• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.10a
• /
• pp.318-318
• /
• 2009

The door stiffness is one of the important factors side impact. Generally, the researches have been conducted on the assembled door module. This study is to analysis the side impact characteristics for automotives door module. The impact characteristics have been determined by door module side impact test machine. To determine the initial, intermediate and peak crush resistances use the plot of load versus displacement and obtain the integral of the applied load with respect to the crush distances specified below for each door tested. The initial crush resistance is the average force required to deform the door through the initial 6 inches of crush. The intermediate crush resistance is the average force required to deform the door through the initial 12 inches of crush. The peak crush resistance will be directly obtained from the plot of load versus displacement since it is the largest force required to deform the door through the entire 18 inches crush distance. The data are used to determine if a specific vehicle or item of automotives equipment meets the minimum performance requirements of the subject Federal Motor Vehicle Safety Standard(FMVSS). FMVSS Static 214, Side impact protection, specifies performance requirements for protection of occupants in side impact crashes.

• Journal of Aerospace System Engineering
• /
• v.4 no.3
• /
• pp.1-5
• /
• 2010

Understanding the crushing behaviour of aluminum honeycombs under dynamic loading is useful for crash simulations of vehicles and for design of impacting energy absorbers. In the study of honeycomb crushing under quasi-static, dynamic loading, the most important parameter is crush strength. Crush strength is indicated to energy absorption characteristic of aluminum honeycomb. In this study, Using Finite Element Analysis carried out crush strength of hexagonal aluminum honeycomb then the results was compared with Quasi-static test. Consequently, Crush strength is different in quasi-static loading and dynamic loading about 16%.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2000.04a
• /
• pp.181-188
• /
• 2000

This paper describes the energy absorption of a square tube under axi compression by using the finite element method. The overall deformations and lo buckling modes of tube was discussed by "plastic hinge concep Force-displacement function was plotted to show various state that depended or time. Also, mean crush load was expressed as a type of section geometry a material property using dimensional analysis. To verify the energy absorption and the effects of dimensions, The standards Wt used as related density and specific energy, mean crushing load and the resL were discussed by the relation between crush load and deformation, the relati between related density and specific energy, the relation between crush load a mean crush load, the relation between mean crush load and specific energy.ergy.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.738-743
• /
• 2004

In this paper, the crush characteristic of the tilting train express M-car was estimated under a head-on collision scenario. The car body was divided into three parts - front, middle, and rear. For each part, crush-force relation was evaluated numerically using LS-DYNA 3-diementional shell element analysis. This result will be used for one-dimensional collision analysis of the full train rake.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.616-621
• /
• 2004

In this paper, the crush characteristics of a tilting train express (TTX) M-car design are evaluated with a head-on collision scenario. Its body shell is divided into three parts - front end, middle section, and rear end. For each part, crush-force relation is evaluated numerically through 3-dimensional shell element analysis with LS-DYNA. TTX's embody structure is a hybrid type structure made of steel and composite materials. Composite sandwich panels are modeled as layered shells whose layers have different material properties. And a damage material model is used to consider the effect of stiffness degradation during deformation. The crush characteristics obtained from these calculations will be used as material modeling data of full-rake collision analyses.

• Polymer(Korea)
• /
• v.24 no.6
• /
• pp.829-836
• /
• 2000

In order to recyle the FRP waste from SMC bathtubs and rock-crush sludge obtained as a byproduct of stones, the composite consisting of the FRP and rock-crush sludge and the unsaturated polyester matrix resin were prepared. To enhance the interfacial bonding force between the reinforcements and the matrix resin, the rock-crush sludge was treated with silane coupling agent, ${\gamma}$-methacryloxypropyltrimethoxysilane (${\gamma}$-MPS) and their mechanical properties and interface phenomena were examined. The flexural modulus of the composite containing 10 wt% rock-crush powder treated with 3 wt% silane coupling agent showed the maximum value. And also the initial thermal degradation temperature of composites were in the range of 352~359$^{\circ}C$. From these results, we observed that the weight loss of composites was almost constant regardless of the concentration of silane coupling agent. It is confirmed that the interface of the composites containing filler treated with ${\gamma}$-MPS was improved in that there were no pull-out phenomena between the reinforcement and matrix resin.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.18 no.4
• /
• pp.348-354
• /
• 2009

