• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.195-200
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• 2001

Composites have wide applications in aerospace vehicles and automobiles because of the inherent flexibility in their design for improved material properties. Composite tribes in particular, are potential candidates for their use as energy absorbing elements in crashworthiness applications due to their high specific energy absorbing capacity and the stroke efficiency. Their failure mechanism however is highly complicated and rather difficult to analyze. This includes fracture in fibres, in the matrix and in the fibre-matrix interface in tension, compression and shear. The purpose of this study is to investigate the energy absorption characteristics of CFRP(Carbon Fiber Reinforced Plastics) tubes on static and impact tests. Static compression tests have been carried out using the static testing machine and impact tests have been carried out using the vertical crushing testing machine. Interlaminar number affect the energy absorption capability of CFRP tubes. Also, theoretical and experimental have the same value.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1331-1332
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• 2010

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2945-2951
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• 2000

Because of the inherent flexibility in their design for improved material properties, composites have wide applications in aerospace vehicles and automobiles. The purpose of this study is to investigate the energy absorption characteristics of CFRP( Carbon Fiber Reinforced Plastics); tubes on static and impact tests. Static compression tests have been carried out using the static testing machine(Shin-gang buckling testing machine)and impact compression tests have been carried out using the vertival crushing testing machine. When such tubes were subjected to crushing loads, the response is complex and depends on the interaction between the different mechanisms that control the crushing process. The collapse characteristics and energy absorption were examined. Trigger and interlaminar number affect energy absorption capability of CFRP tubes.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.167-170
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• 2004

In order to investigate the impact behaviors of 3-D braided glass/epoxy composites, the energy profiles and damage area were compared to the laminates of similar volume fraction and composition. The energy profiles showed different characteristics from each other which indicates they have distict energy absorption mechanisms. The image analysis on the damage projections visualized the crack propagation paths along the fiber direction.

• Structural Engineering and Mechanics
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• v.54 no.6
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• pp.1245-1266
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• 2015

In this research, the cylindrical absorber made of expanded metal sheets under impact loading has been examined. Expanded metal sheets due to their low weight, effective collapse mechanism has a high energy absorption capacity. Two types of absorbers with different cells angle were examined. First, the absorber with cell angle ${\alpha}=0$ and then the absorber with angle cell ${\alpha}=90$. Experimental Study is done by drop Hammer device and numerical investigation is done by finite element of ABAQUS software. The output of device is acceleration-time Diagram which is shown by Accelerometer that is located on the picky mass. Also the output of ABAQUS software is shown by force-displacement diagram. In this research, the numerical and experimental study of the collapse type, force-displacement diagrams and effective parameters has been investigated. Similarly, the comparison between numerical and experimental results has been observed that these results are matched well with each other. From the obtained results it was observed that the absorber with cell angle ${\alpha}=0$, have symmetric collapse and had high energy absorption capacity but the absorber with cell angle ${\alpha}=90$, had global buckling and the energy absorption value was not suitable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1341-1344
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• 2003

Studies on impact damage of composite laminate shells were fewer compared with those on impact behaviors to analyze time-load, displacement-load and impact energy - energy absorption. Up to date the studies were not enough to demonstrate suitability of their results because they were dependent on theories and numerical analyses. In particular, it is a well-known fact that there was a correlation between initial peak load and damage resistance of composite material flat plates imposed with low-speed impact, but studies on composite material shells with curvature were also very few. Actually structures such as wings or moving bodies of airplanes, motor cases and pressure containers of rockets are circular. And as low-speed impact load is imposed for optimal design of take-off and landing, and containers of airplanes, it is very important to analyze evaluation of behaviors and damaged areas. Therefore, in this paper to evaluate the impact characteristics of the CFRP laminate shell according to size of curvature quantitatively, it was to identify energy absorption and impact damage instruments according to change of impact speed.

• Journal of the Korea Safety Management & Science
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• v.3 no.1
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• pp.127-137
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• 2001

Because of the inherent flexibility in their design for improved material properties, composites have wide applications in aerospace vehicles and automobiles. The purpose of this study is to investigate the energy absorption characteristics of CFRf (Carbon Fiber Reinforced Plastics) tubes on static and impact tests. Static compression tests have been carried out using the static testing machine(Shin-gang buckling testing machine) and impact compression tests have been carried out using the vertical crushing testing machine. When such tubes were subjected to crushing loads, the response is complex and depends on the interaction between the different mechanisms that control the crushing process. The collapse characteristics and energy absorption were examined. Trigger and interlaminar number affect the energy absorption capability of CFRP tubes.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.155-162
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• 1999

Extruded aluminum sections are used to the light construction of the rall vehicles structures However, the research works on the crashworthy design of the extruded aluminum sections are not published sufficiently in this paper, the impact energy absorption characteristics of extruded aluminum sections are investigated by crash simulation and test The optimized energy absorbing studies are also performed based on the selected design parameter variations of the sectional shapes and the dimensional ratios.

• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.713-727
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• 2018

Thin-walled mental tubes under lateral crushing are desirable and reliable energy absorbers against impact or blast loads. However, the early formations of plastic hinges in the thin cylindrical wall limit the energy absorption performance. This study investigates the energy absorption performance of a simple, light and efficient energy absorber called the ring stiffened tube. Due to the increase of section modulus of tube wall and the restraining effect of the T-stiffener flange, key energy absorption parameters (peak crushing force, energy absorption and specific energy absorption) have been significantly improved against the empty tube. Its potential application in the offshore blast wall design has also been investigated. It is proposed to replace the blast wall endplates at the supports with the energy absorption devices that are made up of the ring stiffened tubes and springs. An analytical model based on beam vibration theory and virtual work theory, in which the boundary conditions at each support are simplified as a translational spring and a rotational spring, has been developed to evaluate the blast mitigation effect of the proposed design scheme. Finite element method has been applied to validate the analytical model. Comparisons of key design criterions such as panel deflection and energy absorption against the traditional design demonstrate the effectiveness of the proposed design in blast alleviation.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.17-22
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• 2011

Ultimate goals in vehicle design can be summarized as environment-friendliness and safety. Along with these requirements, the importance of natural environment conservation has been focused lately. Therefore, reduced emission from vehicle and improved efficiency has become the top priority projects throughout the world. CFRP(Carbon Fiber Reinforced Plastics) of the advanced composite materials as structure materials for vehicles, has a widely application in lightweight structural materials of air planes, ships and automobiles because of high strength and stiffness. This study is to investigate the energy absorption characteristics of CFRP hat-shaped section members under the axial impact collapse test. The CFRP hat-shaped section members which manufactured from unidirectional prepreg sheets were made of 8plies. The axial impact collapse tests were carried out for each section members. The collapse mode and energy absorption characteristics were analyzed for CFRP hat-shaped section member according to the interface numbers(2, 3, 4, 6 and 7).