R 곡선상의 안정균열개시점 결정을 위한 수정옵셋방법

안광주,최재강,박준수 한국산업안전학회 1999 한국안전학회지 Vol.14 No.3

This paper were performed to evaluate the elastic-plastic fracture toughness J_(IC) by the unloading compliance method for 1/2 CT specimen of A5083-H112 aluminum alloy. A modified offset method for negative crack growth effect is presented and compared with Voss offset method. We found that the modified offset method presented can be used efficiently for a determination of the stable crack onset. The J_(IC) by Voss offset method can be overestimated, but the suggested offset method showed a high reliability within 5% of tolerence from the results by the multi-specimen method.

제하컴플라이언스법에 의한 A5083 알루미늄합금의 탄소성파괴인성 평가

안광주,최재강 東義大學校 産業技術開發硏究所 1997 産業技術硏究誌 Vol.11 No.-

A 5083-H112 aluminum alloy in AI-Mg group is an important material and used for manufacturing a LNG tank which transports the liquified natural gas. In this investigation, the elastic- plastic fracture toughness of this material is evaluated by an unloading compliance method according to the ASTM E813-89 method on the smooth and side groove ?CT specimens. The effect of heat treatment (annealing and quenching) and welding is studied on the elastic-plastic fracture toughness. A modified offset method is proposed for the negative crack due to the negative crack effect.

構造用鋼의 J-△a 曲線評價

안광주,박일주,최재강,원종식 東義大學校産業技術開發硏究所 1993 産業技術硏究誌 Vol.7 No.-

IIn this paper, the elastic-plastic fracture toughness J₁c of a structural steel SS41 was discussed. The main efforts were focussed on the comparison of the J₁c values determined by the ASTM R-curve method, the JSME R-curve method, the ASTM partial unloading compliance method, and impact test method. In parallel with this efforts, however, measurements were also made simulaneously to detect the relationship between △aASTM,△aJSME and △a21. The results obtained are as follows ; 1) A relation between △aASTM,△aJSME and △a21 for each specimen shows that the following linear equation stands △aASTM=1.0533 △a21 △aJSME=1.4478 △a21 and it is ascertained that the △aASTM is a simple reliable method in the evaluation of crack extension. 2) In the ASTM E 813-81 R-curve method, the valid ?? values are obtained as JQ=165.18 kN/m, while on the other hand, in the ASTM E 813-88 method the JQ values are not obtained because there is no J-△a point between a line parallel to the blunting line at an offset of 1.0mm and the 1.5mm exclusion line. Hence, the ASTM E 813-81 R-curve method is more desirable than the ASTM E 813-88 R-curve method. 3) In the partial unloading compliance method, the JQ values obtained by E 813-81 and E 813-88 are more excessively estimated by 9.9% and 24.3% than those by the JSME R-curve method. On the other hand the J₁c values by the modified E 813-88 method which proposed by Carlson are fairly close to those by the JSME R-curve method. So the modified E 813-88 method is desirable to estimate the J₁c value of structural steel. 4) The J₁c values by the impact test method has 13% deviation from those by the ASTM E 813-81 R-curve method in SS41 specimens. However the impact test method also can be used as a reliable method in case the correction factor adopted.

除荷콤프라이언스法에 의한 低强度 構造用鋼 SB41의 Jic評價

洪永杓,安光珠 東義大學校産業技術開發硏究所 1987 産業技術硏究誌 Vol.1 No.-

A ?? criterion and its test method were developed by Begley, Landes and ASTM Task Group E24. Their test method was adopted into ASTM E 813-81. In ASTM E813-81 attention is directed mainly to processes of ductile tearing. Blunting line is assumed ??△a and the R curve is determined by the multiple specimen technique or the single specimen unloading compliance technique. In the ASTM recommended procedure, the ?? value at the onset of crack growth is given by the intersection point between a best straight line fit of the data of J versus △a and an assumed blunting line. In this paper, the elastic-plastic fracture toughness ?? of a structural steel SB 41 and submerged arc welded SB 41 weldment which have the properties of low strength and high ductility was discussed. The main efforts were focussed on the comparison of the ?? values determined by the ASTM R curve method, ASTM partial unloading compliance method and JSME R curve method. In the partial unloading compliance method, a power law equation was found to give a better fit to the J-△ a data in high ductility meterials. And an alternative to the ASTM E813-81 procedure was suggested, based on the experimentally modified blunting line.

이온窒化處理한 構造用鋼 SS14의 彈塑性壤靭性 評價

안광주,이상봉,최재강 東義大學校 産業技術開發硏究所 1996 産業技術硏究誌 Vol.10 No.-

In this study the elastic-plastic fracture toughness J???? for ion-nirided structural steel SS41 has been estimated with the single specimen unloading compliance techniques and focused on the J???? values of CT specimens through a comparison of the normalized with the ion-nitrided. The results throughout the evaluation of fracture toughness J???? were obtained as follows ; 1) In the ASTM E 813-92 R-curve method. J??? value for the nomalized CT specimen was evaluated as J???=440kN/m but its value is invalid for the J???? in respect to the effective conditional requirements. 2) In the ASTM E 813-92 R-curve method. J??? values for the ion-nitrided CT specimen were evaluated as 275 kN/m and 280 kN/m, respectively and it values is valid for the elastic plastic fracture toughness J????. 3) J???? evaluation for high ductile materials had better use of the measured blunting line rather than the assumed blunting line in the ASTM E 813-92. 4) In the cases of high ductile materials. The best fitting curve for the R-curve is able to give as y=cx??? and y=a+bx???, and they can apply efficiently to evaluate J????.

