• 항공우주시스템공학회지
• /
• 제4권3호
• /
• 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%.

• 한국자동차공학회논문집
• /
• 제4권3호
• /
• pp.83-91
• /
• 1996

This paper investigates the energy absorption characteristics of thin-walled rectangular tubes. In the compact mode, the crushing process of a thin-walled tube is analyzed into 3 parts by the ratio of outward to inward fold length. The mean crush load and the half-wave folding length are determined by using minimum energy principle. The effective crush distance can be determined when half-wave folding length is known, and the number of folds is derived when crush distance is given. Thus when the crush distance is given, energy absorption capacity can be estimated with mean crush load and number of folds. And the theoretical value is proven experimentally.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 추계학술대회 논문집
• /
• 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.

• 한국자동차공학회논문집
• /
• 제6권5호
• /
• pp.119-127
• /
• 1998

Assuming that the static loaded square tube and the dynamic loaded one have no difference in their characteristics of the crush distance, the theoretical mean dynamic crush load was calculated with respect to the impact speed considering the strain rate sensitivity of the material. The ratio of dynamic to static mean crush load was predicted with previous results. The theoretical analysis was compared with the experimental results of aluminum square tubes axially loaded dynamically.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2000년도 춘계학술대회 논문집
• /
• 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.

• 대한세포병리학회지
• /
• 제10권1호
• /
• pp.73-78
• /
• 1999

Myxopapillary ependymoma generally arise in the conus medullaris and filum terminale of adult spinal cord. These tumors are readily recognized due to unique histopathologic features, however, their cytologic features are not well described. When only a tiny sample is obtained, cytologic examination using crush preparation may be a useful diagnostic tool to help appropriate intraoperative diagnosis. We present the crush cytologic features of myxopapillary ependymoma arising in thoracic and lumbar spinal cord of a 13-year-old boy. The patient had complained of paraparesis and back pain for 1 month. The MRI image revealed a relatively well demarcated intramedullary mass in T11-L1 levels. Crush preparation for cytology were peformed by biopsy material. Crush cytologic findings revealed high cellularity and small sized branching papillary clusters on fibrillary or mucinous background. The tumor cells had uniform round or elongated nuclei. The cytoplasmic process of tumor cells were attached to the vascular wall. Between the tumor cells and vascular walls, the perivascular collar of globoid acellular stroma with metachromatic reaction on toluidin blue stain was noted. The crush preparation of myxopapillary ependymoma is considered as a simple and highly accurate diagnostic tool for differentiation from other intramedullary neoplasms of central nervous system.

• 한국압력기기공학회 논문집
• /
• 제8권2호
• /
• pp.7-13
• /
• 2012

A spacer grid which is one of the most important structural components in a pressurized water reactor fuel is an interconnected array of slotted grid straps, welded at the intersections to form an egg-crate structure. The spacer grid is required to not only protect fuel rods stably but also have sufficient lateral crush strength for the sake of enabling shut-down of the nuclear reactor during abnormal operating environments. Then, the lateral crush strength of the spacer grid is closely related with welding quality of the spacer grid. Previous research on the crush strength analysis of the spacer grid had been performed using only parent material properties. In this study, to investigate the effect on the crush strength of the spacer grid when used mechanical properties in weld zone instead of parent material properties, crush strength analysis considering mechanical properties in weld zone obtained from the instrumented indentation technique was performed and compared the results with the previous research.

• 한국방재안전학회논문집
• /
• 제16권1호
• /
• pp.49-60
• /
• 2023

2022년 10월 29일 발생한 이태원 참사 이후 군중압박 사고로 인한 인명피해에 대한 관심이 높아졌으나 국내에서 군중압박과 관련된 학술적, 실제적 기반이 미약함이 지적되었다. 이에 본 연구에서는 군중압박과 관련된 용어와 개념을 조사하고 가능한 한글 용어 후보들을 제안하였으며, 국내외에서 발생한 대표적인 군중압박 사고 사례를 조사하여 정리하였다. 일부 대표적 사례를 기반으로 한 선진국의 접근법들을 조사하였고, 그 중 대표적으로 영상분석, 시뮬레이션 및 설문과 인터뷰 방법을 요약 도출하였다. 이를 통하여 군중압박 사고의 한글 용어 표준화와 개념 정립, 평가 및 접근 방법의 체계화가 이루어지기를 기대하고 있다.

• 한국자동차공학회논문집
• /
• 제4권6호
• /
• pp.216-222
• /
• 1996

This paper presents a computational technique to predict roof crush resistance in early design stage of passenger car development. This technique use a simple F.E. model with nonlinear spring elements which represent plastic hinge behavior at weak areas. By assuming actual sections as equivalent simple sections, maximum bending moments which weak areas in major members can stand are theoretically calculated. Results from prediction of roof crush resistance are correlated well with test results.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
• /
• pp.455-458
• /
• 2005

This study compares the concrete using natural sand with the concrete using crush sand for the examination for the properties of a concrete. In the fresh concrete, the concrete using crush sand has less of the quantity of consistency, the content of air, and bleeding than the concrete using natural sand, and the concrete using crush sand has faster setting time than the concrete using natural sand. In hardening concrete, the concrete using crush sand has higher compressive strength and tensile strength than the concrete using natural sand because minute particles fill up a gap. Drying shrinkage of the concrete using natural sand is less than the concrete using crush sand.