인하고자 drawing test를 실시하였다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 추계학술대회 논문집
• /
• pp.379-381
• /
• 2009

In designing full vehicle, crash safety, fuel efficiency, exhaust gas, and driving stability are very important factors. Especially, automotive wheel which supports total vehicle weight is a critical component in view of driving stability. Most of automotive wheel have been manufactured for beautiful appearance by using aluminum alloy in domestic industry. However, the amount of automotive steel wheel used are on an increasing trend according to developing the advanced high strength steel with good formability property recently. In this study, the circumferential deviation of rim with various thickness and yield strength was investigated. The formability evaluation of the rim was developed by using a finite element module furnished by Forge software.

• 소성∙가공
• /
• 제11권4호
• /
• pp.312-322
• /
• 2002

In this study, an innovative semi-solid die casting technology to replace heavier cast iron compressor parts with lightweight aluminum castings was proposed, and the application possibility for home-appliance component was investigated. The most important factors regarding the semi-solid die casting process are the reheating process of the raw materials to the semi-solid state, specifications of the forming machine, the optimal injection conditions and die design. Materials used in this study were A3S7 and hSn alloys fabricated by the electromagnetic stirring process. The optimal injection conditions for semi-solid die casting process were Presented with the reheating conditions of the semi-solid materials. To investigate the effect of plunger tip shape on the formability and mechanical properties in semi-solid die casting process for complicated shape part, two kinds of plunger tip shape with long and short plunger tip taper are proposed.

• 소성∙가공
• /
• 제9권4호
• /
• pp.379-388
• /
• 2000

This study aims to examine the influence of experimental and numerical factors on the results of the test and finite element simulation to evaluate the formability of sheet metals. The stretch-forming test with a hemispherical punch is carried out to obtain the limiting dome height (LDH) and forming limit diagram (FLD) for several kinds of aluminium and steel sheet. The results of the LDH and FLD tests are analysed to find any correlation with the uniaxial tensile properties. It proves that the size of the prescribed grid has great influence on the measured value of strain. The finite element analysis of the punch stretching process is also carried out and the result is compared with the experimental data. The influence of the numerical parameters such as friction coefficient, element size and anisotropy model on the simulation results tms out to be very considerable.

• Journal of Advanced Marine Engineering and Technology
• /
• 제33권2호
• /
• pp.295-303
• /
• 2009

Forging of square spline was investigated by using finite element methods in this study. Spline is widely used by torque transmitter in the fields of automobile, aircraft, and shipping etc. Friction on the surface of die is regarded as the most important factor to improve the dimensional accuracy for complete forming of spline teeth. Finite element simulation was carried out to improve the formability of the spline, especially remove unnecessary burrs which were extruded in gap between the die and the punch. To remove the burrs, various friction factors are considered on the surfaces of the die in the simulations and punch flat surface was designed. The simulated results were compared with experimental ones. As a results, it is possible to control the growth of burrs and improve formability of spline teeth by applying various friction factors and design of punch flat surface.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 춘계학술대회 논문집
• /
• pp.342-342
• /
• 2005

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 추계학술대회논문집
• /
• pp.229-232
• /
• 2003

In the roll forming process, a sheet or strip of metal is continuously and progressively formed into a desired cross-sectional profile by feeding it through a series of forming roll. Accordingly, it is important to maintain the material properties of the initial sheet and deform uniformly during the roll forming. The roll forming process was estimated in consideration of some factors such as material properties, strip thickness, roll diameter, roll velocity, and the deformation of the material that influence the forming length. The hydroforming technology has been recognized as a new technique in manufacturing industry, especially in automotive industry. The formed pipe in used in hydroforming process is manufactured by the roll forming. The formability during hydroforming is very sensitive to the state of pipes which are made by roll forming. Particularly the amount of hardening during roll forming affects the formability. Therefore, it is necessary to design the optimum roll flower to reduce the local hardening. In this paper, optimum roll flower which has uniform strain distribution through sheet width was obtained by comparing strain distribution in various roll flower. Finite element analysis(FEA) is performed to estimate the strain distribution related to hardening by roll forming. A numerical analysis is carried out by SHAPE-RF.

• 한국콘텐츠학회논문지
• /
• 제21권2호
• /
• pp.520-527
• /
• 2021

본 연구는 전통재래시장의 획일적인 옥외광고물의 소재, 형태, 디자인으로 인한 낮은 실용성에 주목하고 이를 높이기 위하여 옥외광고물의 부착형태에 따른 실용성에 미치는 영향에 관하여 분석하고자 한다. 연구방법은 문헌고찰을 통하여 연구모형과 가설을 설정하고 설문조사를 실시한 후, 요인분석, 계층적 회귀분석 등을 실시한다. 가설1. 전통재래시장 옥외광고물의 평가요소(가독성, 조형성, 상징성)는 실용성에 영향을 미칠 것이다. 가설2. 전통재래시장 옥외광고물의 부착형태(돌출형, 벽면형)는 각각의 평가요소가 실용성에 미치는 영향을 조절할 것이다. 연구결과, 전통재래시장 옥외광고물의 가독성과 조형성은 실용성에 영향을 미치며, 이에 실용성을 높이기 위해서는 돌출형 옥외광고물의 크기, 색채, 폰트, 레이아웃 등이 적당하여 읽기 쉬워야 하며 형태의 균형과 조화가 좋으면 좋을수록 더욱 실용성은 높아질 것이다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2001년도 춘계학술대회 논문집
• /
• pp.44-48
• /
• 2001

Tube hydroforming technology has increased dramatically, mainly by automotive industry in europe and the americas. It is required tube formability, optimized with regard to tribological factors and specially designed die and presses. In this process has many important parameters as expansion ratio of a tube, axial feeding, internal pressure and preforming low pressure. The following paper discusses to combine forming factors and expectation of manufacture problem by hydroforming of automotive radiator support member.

• 소성∙가공
• /
• 제30권2호
• /
• pp.74-82
• /
• 2021

Stretch-flangeability, which is the ability of sheet steels to be deformed into complex shapes, is a critical formability property in automobile body parts. In this study, the center-hole for hole expansion test, which is normally used to evaluate the stretch-flangeability of sheet steels, was prepared by both punching and electrical discharge machining (EDM) methods. Hole expansion ratio (HER) of punched hole was far lower than the HER of EDM drilled hole because of damage/crack in hole-edge due to punching process. The effect of hole-edge condition on HER was quantified by mechanical, fractographic and geometric factors. Based on these factors, the empirical equation used to determine HER for various sheet steels was derived using non-linear regression.