動的荷重下의 破壞靭性에 대한 簡便評價

안광주,허관도,이천석 東義大學校産業技術開發硏究所 1990 産業技術硏究誌 Vol.4 No.-

The Charpy impact test is rapidly being upgraded to include instrumentation for revealing the load history of the specimen while it is being fractured in three-point bending. The fracture toughness, ??, was measured in structural steel SS41B-D using precracked Charpy specimens and an instrumented impact testing machine. Values of ?? were determined as a function of yield strength and correlations were established between ?? and the energy to initiate fracture. On the basis of the experimental results observed in this investigation, following important conclusions can be made; 1. The instrumented precracked Charpy test can be effectively used to determine relative fracture toughness. Under proper condition the instrumented precracked Charpy test can be used to determine planestrain fracture toughness values and the dynamic fracture toughness, ??, is related to both the energy to initiate fracture and total energy of fracture. 2. The Rolfe-Novak relationship, ??, appears to give a reasonable and conservative estimate of ?? based on CVN data. 3. ?? should be estimated using equation, ?? based on CVN data.

構造用鋼 SS41材의 衝擊荷重에 의한 破壞擧動

王志成,安光珠 東義大學校産業技術開發硏究所 1989 産業技術硏究誌 Vol.3 No.-

The effect of impact velocity on dynamic fracture toughness was evaluated by use of the instrumented Charpy impact test with PCVN specimens and the effect of notch radius on impact value by the standard Charpy impact test with CUN specimens. The tests were made at impact velocities ranging from 0.73m/s to 5.41m/s. The dynamic fracture toughness, ?? and ?? marked as the deviation of 4-5% as compared with the static fracture toughness ?? obtained with CT specimens. The instrumented precracked Charpy test is shown to be a convenient method of determining relative fracture toughness. The stable crack growth does depend rather strongly on the J value in case of high impact velocities and less strongly on the J value in case of low impact velocities.

초현실주의 스타일의 광고표현 양식

안인선,명광주 한국기초조형학회 2002 기초조형학연구 Vol.3 No.2

현대사회 속의 광고는 없어서는 안될 매우 중요한 요서로 자리잡고 있다. 사람과 사람, 사회와 사회, 회사와 회사들간의 커뮤니케이션하는 틀로써 매우 중요한 역할을 한다. 우리 사회는 지난 20세기말부터 21세기 오늘에 이르기까지 중대한 변화들이 있었다. 이러한 사회의 다양한 요소들의 변화는 광고의 변화에도 영향을 주어 광고양의 팽창, 광고자극의 일반화라는 문제점이 야기되었다. 이런 상황에서 광고는 이전의 장식적이고 기능만을 추구하는 광고보다는 어떻게 해야 소비자들을 어필할 수 있는가에 대한 것에 초점을 맞추었다. 광고의 표현들에 여러 가지 유형이 있었지만, 초현실주의 기법의 광고 표현들이 크게 증가하여 나타난 것도 두드러진 변화의 양상이다. 이에 본 논문은 이와 같은 광고표현에 있어서의 초현실주의 양식 광고들이 환경변화와 어떤 관계를 갖고 있고 소비자에게 얼마만큼 수용되고 있는지에 대해서 전반적인 검토가 필요하다고 판단하여, 이에 대한 이론적인 분석접근과 실제의 초현실주의 양식 광고들의 사례에 대한 소비자 선호도조사를 실시하여 효과를 파악하는데 초점을 맞추고 있다. 본 연구는 이 시대 주요 광고표현양식의 하나인 초현실주의 광고양식에 대한 연구를 심화함으로써 우리나라 광고표현에 기여 할 것을 기대한다. Our modern society is getting more complicated than ever before because of information by internet and other media. The quantity of advertisements reflect on society has been expanded due to media's development, so consumer is getting used to them. Therefore, the differentiated advertisement from the others is the most considerable idea to satisfy the consumer. It will be desirable for us to apply advertisements to Surrealism mode as a creative strategy to realize the differentiate.

SB41 강의 평골 및 측면홈 CT시험편의 $J_{IC}$평가

오세욱,안광주,윤영재 대한기계학회 1986 대한기계학회논문집 Vol.10 No.4

본 연구에서는 저강도.고연성재인 일반구조용압연강 SB41의 평골 CT 시험편과 양측면홈이 있는 CT시험편을 사용하여 ASTM R유선법, JSME R유선법,SZW법, 초음파법 및 전입차법에 따라 J$_{IC}$를 종합적으로 평가하였다. 복수시험편법인 ASTM 및 JSME 및 JSME R유선법을 상호 비교고찰하므로써 저강도.고연성재에 대한 파환인성평가 의 적용한계를 명확히 하였으며 단일시험편법인 초음파 및 전입차시험법은 효율적이고 간편한 J$_{IC}$평가법임을 확인하였다.

構造用鋼의 熱處理溫度에 따른 衝擊特性에 관한 硏究

吳世旭,安光珠 동아대학교 공과대학 부설 한국자원개발연구소 1983 硏究報告 Vol.7 No.1

It is not enough to determine the impact property by the absorbed impact energy only, so the measurement of impact load has been urged. In impact test the charpy specimen with U type notch were used to determine the impact properties. The specimens were tempered from 100℃ to 800℃ after quenching. Experiments were carried out for such characteristics as impact load, impact value, loading, period, deflection and reduction rate of loading speed. The experimental results are summarized as follows; 1. By comparing with tempering temperature at maximum load between impact and static, tempering temperature of impact specimen is higher than those of the static specimen. 2. Static ratio(γ) between impact and static loading are; γ=1.17~1.60 for spring steel. γ=1.02~1.23 for SM20C steel. 3. The transition tempering temperature in impact value and velocity reduction rate is 300℃.