• Title, Summary, Keyword: Tensile Strength

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Tensile strength of unidirectional CFRP laminate under high strain rate

  • Taniguchi, Norihiko;Nishiwaki, Tsuyoshi;Kawada, Hiroyuki
    • Advanced Composite Materials
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    • v.16 no.2
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    • pp.167-180
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    • 2007
  • The tensile strength of unidirectional carbon fiber reinforced plastics under a high strain rate was experimentally investigated. A high-strain-rate test was performed using the tension-type split Hopkinson bar technique. In order to obtain the tensile stress-strain relations, a special fixture was used for the impact tensile specimen. The experimental results demonstrated that the tensile modulus and strength in the longitudinal direction are independent of the strain rate. In contrast, the tensile properties in the transverse direction and the shear properties increase with the strain rate. Moreover, it was observed that the strain-rate dependence of the shear strength is much stronger than that of the transverse strength. The tensile strength of off-axis specimens was measured using an oblique tab, and the experimental results were compared with the tensile strength predicted based on the Tsai-Hill failure criterion. It was concluded that the tensile strength can be characterized quite well using the above failure criterion under dynamic loading conditions.

A Study on the Seam Strength and Resistance to Slippage of Yarns of Lining Fabrics (의류 안감의 봉합강도 및 실 미끄럼저항에 관한 연구)

  • Uh, Mi-Kyung;Park, Myung-Ja
    • Fashion & Textile Research Journal
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    • v.7 no.4
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    • pp.433-438
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    • 2005
  • Seven commercial lining fabrics normally used in a market were selected: plain-weave fabrics with polyester, nylon, rayon and acetate fiber, and polyester textured yarn, in addition, polyester fabrics with plain, twill and satin weave. Then seam strength, seam efficiency, resistance to slippage of yarns and type of seam destruction were examined related to endurance by textiles in sewing capability of the lining fabrics. In results, as tensile strength was greater, seam strength got greater, which shows tensile strength and seam strength have close relationship. Tensile and seam strength of acetate fabric were the least, but seam efficiency was the greatest. It presents that strong tensile and seam strengths do not show high seam efficiency at the same time. Various types of seam destruction have been shown. When tensile strength of the sewing thread was greater than tensile strength of fabric, fabric destruction was occurred before the sewing thread destruction. When tensile strength of the fabric was greater than seam strength, the sewing thread destruction was occurred. Resistance to slippage of yarns got greater as tensile strength of the fabric got greater. The plain-weave fabric, which tensile strength of fabric was smaller, showed the greater resistance to slippage of yarns than twill and satin weave fabrics. The stretch fabric revealed the optimal lining fabric with the greatest resistance to slippage of yarns.

Fatigue Strength Evaluation of the Clinch Joints of a Cold Rolled Steel Sheet

  • Kim, Ho-Kyung
    • International Journal of Railway
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    • v.2 no.4
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    • pp.131-138
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    • 2009
  • Static tensile and fatigue tests were conducted using tensile-shear specimens to evaluate the fatigue strength of a SPCC sheet clinch joint. The maximum tensile strength of the specimen produced at the optimal punching force was 1750 kN. The fatigue endurance limit (=760 N) approached 43% of the maximum tensile load (=1750 N) at a load ratio of 0.1, suggesting that the fatigue limit is approximately half of the value of the maximum tensile strength. The FEM analysis showed that at the fatigue endurance limit, the maximum von-Mises stress of 373 MPa is very close to the ultimate tensile strength of the SPCC sheet (=382 MPa).

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Numerical simulation of compressive to tensile load conversion for determining the tensile strength of ultra-high performance concrete

  • Haeri, Hadi;Mirshekari, Nader;Sarfarazi, Vahab;Marji, Mohammad Fatehi
    • Smart Structures and Systems
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    • v.26 no.5
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    • pp.605-617
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    • 2020
  • In this study, the experimental tests for the direct tensile strength measurement of Ultra-High Performance Concrete (UHPC) were numerically modeled by using the discrete element method (circle type element) and Finite Element Method (FEM). The experimental tests used for the laboratory tensile strength measurement is the Compressive-to-Tensile Load Conversion (CTLC) device. In this paper, the failure process including the cracks initiation, propagation and coalescence studied and then the direct tensile strength of the UHPC specimens measured by the novel apparatus i.e., CTLC device. For this purpose, the UHPC member (each containing a central hole) prepared, and situated in the CTLC device which in turn placed in the universal testing machine. The direct tensile strength of the member is measured due to the direct tensile stress which is applied to this specimen by the CTLC device. This novel device transferring the applied compressive load to that of the tensile during the testing process. The UHPC beam specimen of size 150 × 60 × 190 mm and internal hole of 75 × 60 mm was used in this study. The rate of the applied compressive load to CTLC device through the universal testing machine was 0.02 MPa/s. The direct tensile strength of UHPC was found using a new formula based on the present analyses. The numerical simulation given in this study gives the tensile strength and failure behavior of the UHPC very close to those obtained experimentally by the CTLC device implemented in the universal testing machine. The percent variation between experimental results and numerical results was found as nearly 2%. PFC2D simulations of the direct tensile strength measuring specimen and ABAQUS simulation of the tested CTLC specimens both demonstrate the validity and capability of the proposed testing procedure for the direct tensile strength measurement of UHPC specimens.

