• Title/Summary/Keyword: 파열강도

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Effect of External Pressure on the Burst Strength of Steam Generator Tube (증기발생기 전열관의 파열강도에 미치는 외압의 영향)

  • Cho, Sung-Keun;Bae, Bong-Kook;Seok, Chang-Sung
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.353-358
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    • 2004
  • Tracing the study of the burst test of steam generator tube, few studies have been reported to effect of external pressure acting on secondary-side in service condition. In this study the burst tests of Inconel 690TT were conducted in order to evaluate burst strength characteristics under the effect of external pressure. We obtained the result that the burst strength of Inconel 690TT increased when external pressure increased while both total circumferential elongation and uniform burst elongation were not affected. Also, according to the increased of external pressure, the size of the burst opening became smaller and the tear was getting severe.

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Comparison of Cutting and Compression Tests for the Texture Measurement of Chinese Cabbage Leaves (절단시험과 압착시험에 의한 배추잎의 조직감 측정 비교)

  • Lee, Cherl-Ho;Hwang, In-Ju
    • Korean Journal of Food Science and Technology
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    • v.20 no.6
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    • pp.749-754
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    • 1988
  • The texture measurement of Chinese cabbage leaves used for Kimchi preparation were con ducted by cutting and compression test and the results were compared to the sensory evaluation. The cutting force of cabbage leaf stalk increased by blanching or salting, and a maximum cutting force was attained by salting in 15% salt solution for 5 hours. The compression force and recovered height measured by compression test of Chinese cabbage leaf stalk decreased by blanching or salting, and the breaking point disappeared. Treatment with $CaCl_2$ solution increased the cutting force compression force and breaking strength of fresh leaves, but the effect disappeared by salting or blanching. Cutting strength could be used as a parameter indicating the hardness and chewiness of salted cabbage. Compression force and breaking strength could indicate the textural changes of blanched leaves, but were not useful for the measurement of hardness and chewiness of salted leave.

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Wet and Dry Strengths, and Air Permeability of Seedling Plate Paper (육묘용 포트원지의 습윤 및 건조강도와 투기도)

  • Seo, Won-Sung;Park, Jong-Moon
    • Horticultural Science & Technology
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    • v.16 no.2
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    • pp.229-232
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    • 1998
  • This study was conducted to determine the properties of seedling plate papers currently used in commercial production, then to get basic information for manufacturing new seedling plate paper. Imported seedling plate paper had high wet tensile and burst strengths in its usage circumstances. Wet tensile strength was very high with 38.7% of dry tensile strength. Wet burst strength was also very high with 62.4% of dry burst strength. The seedling plate paper contained about 30% of synthetic fibers. It had 10 Gurley sec. in air permeability indicating effective movement of air. Seedling plate papers were' made in laboratory scale. For sufficient sizing degree, the addition of 0.5% AKD (alkylketene dimer) by weight was good enough. Additional amount of AKD more than 0.5% by weight caused strength loss even though improving sizing effect. The addition of wet strength reagent such as Finex-B 2% by weight resulted in good strength and air permeability.

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Dynamic Shear Strength of Stirrup-reinforced Cast-in Anchors by Seismic Qualification Tests (스터럽 보강 선설치 앵커의 지진모의실험에 의한 동적 전단 저항강도 평가)

  • Kim, Tae Hyung;Park, Yong Myung;Kang, Choong Hyun;Lee, Jong Han
    • Journal of Korean Society of Steel Construction
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    • v.30 no.2
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    • pp.67-76
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    • 2018
  • An experimental study was conducted to evaluate the breakout strength of stirrup-reinforced cast-in anchors under dynamic shear loadings. The shear loadings were applied in the manner specified in the ACI 355.2 and ETAG 001 for the seismic qualification tests. Test specimens were fabricated with M36 anchor (edge distance, 180mm) reinforced with D10 stirrups (spacing, 100mm). The specimens reached almost the breakout strength and thereafter fracture of anchor occurred. Additional tests with M42 anchor (edge distance, 160mm) reinforced with D6 bars (spacing, 100mm) were also conducted. The experimental results showed that the dynamic shear strength was not less than the static resistance. Based on the test results, it was shown that ACI 318 and ETAG 001 specifications estimate the breakout strength of stirrup-reinforced anchors conservatively as more reinforcement is provided.

Shear Resistance of CIP Anchors under Dynamic Loading: Unreinforced Anchor (선설치앵커의 동적 전단하중에 대한 저항강도: 비보강 앵커)

  • Park, Yong Myung;Kang, Moon Ki;Kim, Dong Hyun;Lee, Jong Han;Kang, Choong Hyun
    • Journal of Korean Society of Steel Construction
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    • v.26 no.1
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    • pp.11-20
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    • 2014
  • The Concrete Capacity Design(CCD) method has been used in the design of anchor since 2001 and Korean design code specify that concrete breakout capacity of CIP anchor under seismic load shall be taken as 75% of static capacity. In this study, an experimental study was performed to evaluate the concrete breakout capacity of unreinforced CIP anchors under dynamic shear force. For the purpose, three static and dynamic shear-loading tests were conducted using 20mm diameter anchors, respectively. The edge distance of 120mm was considered in the tests. In the dynamic tests, 15 cycles pulsating load with 1Hz speed was applied and the magnitude of loading step was increased until concrete breakout failure occurs. From the tests, the concrete breakout capacity under dynamic shear loading showed nearly same capacity by static loading.

