• Transactions of Materials Processing
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• v.26 no.1
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• pp.55-62
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• 2017

This paper proposes the process to develop a light-weighting automotive door assembly using high strength steel with low cost penalty. In recent years, the automotive industry is making an effort to reduce the vehicle weight. In this study, inner panels for automotive front door using thinner sheets and quenchable boron steel were designed to reduce the weight of conventional one. In order to evaluate the stiffness properties for the proposed door design, the several static tests were conducted using the finite element method. Based on the simulation results, geometry modifications of the inner panels were taken into account in terms of thickness changes and cost saving. Furthermore, a prototype based on the proposed design has been made, and then static stiffness test carried out. From the results, the proposed door is proved compatible and weight reduction of 11.8% was achieved. It could be a reference process for automotive industry to develop the similar products.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.147-148
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• 2023

Steel doors, which are common in general buildings, do not seal the gap between the door and the floor, so drafts, noise, dust, and lights flow from the outside, and shielding devices are installed in various materials and methods, such as adding magnetic gate paper to the side of the door or installing a gasket under the door, but performance is limited. Accordingly, in order to fundamentally solve these problems, we researched and developed a double gap blocking device that can improve fire resistance and airtightness performance in steel doors. Unlike general products, the double gap blocking device has the advantage of maximizing airtight performance by forming an air layer in the center when the door is closed, as well as greatly improving the fire resistance performance, which is the basic performance of the fire door.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.133-134
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• 2023

In general, all buildings are equipped with various types of handles for opening and closing the door, and unlike wooden doors, steel doors such as fire doors are equipped with a box-shaped door lock box frame surrounding the outside of the door lock to protect the door lock, which is called a cylinder protection cover. These cylinder protection covers have various types and types of fastening structures, and the cylinder protection covers on the market are molded in factories and standardized according to the size and shape of the door lock, requiring various types of cylinder protection covers. Accordingly, a variable cylinder protection cover with a simple prefabricated structure that can fundamentally solve these problems can be used as one cylinder protection cover regardless of the type, shape, and size of the door lock.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.7-12
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• 2008

A hot stamping technology of vehicle door impact beam made of thin sheet steel has been developed, with the aim of ensuring occupant safety in a side collision. This technology has been implemented to increase the strength of vehicle body parts and to reduce not only the weight of door impact beam but also the number of work processes. Mechanical tests were performed to obtain material properties of hot-stamped specimen and those were used as input data in stamping and structural simulation for optimal design of door impact beam. Strength of hot-stamped door impact beam increased to the value 102% higher than that of conventional pipe-shaped door impact beam and structural simulation showed that hot-stamped door impact beam achieved 28% weight reduction.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.379-385
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• 2016

Door impact beam plays a key role in minimizing the occupant injury within the side impacted vehicle through preventing intrusion of the impacting vehicle. Steel pipe type door impact beam has been widely adopted since it has simple structure and the overall strength is easily determined according to the pipe size. The brackets welded at pipe ends connect the door impact beam and the door panels by spot welds. In this study, first, the effect of pipe thickness, bracket thickness and door mounting stiffness was respectively analyzed. Next, application of the tailor rolled pipe was examined and several alterations of the bracket mounting method were considered. Application of tailor rolled pipes with superior bracket mounting method showed remarkable strength enhancement and weight reduction possibility in comparison with the current door impact beam.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.125-132
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• 2002

Recently, ULSAB(Ultra Light Steel Auto Body) concept is getting more attention due to various benefits in automotive body design. One of the ULSAB efforts is making a door with TWB(Tailor Welded Blanks). In TWB, two or more patches of steel panels are welded together before stamping process. In this research, domains and thicknesses of the patches in a front door structure are determined by a series of optimization schemes composed of topology, size and shape optimization and DOE(Design of Experiments) scheme. A door is designed to have better performances compared to exiting structure considering static stiffness and natural frequency. The final design is discussed and compared to the existing design.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.918-923
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• 2007

Currently, automotive industries improve the vehicle performance and reduce the development period of vehicle using each module part for the high quality and performance of vehicles. However each component part doesn't generate the noise and vibration problems, sometime these problems are generated on the assembly status between vehicle chassis frame and each module part. On this study, in order to analysis the dynamic characteristics of a shield door module that is a typical module part of vehicles, the acquisition and evaluation process about the vibration and noise of shield door module is developed. Also the possibility to apply to shield door module of the developed process is verified by the comparison with the dynamic characteristics between plastic and steel module plate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1516-1523
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• 2015

This study investigates the stress concentration factor of a door opening of an offshore tubular steel tower. The tubular steel tower is subjected to eight (8) different load combinations which are deemed to be normal and abnormal operating cases for the ultimate limit state and serviceability limit state. Analytical method using parametric equations and numerical method of finite element are used to analyze the stress components as well as any translations or rotations where the flow of stress is interfered with. A finite element program, ABAQUS, is used for the numerical method analysis. Trends of the stress concentration in the localized area near the opening are studied, and points of interest are defined for comparison among three different cases of tubular steel tower: without door and without reinforcement; without door opening and with reinforcement; and with door opening and with reinforcement. Findings are tabulated and shown in illustrative charts, and conclusions are made.

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.29-35
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• 2013

The research is to verify by experiments whether the steel truss structure is able to withstand the load of cement bricks of upper part of a door for the safe use of lightweight steel truss structure instead of concrete lintel which is to be installed at upper part of door frame in building cement bricks for apartment construction. The steel truss is designed in order not to disturb bricks-building and the shape of structure was verified by bending test. According to experiments result, camber was applied to steel structure that enabled construction work to be improved and was proved effective for the prevention of accidents by cement bricks-building load test.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.103-110
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• 2021

The mounting performance of the GFRP(Glass fiber Reinforced Plastic) beam and the mechanical mounting of the steel bracket was studied to be mounted as a GFRP impact beam on the side door of the passenger car. Moreover, an open-hole tensile test was performed to evaluate breakage tendency based on GFRP stacking conditions. Furthermore, the tightening strength of rivets and bolts was compared using the single lap-shear tension test for the GFRP stacking pattern. Additionally, the GFRP beam and bracket mounting features were designed; moreover, the prototype and bracket were assembled. Additionally, the bracket mounting bending test and the door assembly static bending test were performed to verify the stability of the bracket mounting. In the bracket fastening bending test, no breakage occurred in the connection part between the GFRP beam and the bracket, and it showed 67% (24.4 kN) improved performance compared to steel. In the static bending test of the door assembly, the initial average reaction force increased by 25% compared to the steel, and the performance of all FMVSS-214 regulations was satisfied. The replacement of GFRP impact beams resulted in a 30% weight reduction