In order to reduce the risk of roll over crash, one of the greatest risk events, National Highway Traffic Safety Administration(NHTSA) issued Notice of Proposed Rulemaking(NPRM) enhancing the safety standard on roof crush resistance, FMVSS No. 216 and changing some part of the test procedure. According to this NPRM, the boundary Gross Vehicle Weight Rating(GVWR) of the vehicles applied by this standard is extended from 2,722kg(6000 lb) to 4,536 kg(10000 lb) and the applied test force is increased from 1.5 times to 2.5 times of Unloaded Vehicle Weight (UVW). Also the current limit on the amount of roof crush, 127mm(5 inch), is replaced with a new requirement of maintaining enough headroom without touching the head of a seated 50% male dummy. In this paper, we carried out the rollover crash test on some domestic cars and investigated their safety due to the KMVSS No. 92 and the enhanced safety standard, FMVSS No. 216, respectively. The result shows that most of them can satisfy the new standards but further tests will be necessary, especially for heavier cars.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.12
• /
• pp.2703-2714
• /
• 2002

In this work, energy absorption characteristics and optimal welding space of spot-welded square hat type tube are investigated via quasi-static crush experiments and finite element (FE) analyses. A FE model reflecting the crush characteristics is established based on the experimentally observed crush mechanisms of specimens with welding spaces (20, 30 & 45 mm) and (25,40 & 55 mm) respectively for two specimen widths (60, 75 mm). The established FE model is then applied to other crush models of widths (50, 60 & 75 mm) with various welding spaces (20, 25, 30, 40, 45, 55, 75, 150, 300 mm) respectively. We examine the energy absorption characteristics with respect to the welding space for each specimen width. The outcome suggests an optimal spot welding space of square hat type thin-walled tube. Energy absorption is also presented in terms of yield strength of base metal, specimen thickness, width, and mean crushing force of spot-welded square hat type thin-walled tube.

• Composites Research
• /
• v.22 no.4
• /
• pp.1-12
• /
• 2009

In this paper, quasi-static crushing tests of composite circular tubes under axial compression load are conducted to investigate the energy absorption characteristics. Circular tubes used for this experiment are glass/epoxy (GFRP) composite tubes which are fabricated by the filament winding method. One edge of the composite tube is chamfered to reduce the initial peak load and to prevent catastrophic failure during crushing process. Energy absorption characteristics vary significantly according to the constituent materials, fabrication conditions, tube geometry and test condition. In tube geometry, according as inner diameter increase, unstable crush mode is caused by local buckling of delamination, but control of the fiber orientation should help composite tubes get stable crush mode.

• Steel and Composite Structures
• /
• v.23 no.1
• /
• pp.31-40
• /
• 2017

This article aims at presenting multi objective optimization of parameters that affect crashworthiness characteristics of bi-tubular structures using Taguchi method with grey relational analysis. To design the experiments, the $L_9$ orthogonal array has been used and based on that, the inner tubes have been fabricated by varying the three influence factors such as reference diameter, length difference and numbers of sides of the polygon with three levels, but all the outer cylinders have the same diameter and length 90 mm and 135 mm respectively. Then, the tailor made bi-tubular steel structures were subjected into quasi static axial compression. From the test results it is found that the crushing behaviors of bi-tubular structures with different combinations were fairly significant. The important responses (crashworthiness indicators) specific energy absorption and crush force efficiency have been evaluated from load - displacement curve. Finally optimal levels of parameters were identified using grey relational analysis, and significance of parameters was determined by analysis of variance. The optimum crashworthiness parameters are reference diameter 80 mm, length difference 0 mm and number of sides of polygon is 3, i.e., triangle within the selected nine bi-tube combinations.