Effect of Liner Component Coatings by Oxidized Starch on Properties of Corrugated Board (라이너지의 산화전분 코팅이 골판지의 물성에 미치는 영향)

  • Ahn, Byoung-Kuk;Ahn, Won-Yung
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.2
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    • pp.3-11
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    • 1998
  • Coating was carried out on liner components of B flute, single-wall corrugated board(SK180/S120/K200) to examine the effect of liner component coatings by oxidized starch on the properties of corrugated board. Both bursting strength and edgewise compression strength(ECS) of corrugated board were improved by coating of its liner components with oxidized starch. Bursting strength of corrugated board rapidly increased with an initial increase of coating weight, but as the coating weight further increased, there was no increase in bursting strength. The results showed 30.3% improvement for $2.32g/m^2$ coating on outside liner component, 36.8% improvement for $4.84g/m^2$ coating on inside liner component and 39.9% improvement for $7.16g/m^2$ coating on both liner components in bursting strength of corrugated board. Regardless of treated liner components, ECS of corrugated board was improved by coating of oxidized starch, and especially greater improvement was accomplished when corrugated board was coated on inside liner component or both liner components at low level of coating weight - 11.3% improvement for $1.58g/m^2$ coating on Inside liner component and 11.9% improvement for $2.99g/m^2$ coating on both liner components.

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Effects of Mixing of Recycled Newspaper and Rice Straw on Physical Properties of Packaging Trays (신문고지와 볏짚의 혼합이 포장 트레이의 물성에 미치는 효과)

  • Ahn, Byoung-Kuk
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.3 no.2
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    • pp.17-23
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    • 1996
  • Packaging trays were manufactured with recycled newspaper and rice straw to investigate the effect of mixing ratio of rice straw pulp on physical properties of the trays. The apparent density of the trays increased gradually with increasing mixing ratio of rice straw pulp and the bursting strength increased at the mixing ratio of above 40%. The results showed that the trays made from 100% rice straw pulp had the highest bursting strength and the trays with the mixing ratio of 20% and 100% had high compression strength. The air resistance of the trays decreased with increasing mixing ratio until 80%. As the mixing ratio of rice staw pulp in the trays increased, L value in color decreased and b value increased.

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손상된 파이프의 구조 안전성 평가

  • 박재학
    • Bulletin of the Korean Institute for Industrial Safety
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    • v.2 no.1
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    • pp.34-40
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    • 2002
  • 화학설비나 산업설비 또는 국가 기간 설비에서 파이프(pipe)는 중요한 위치를 차지하고 있으며 파이프의 파열은 그대로 대형 사고나 설비 가동의 중단으로 연결되는 경우가 많다. 따라서 파이프의 구조건전성을 유지하는 것은 안전의 확보와 생산 설비의 효율적 운용을 위하여 긴요하다. 파이프 재료 내부에는 재료 제작 시, 또는 파이프 제작 시 발생된 결함이나 사용 중 부식이나 피로 등의 영향으로 생성된 결함이 존재한다. 이러한 결함은 파이프의 강도를 낮추게 되고, 파이프의 잔류강도가 사용압력보다 낮아지게 되면 파이프가 파열하게 된다. 따라서 본 글에서는 파이프에 균열이 존재하거나 손상된 경우의 구조안전성 평가를 위하여 필요한 해석방법에 대하여 살펴본다.(중략)

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A Study on the Vented Gas Explosion Characteristics of Indoor Leakage of the LPG (실내 LPG 누출시 폭발특성에 관한 연구)

  • Oh Kyu-hyung;Kim Hong;Kim Sang-sub;Jo Yoong-do;Jo Jee-whan;Oh Shin-kyu
    • Journal of the Korean Institute of Gas
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    • v.3 no.3 s.8
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    • pp.51-57
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    • 1999
  • A study on the vented gas explosion characteristics were carried out with the liquified petroleum gas(LPG) which is used in domestics and industries fuel. To evaluate a damage by gas explosion and to predict a explosion hazards, a series of experiment have been performed in the regular hexahedron vessel of 270${\iota}$. A side of the vessel was made to setting a polyester diaphragm which was ruptured by explosion to simulate an accidental explosion which ruptured the window by explosion. Experimental parameters were LPG concentration, ignition position, venting area, a strength of diaphragm which was ruptured and distances from venting, Experimental results showed that vented gas explosion pressure was more affected by the diaphragm strength than the gas concentration, and the vented gas explosion pressure and blast wave pressure was increased with decreasing the venting area and increasing the strength of diaphragm. In this research we can find that a damage by vented explosion at the outside can be larger than the inside by blast wave pressure near the venting.

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