• Title/Summary/Keyword: impact absorbing

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The Optimum Design according to System Variation of Impact Absorbing System for Spreader Considering Dynamic Characteristic (동특성을 고려한 스프레더용 충격흡수기의 시스템 변화에 따른 최적설계)

  • 안찬우;홍도관;김동영;한근조
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.6
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    • pp.230-237
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    • 2003
  • On this study, we operated the dynamic response for impact load of impact absorbing system for spreader by the finite element analysis and showed respectively the spring constant and the damping coefficient which the reaction force by impact was the lowest value for three types impact absorbing system according to the change of system, also we presented the change of impact reaction force according to the spring constant and the damping coefficient. Additionally, among the three types impact absorbing system according to the change of system, the reaction force of model II was the lowest value and the next model which has higher value than model II was model Iand model III has the highest value in the three types.

Optimum Design of Impact Absorbing System for Spreader by Vibration Analysis (진동해석에 의해 스프레더용 충격흡수기의 최적설계)

  • 홍도관;김동영;안찬우;한근조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.689-693
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    • 1997
  • This paper deals wth the impact and the transient analysis of the impact absorbing system consist of double damping. piston and sprlng system in spreader to increaas efficlcncy of it. It shows the optimum damping coefficient and spring constant under the limited stroku of Impact absorbing system using for crane spreader and the optimum condition of impact absorbing system causing certain reaction force as time. which is characteristic of dashpot and rubber. This system absorbed 11.5 and 88.5 % impact energq at the spring and the damper respectively.

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Impact Analysis Using Shock Absorbing System For Spreader (스프레더용 충격흡수장치를 통한 충격해석)

  • 김성윤;한동섭;심재준;한근조;안찬우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.745-748
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    • 2002
  • Many malfunctions take place in container crane spreader due to impact. So we designed a 2DOF hydraulic impact absorbing system and studied the change of impulse with respect to the variation of falling height and weight. The falling height becomes higher than 1m and the falling weight goes up heavier than 100kg, the impact absorbing rate was lower. When spreader is bumped against container and impulse force concentrates on one point, impact absorbing equipment would not be operated properly and make some trouble.

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Optimum Design of Impact Absorbing System for Spreader by Using a Design of Experiments (실험계획법을 이용한 스프레더용 충격흡수기의 최적설계)

  • 노영희;홍도관;김동영;안찬우;한근조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1529-1532
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    • 2003
  • This paper deals with the impact analysis of the impact absorbing system consist of one degree of freedom and two degree of freedom damping-spring system in spreader to increase efficiency of it. It shows the optimum damping coefficient and spring constant of impact absorbing system using for crane spreader and the optimum condition of impact absorbing system causing certain contact impulse. In the optimal model, the contact impulse is reduced 98.57 percent and 92.22 percent respectively.

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Evaluation of the Absorbing Performance of Radar-absorbing Structure with Periodic Pattern after the Low-velocity Impact (주기패턴 레이더 흡수 구조의 저속충격 후 흡수 성능 평가)

  • Joon-Hyung, Shin;Byeong-Su, Kwak
    • Composites Research
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    • v.35 no.6
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    • pp.469-476
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    • 2022
  • In this paper, the microwave absorbing characteristics after the impact of the radar-absorbing structure (RAS) consisting of periodic pattern sheet (PPS) and glass fiber-reinforced plastic (GFRP) were experimentally investigated. The fabricated RAS effectively absorbed the microwave in the X-band (8.2-12.4 GHz). In order to induce the damage to the RAS, a low-velocity impact test with various impact energy of 15, 40, and 60 J was conducted. Afterward, the impact damage was observed by using visual inspection, non-destructive test, and image processing method. Moreover, the absorbing performance of intact and damaged RAS was measured by the free-space measurement system. The experiment results revealed that the delamination damage from the impact energy of 15 J did not considerably affect the microwave absorbing performance of the RAS. However, fiber breakage and penetration damage with a relatively large damaged area were occuured when the impact energy was increased up to 40 J and 60 J, and these failures significantly degraded the microwave absorbing characteristics of the RAS.

A Study on the Impact Absorbing Characteristics for Various Shape and Hardness of Cylindrical Rubber Structures (원주형 고무구조물의 형상과 재질변화에 따른 충격흡수특성)

  • Kim, Dong-Jin;Kim, Wan-Doo;Lee, Young-Shin
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.441-446
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    • 2004
  • Mechanical systems with rubber parts have been used widely in industry fields. The evaluation of the physical characteristics of rubber is important in rubber application. Rubber material is useful to machine component for excellent shock absorbing characteristics. The impact characteristics of rubber were examined by experimental and finite element method. The impact test was conducted with a free-drop type impact tester. The ABAQUS/Explicit was used for finite element analysis. The effects of thickness and diameter of the cylindrical rubber structures were investigated. The impact absorbing ratio of the rubber material was studied order to compare the peak reaction force of the specimen which only contained aluminum against the specimen with the inserted rubber part.

