• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2007년도 춘계학술대회논문집
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• pp.272-278
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• 2007

• 한국포장학회지
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• 제7권2호
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• pp.43-51
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• 2001

This study was carried out to analyze changes of the physical properties of corrugated fiberboard boxes for fruits packaging by various moisture and temperature changes. There were significant decrease in burst strength with increased relative humidity. And also compressive strength(ring crush test) of corrugated fiberboard and box were reduced with moisture content. The decreasing amounts of single wall(SW) corrugated fiberboard was bigger than that of double wall(DW). The physical properties reductions of corrugated fiberboard and box were mainly affected by relative humidity. Therefore, it is suggested that development of the water-resistant corrugated fiberboard and box be useful under the condition of low temperature and high relative humidity such as the cold chain system.

• 펄프종이기술
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• 제31권3호
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• pp.47-53
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• 1999

The effect of coating of liner components with oxidized starch on the properties of corrugated box was examined . Coating was carried out on liner components of B flute, single-wall corrugated board(SK180/S120/K200) , and corrugated box was made from the treated corrugated board. Box was made in a regular slotted container (RSC) style, and box compression strength was determined in the direction of top-to-bottom compression. The compression strength of box coated on outside liner component showed 15.4% improvement for 1.58g㎡ coating. On the other hand, the strength of box coated on outside liner component showed only 1.45% improvement for 1.41g/㎡ coating and 3.46% improvement for 2.32g/㎡ coating. Coating on inside liner component with oxidized starch at low coating weight more significantly improved box compression strength than coating on outside liner component, and the improvement was marked at the coating weight of 1.5-2.5g/㎡. In estimating top-to-bottom box compression strength, the experimental values were closer to the calculated values from McKee's equation suing edgewise compression strength of the combined board measured by column crush test than those from Kellicutt's equation using compression strength of component paperboards measured by ring crush test.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1391-1398
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• 2009

The vibrating table method is widely used to estimate the minimum void ratio $e_{min}$. The existing method recommended in ASTM and KS F, however, can not consider the particle crushing during the vibrating table test. In this study, the particle cursing phenomenon was investigated by comparing vibrating table test with pluviation method using artificial sand (K-7). Vibrating table test for the artificial sand was confirmed which can crush of particle during the test. This study demonstrates that vibrating table test is an ineffective method to produce the more reliable $e_{min}$ of artificial sand.

• 한국농공학회논문집
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• 제48권6호
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• pp.59-67
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• 2006

Particles of soil are crushed when soil is compacted in the in-situ or lab. Among many factors that affect the crush of particles, compaction energy is a major factor. Because the crush of particles can change physical properties, the analysis of effect of compaction energy is very important. In this study, the fragmentation fractals were used for determining the change in grain size distribution and the effect due to change in grain size distribution was estimated. Compaction energy was increased by 50, 100, 200 and 300% based on the energy of standard A compaction test. As a result, grain size distribution curves were changed and fine particles increased as compaction energy were increased. Relative compaction were ranged between $93.38{\sim}107.67$. Fractal dimension of each site increased as compaction energy increased. Relative compaction is proportional to the fractal dimension but coefficients of permeability were in inverse proportional to the involution of fractal dimension.

• Steel and Composite Structures
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• 제23권1호
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• pp.31-40
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• 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.

• 대한안전경영과학회지
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• 제4권2호
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• pp.189-197
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• 2002

Composites have wide applications in aerospace vehicles and automobiles because of the inherent flexibility in their design lot improved material properties. Composite tubes 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 fibers, in the matrix and in the fiber-matrix interface in tension, compression and shear. The purpose of this study is to investigate the energy absorption characteristics of Gr/E(Graphite/Epoxy) tubes on static and impact tests. The collapse characteristics and energy absorption of a variety of tubes have been examined. Changes in the lay-up which increased the modulus increased the energy absorption of the tubes. Based on the test results, the following remarks can be made: Among CA15, CA00 and CA90 curves the CA90 tube exhibits the highest crush load throughout the whole crush process, and max load increases as interlaminar number increase. Among all the tubes type CC90 has the largest specific crushing stress of 52.60 kJ/kg which is much larger than other tubes.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.121-124
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• 2005

As a countermeasure about that, in this situation that suggest utilizing mixed drush sand and particle washed sand, this study is reviewing and comparing, as a experimental and positive test, mixed both workability and engineering properties of mortar, The purpose of this study make a suggestion that is fundamental data for utilizing mixed crush sand and particle washed sand.

• 자동차안전학회지
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• 제13권4호
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• pp.26-32
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• 2021

This study is intended to augment the Roof strength test being evaluated by IIHS (Insurance Institute for Highway Safety). In order to find solutions for increasing Roof Crashworthiness Evaluation SWR (Strengthto-weight ratio). This study introduces that Integrated Connection Structure Between Center Pillar and Roof Center Rail is proposed as a critical solution.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.471-476
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• 2001

The main object of this study is to develop a reliable FEM simulation technique for stability test using ABAQUS software and to clarify the effect of base profile of a steel D&I(drawn and ironed) can on the dome reversal pressure. For the can after body making simulation, two kind of stability test, dome buckle test and axial crush test are performed. The factors studied in the base profile on the dome reversal pressure are the base diameter, the rim radius, the dome shoulder radius, the dome radius and the dome depth. Within the limits before the occurrence of normal snap-through buckling of dome, the dome reversal pressure is improved by decreasing the base diameter, increasing the dome depth or increasing the dome shoulder depth.