• 제목/요약/키워드: dynamic compressive behavior

검색결과 112건 처리시간 0.023초

Dynamic Deformation Behavior of Aluminum Alloys Under High Strain Rate Compressive/Tensile Loading

  • Lee, Ouk-Sub;Kim, Guan-Hee;Kim, Myun-Soo;Hwang, Jai-Sug
    • Journal of Mechanical Science and Technology
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    • 제17권6호
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    • pp.787-795
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    • 2003
  • Mechanical properties of the materials used for transportations and industrial machinery under high strain rate loading conditions such as seismic loading are required to provide appropriate safety assessment to these mechanical structures. The Split Hopkinson Pressure Bar (SHPB) technique with a special experimental apparatus can be used to obtain the material behavior under high strain rate loading conditions. In this paper, dynamic deformation behaviors of the aluminum alloys such as A12024-T4, A1606 IT-6 and A17075-T6 under both high strain rate compressive and tensile loading conditions are determined using the SHPB technique.

Compressive behavior of concrete under high strain rates after freeze-thaw cycles

  • Chen, Xudong;Chen, Chen;Liu, Zhiheng;Lu, Jun;Fan, Xiangqian
    • Computers and Concrete
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    • 제21권2호
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    • pp.209-217
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    • 2018
  • The dynamic compressive behavior of concrete after freezing and thawing tests are investigated by using the split Hopkinson pressure bar (SHPB) technique. The stress-strain curves of concrete under dynamic loading are measured and analyzed. The setting numbers of freeze-thaw cycles are 0, 25, 50, and 75 cycles. Test results show that the dynamic strength decreases and peak strain increases with the increasing of freeze-thaw cycles. Based on the Weibull distribution model, statistical damage constitutive model for dynamic stress-strain response of concrete after freeze-thaw cycles was proposed. At last, the fragmentation test of concrete subjected to dynamic loading and freeze-thaw cycles is carried out using sieving statistics. The distributions of the fragment sizes are analyzed based on fractal theory. The fractal dimensions of concrete increase with the increasing of both freeze-thaw cycle and strain rate. The relations among the fractal dimension, strain rates and freeze-thawing cycles are developed.

플라스틱 SHPB를 사용한 고무의 고변형률 하중하에서의 동적변형 거동 (Dynamic deformation behavior of rubber under high strain rate compressive loading)

  • 이억섭;김경준
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.849-853
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    • 2002
  • A specific experimental method, the split Hopkinson pressure bar (SHPB) technique has been widely used to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of 103/s~104/s. In this paper, dynamic deformation behaviors of rubber materials widely used for the isolation of vibration from varying structures under dynamic loading are determined using a Split Hopkinson Pressure Bar technique.

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0.15C-0.2Si-0.5Mn 저탄소강의 동적 재결정 거동에 미치는 Nb 첨가와 공정 변수의 영향 (Effect of Nb Contents and Processing Parameters on Dynamic Recrystallization Behavior of 0.15C-0.2Si-0.5Mn Low-Carbon Steels)

  • 이상인;서하늘;이재승;황병철
    • 열처리공학회지
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    • 제29권5호
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    • pp.209-215
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    • 2016
  • In this study, the effect of Nb contents and processing parameters on dynamic recrystallization behaviour of 0.15C-0.2Si-0.5Mn low-carbon steels was investigated. Three kinds of steel specimens with different Nb contents were fabricated and then high-temperature compressive deformation test was conducted by varying reheating temperature (RT), deformation temperature (DT), and strain rate (SR). The Nb2 and Nb4 specimens containing Nb had smaller prior austenite grain size than the Nb0 specimens, presumably due to pinning effect by the formation of carbides and carbonitrides precipitates at austenite grain boundaries. The high-temperature compressive deformation test results showed that dynamic recrystallization behavior was suppressed in the specimens containing Nb as the strain rate increased and deformation temperature decreased because of pinning effect by precipitates, grain boundary dragging effects by solute atoms, although the compressive stress increased with increasing strain rate and decreasing deformation temperature.

SHPB 기법에서 Pusle shpaer 가 내유 고무(NBR)의 동적 변형 거동에 미치는 영향 (Effect of pulse shaper in SHPB technique on dynamic deformation behavior of an NBR rubber)

  • 김성현;이억섭;이종원
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.634-637
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    • 2004
  • This paper presents a Split Hopkinson Pressure Bar(SHPB) technique to obtain compressive stress-strain data for rubber materials. An experimental technique that modifies the conventional Split Hopkinson Pressure Bar(SHPB) has been developed for measuring the compressive stress-strain responses of materials with low mechanical impedance and low compressive strengths such as rubber. This paper introduces an all-polymeric pressure bar which achieves a closer impedance match between the pressure bar and the specimen materials. In addition, we are a pulse shaper to lengthen the rising time of the incident wave to ensure stress equilibrium and homogeneous deformation of a rubber materials. It is found that the modified technique can be determine the dynamic deformation behavior of an NBR rubber more accurately.