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A STUDY ON EXPERIMENTAL CHARACTERISTICS OF ENERGY ABSORPT10N CONTROL IN THIN-WALLED TUBES FOR THE USE OF VEHICULAR- STRUCTURE MEMBERS

  • Kim, S.-K.;Im, K.-H.;Hwang, C.-S.;Yang, I.-Y.
    • International Journal of Automotive Technology
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    • v.3 no.4
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    • pp.137-145
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    • 2002
  • Automobiles should be designed to meet the requirements and standards for the protections of passengers in a car accident. One of safety factors is an absorbing capacity in collision. Many vehicles have been designed based on the criterion of the absorbing capacity. Therefore a controller has been developed in order to control and increase the absorbing capacity of impact energy in automobile collision. The capacity of impact energy will be improved regardless of vehicular-structure members and shapes. An air-pressure horizontal impact tester for crushing has been built up for the evaluation of energy absorbing characteristics in collision. Influence of height, thickness and clearance in the controller have been considered to predict and control the energy absorbing capacity. Aluminum alloy (Al) tubes (30,39,44 m in inner dia. and 0.8, 1.0, 1.2 m in thickness) are tested by axial loading. The energy absorbing capacity of Al tubes have been estimated in cases of with-controller and without-controller. respectively based on height. thickness, clearance of an controller.

The Study on the Impact Absorbing Behaviour of Steering Column (스티어링 컬럼의 충격 흡수 거동에 관한 연구)

  • Heo, Sin;Gu, Jeong-Seo;Choe, Jin-Min
    • 연구논문집
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    • s.25
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    • pp.23-29
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    • 1995
  • Steering column is a typical component that may injure the driver at a frontal collision accident. To protect the driver from an impact, it is very important to study the impact absorbing behaviour of steering column. The dynamic simulation were performed for the ball sleeve type impact absorbing steering column. The simulation results show similar trends to FMVSS 203 test results. Hence using the simulation program developed in this study, it is possible to predict dynamic response of steering system which is used in design modification. Impact absorbing performance of the ball sleeve type steering column with the column angle of $21^\circC$ and $26^\circC$ satisfies the safety criterion of FMVSS 203.

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Impact Analysis For a 2-DOF Shock Absorbing System with Multi-Step Damping Coefficient (다단계 감쇠계수를 갖는 2자유도계 충격흡수장치의 충격해석)

  • 김성윤;심재준;한동섭;안성찬;한근조;안찬우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.871-874
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    • 2002
  • Many malfunctions take place in container crane spreader due to impact. So we designed a 2DOF hydraulic impact absorbing system with multi-step damping coefficient and studied the effect of orifice's interval and damping coefficient. The damping coefficient of upper piston was found to be 180 N.s/m, and the orifice's interval to be 9mm, the max reaction force and the average reaction force might be lowest. Compared with a general 2-DOF impact absorbing system, the max reaction force reduced by 46%., and average reaction force reduced by 5%.

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A study on impact collapse characteristics of CFRP thin-walled laminates under high temperatures and hygrothermals (고온 고습하에서 CFRP 적층 원통부재의 충격 압궤특성)

  • 김정호;곽훈이;양인영
    • Journal of the Korean Society of Safety
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    • v.13 no.2
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    • pp.30-38
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    • 1998
  • In this study, in order to measure energy-absorbing characteristics in impact test of CFRP thin-walled laminates and interpret the cause of decreasing age when collapse test is carried out under the environments of high temperatures and hygrothermals, the moisture absorbing behavior according to the variety of orientation angle is observed and impact collapse characteristics of no moisture absorbing status is compared with that under the environments of high temperatures and hygrothermals. Especially, we try to obtain quantitative design data to develop CFRP thin-walled laminates with energy characteristics of optimum impact absorbing. The value of the maximum loading, mean loading, rate of energy absorption energy per unit volume and mass in CFRP thin-walled laminates on the high temperatures and hygrothermals is measured much lower than under no moisture absorbing. The maximum collapse loading in dynamic impact test is taken measurements lower than in static collapse test CFRP circular laminates in high temperatures and hygrothermals. But the absorbed energy per unit mass and volume is almost same each other and the biggest amount of energy is shown in CFRP circular laminates with orientation angle of $15^{\circ}$. Therefore, in the case of using CFRP circular laminates with axisymmetric mode, CFRP thin-walled structural members with orientation angle of $10^{\circ}$, $15^{\circ}$ has generally best condition.

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