A Study on the Strength of High-Silicon Aluminium Alloys at Elevated Temperatures (고규소(高珪素)-AI합금(合金)의 고온강도(高溫强度)에 관(關)한 연구(硏究))

  • Nam, Tae-Woon
    • Journal of Korea Foundry Society
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    • v.3 no.4
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    • pp.256-261
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    • 1983
  • In this study, the variations of tensile strength and yield strength of Al-20% Si alloy were studied. Copper, magnesium and nickel as alloying elements added from 1% to 3% respectively. The temperature range was from room temperature to $350^{\circ}C$. The refinement of primary silicon crystal was treated with phosphorous addition. The results obtained are as follows: 1. Tensile strnegth and yield strength showed more increased strength in refining treated alloy than that of in nonrefining alloy at elevated temperature. 2. Tensile strength and yield strength were increased with the contents of copper. Tensile strength showed the maximum at $150^{\circ}C$, but yield strength was decreased with increasing temperature. 3. The effect of magnesium addition on tensile strength and yield strength showed the maximum at 1% addition and $150^{\circ}C$. 4. Tensile strength and yield strength showed a slight increase with the content changes of nickel and they were decreased with increasing temperature.

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Effect of ground granulated blast furnace slag on time-dependent tensile strength of concrete

  • Shariq, M.;Prasad, J.
    • Computers and Concrete
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    • v.23 no.2
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    • pp.133-143
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    • 2019
  • The paper presents the experimental investigations into the effect of ground granulated blast furnace slag (GGBFS) on the time-dependent tensile strength of concrete. The splitting and flexural tensile strength of concrete was determined at the ages of 3, 7, 28, 56, 90, 150 and 180 days using the cylindrical and prism specimens respectively for plain and GGBFS concrete. The amount of cement replacement by GGBFS was 0%, 40% and 60% on the weight basis. The maximum curing age was kept as 28 days. The results showed that the splitting and flexural tensile strength of concrete containing GGBFS has been found lower than the plain concrete at all ages and for all mixes. The tensile strength of 40 percent replacement has been found higher than the 60 percent at all ages and for all mixes. The rate of gain of splitting and flexural tensile strength of 40 percent GGBFS concrete is found higher than the plain concrete and 60 percent GGBFS concrete at the ages varying from 28 to 180 days. The experimental results of time-dependent tensile strength of concrete are compared with the available models. New models for the prediction of time-dependent splitting and flexural tensile strength of concrete containing GGBFS are proposed. The present experimental and analytical study will be helpful for the designers to know the time-dependent tensile properties of GGBFS concrete to meet the design requirements of liquid retaining reinforced and pre-stressed concrete structures.

Influence of Rock Inhomogeneity on the Static Tensile Strength of Rock (암석의 정적 인장강도에 미치는 불균질성의 영향)

  • Cho, Sang-Ho;Yang, Hyung-Sik;Katsuhiko Kaneko
    • Tunnel and Underground Space
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    • v.13 no.2
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    • pp.117-124
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    • 2003
  • The fracture processes under static tensile loading were simulated using a proposed numerical simulation method, based on finite element method and fracture mechanism, and analyzed to verify an influence of rock inhomogeneity on static tensile strength. Static tensile strengths for the specimen models with different spatial microscopic tensile strength when m=5 and m=50 were estimated. These analyses revealed that the static tensile strength becomes closer to the mean microscopic tensile strength at a higher uniformity coefficient and the scatter of the strength data decreases in increasing the uniformity coefficients. Therefore, it could be concluded that rock inhomogeneity has an effect on static tensile strength.

Laboratory and Meta Analysis for 9% NI Steel of Liquified Natural Gas Carrier (LNG 저장 탱크 운반선 9% Ni Steel의 용접성에 대한 실험분석과 메타분석 연구)

  • Park, Sang Heup;Ahn, Duck Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.670-677
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    • 2016
  • Laboratory and meta-analyses were done for 9% NI Steel for use in a liquefied natural gas carrier. The meta-analysis is based on a previous study. The laboratory analysis examines the effects of a single pass and multiple passes on the tensile strength through an impulse-response test. The tensile strength increased from pass one to pass three and decreased from pass four to pass ten. The pass and multi-pass welding had a positive effect on the tensile strength. Lastly, the welding and tensile time had a positive effect on the tensile strength.

A study on direct tensile strength of cement soil (시멘트 혼합토의 인장강도에 관한 연구)

  • Kim, Chang-Woo;Park, Sung-Sik;Choi, Hyun-Seok
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.584-594
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    • 2010
  • It is difficult to prepare a specimen for directly testing a tensile strength of soils. Therefore, a tensile strength of soils has been measured indirectly. In this study, a mold and sample preparation tool for directly testing a tensile strength of soils has been developed and a tensile strength of weakly cemented sand was measured by using such device. A compressive strength of the cemented sand was also measured and its value was 30 times greater than its tensile strength.

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The Estimation of Dynamic/Impact Strength Characteristics of High Tensile Steel by Dynamic Lethargy Coefficient (동적무기력계수에 의한 고장력강의 동적.충격강도 특성 평가)

  • 송준혁;박정민;채희창;강희용;양성모
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.96-100
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    • 2002
  • The purpose of this paper is presented a rational method of predicting dynamic/impact tensile strength of high tensile steel materials widely used fur structural material of automobiles. It is known that the ultimate strength is related with the loading speed and the Lethargy Coefficient from the tensile test. The Dynamic Lethargy Coefficient is proportional to the disorientation of the molecular structure and indicates the magnitude of defects resulting from the probability of breaking the bonds responsible for its strength. The coefficient is obtained from the simple tensile test such as failure time and stresses at fracture. These factors not only affect the static strength but also have a great influence on the dynamic/impact characteristics of the joist and the adjacent structures. This strength is used to analyze the failure life prediction of mechanical system by virtue of its material fracture. The impact tensile test is performed to evaluate the life parameters due to loading speed with the proposed method. Also the evaluation of the dynamic/impact effect on the material tensile strength characteristics is compared with the result of Campbell-Cooper equation to verify the proposed method.