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플라스틱 SHPB기법을 사용한 고무의 고변형률 하중 하에서의 동적변형 거동 (Dynamic Deformation Behavior of Rubber Under High Strain-Rate Compressive Loading by Using Plastic SHPB Technique)

  • 이억섭;김경준
    • 한국정밀공학회지
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    • 제20권11호
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    • pp.158-165
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    • 2003
  • A specific experimental method, the Split Hopkinson pressure bar (SHPB) technique has been widely used to determine the dynamic material properties under the impact compressive loading conditions with strain rate of the order of 10$^3$/s∼l0$^4$/s. In this paper, dynamic deformation behaviors of rubber materials widely used for the isolation of vibration from structure under varying dynamic loading are determined by using plastic SHPB technique. A transition point to scope with the dynamic deformation behavior of rubber-like material is defined in this paper and used to characterize the specifics of the dynamic deformation of rubber materials.

SHPB 기법을 사용한 고변형률 속도 하중하에서의 합성수지의 동적 변형 거동 (Dynamic deformation behavior of Ethylene Copolymer under high strain rate compressive loading)

  • 이종원;이억섭;황시원;김성현
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.371-376
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    • 2004
  • It is well known that a specific experimental method such as the Split Hopkinson Pressure Bar (SHPB) technique is the simplest experimental technique to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of $10^3/s{\sim}10^4/s$. This type of experimental procedure has been widely used with proper modification on the test setups to determine the varying dynamic response of materials for the dynamic boundary conditions such as tensile and fracture as well. In this paper, dynamic compressive deformation behaviors of an Ethylene Copolymer materials widely used for the isolation of vibration from varying structures under dynamic loading are estimated using the SHPB technique.

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SHPB기법을 사용한 고무와 합성수지의 고변형률 속도 하중 하에서의 동적 변형 거동 (Dynamic Deformation Behavior of Rubber and Ethylene Copolymer Under High Strain Rate Compressive Loading)

  • 이억섭;이종원;김경준
    • 한국정밀공학회지
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    • 제21권6호
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    • pp.122-130
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    • 2004
  • It is well known that a specific experimental method, the Split Hopkinson Pressure Bar (SHPB) technique is a best experimental technique to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of 10$^3$/s∼10$^4$/s. This type of experimental procedure has been widely used with proper modification on the test setups to determine the varying dynamic response of materials for the dynamic boundary conditions such as tensile and fracture as well. In this paper, dynamic compressive deformation behaviors of a rubber and an Ethylene Copolymer materials widely used for the isolation of vibration from varying structures under dynamic loading are estimated using a Split Hopkinson Pressure Bar technique.

동적하중 하에서 석회암의 변형 및 파괴거동에 관한 실험적 연구 (Experimental Study on Deformation and Failure Behavior of Limestones under Dynamic Loadings)

  • 강명수;강형민;김승곤;천대성;;조상호
    • 터널과지하공간
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    • 제22권5호
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    • pp.339-345
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    • 2012
  • 동적하중 하에서 암석의 변형거동 및 파괴강도는 발파, 지진 또는 암반돌출의 지진동에 의한 지하구조물의 안정해석에 중요하다. 본 연구에서는 스플릿 홉킨슨 압력봉(SHPB) 충격실험시스템을 석회암시료의 일축압축시험과 압열인장시험에 적용하여 고변형률과 동적강도 평가를 수행하였다. 충격봉의 발사속도를 제어하여 파괴강도 이하 동적응력 상태에서의 석회암시료의 동적응력-변형거동을 분석하였다. 시료 내 파괴여부 및 파괴양상을 파악하기 위하여 Micro-focus X-ray 단층촬영을 수행하였다. 동적 압축강도 실험결과, 석회암시료의 동적압축강도는 변형율속도 의존성을 보였으며, 동적 압축파괴강도는 140 MPa 이상으로 평가되었다. 동적 압열 인장 실험결과, 석회암시료의 동적 압열인장강도는 21 MPa 이상으로 정적 압열인장강도보다 3배 이상 높은 것으로 평가되었다.

상용 알루미늄 합금의 고속 인장/압축 변형거동 규명 (Dynamic deformation behavior of aluminum alloys under high strain rate compressive/tensile loading)

  • 이억섭;김관희;김면수;황시원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집A
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    • pp.268-273
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    • 2000
  • Mechanical properties of the materials used for transportations and industrial machinery under high strain rate loading conditions are required to provide appropriate safety assessment to these mechanical structures. The Split Hopkinson Pressure Bar(SHPB) technique, a special experimental apparatus, can be used to obtain the material behavior under high strain rate loading condition. In this paper, dynamic deformation behaviors of the aluminum alloys, Al2024-T4, Al6061-T6 and Al7075-T6, under high strain rate compressive and tensile loading are determined using SHPB technique.

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