• Title/Summary/Keyword: Tensile Strength

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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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    • 2010.03a
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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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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 Tensile Strength According to Various Output Conditions of PLA+ Materials Using 3D Printing (3D 프린팅을 이용한 PLA+ 소재의 다양한 출력 조건에 따른 인장강도에 대한 연구)

  • Na, D.H.;Kim, S.G.
    • Transactions of Materials Processing
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    • v.31 no.2
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    • pp.89-95
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    • 2022
  • 3D printing products manufactured by material extrusion are used in many industrial fields recently. However, these products are difficult to use in the field due to their low tensile strengths. In order to solve this problem, research on improving the tensile strength of the output using a 3D printer has been continuously conducted. In this study, we performed a tensile test using Universal Testing Machine according to infill pattern, nozzle temperature, bed temperature, and printing speed conditions. Results revealed that tensile specimen of concentric shape had the highest tensile strength in infill pattern condition and that the tensile strength increased linearly with increasing nozzle and bed temperatures. However, the tensile strength decreased with increasing printing speed. Consequently, we confirmed that tensile strength could be increased and decreased depending on output conditions of 3D printing.

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.

A Study on Tensile Strength of the 3D Printing Product According to the Nitrogen Concentration of Chamber Inside (챔버 내부의 질소 농도에 따른 3D프린팅 출력물의 인장 강도에 관한 연구)

  • Lee, Song Yeon;Huh, Yong Jeong
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.1
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    • pp.103-107
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    • 2022
  • Scaffolds are the structures that safely protect sensors in various parts of the body. Because of scaffolds must protect sensors from load, the tensile strength of the scaffolds must be higher than 750 kgf/cm2. Currently, the tensile strength of scaffolds made with the 3d printer is 714 kgf/cm2. We confirm that the tensile strength of the scaffolds increase using air with high nitrogen concentration. In this study, we conducted experiments to find nitrogen concentrations in which the tensile strength of the specimen is higher than 750 kgf/cm2. The nitrogen control device and the nitrogen concentration sensor were installed in the chamber type 3d printer. The nitrogen concentration inside the 3d printer was changed by 5 % from 80 % to 100 %. Specimens of ASTM D 638 standard were produced under changed nitrogen concentration. We measured the tensile strength of specimens. We compared the tensile strength of specimens produced under each nitrogen concentration. We confirmed that when air with nitrogen concentration of 90 % was used, the tensile strength of scaffolds were 762 kgf/cm2.

A Experimental Study on High Temperature Tensile Property of High Strength Steel (고강도강재의 고온인장특성에 관한 실험적 연구)

  • 장경호;이진형;신영의
    • Proceedings of the KWS Conference
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    • 2003.05a
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    • pp.260-262
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    • 2003
  • In this study, high temperature tensile properties of high tensile strength steels(POSTEN60, POSTEN80) were investigated by elevated temperature tensile test. According toe the results, high temperature tensile strength of POSTEN60 deteriorated slowly to 100$^{\circ}C$. As the temperature went up the tensile strength became better because of blue shortness and it deteriorated radically after reached to the maximum value around 300$^{\circ}C$. For the POSTEN80, high temperature tensile strength deteriorated slowly to 200$^{\circ}C$.As the temperature went up the tensile strength became better and it deteriorated slowly to 600$^{\circ}C$ after reached to the maximum value around 300$^{\circ}C$. Strain of high tensile strength steels at the elevated temperature increased radically after the mercury rose to 600$^{\circ}C$. The strain hardening ratio of POSTEN60 was larger then that of POSTEN80 at the elevated temperature as in the case at the room temperature and it became smaller radically after the mercury rose to 400$^{\circ}C$.

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A Study on the High Temperature Tensile Property and the Characteristics of Residual Stress in Welds of High Strength Steels (고강도강재의 고온인장특성 및 용접시 잔류응력특징에 관한 연구)

  • 장경호;이진형;신영의
    • Journal of Welding and Joining
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    • v.22 no.4
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    • pp.50-58
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    • 2004
  • In this study, high temperature tensile properties of high strength steels(POSTEN60, POSTEN80) were investigated. The three-dimensional thermal elastic-plastic analyses were conducted to investigate the characteristics of welding residual stresses in welds of high strength steels on the basis of thermal and mechanical properites at high temperature obtained from the experiment. According to the results, high temperature tensile strength of POSTEN60 steel deteriorated slowly to 10$0^{\circ}C$. As the temperature went up, the tensile strength became better because of blue shortness, and it deteriorated radically after reaching to the maximum value around 30$0^{\circ}C$. For the POSTEN80 steel, high temperature tensile strength deteriorated slowly to 20$0^{\circ}C$. As the temperature went up the tensile strength became better and it deteriorated slowly to $600^{\circ}C$ after reached to the maximum value around 30$0^{\circ}C$. Strain of high strength steels at the elevated temperature increased radically after the mercury rose to $600^{\circ}C$. The strain hardening ratio of POSTEN60 steel was larger then that of POSTEN80 steel at the elevated temperature as in the case at the room temperature and it became smaller radically after the mercury rose to 40$0^{\circ}C$. And, in the welding of high strength steels, increasing tensile strength of the steel (POSTEN60

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.