전략계획 특성에 따른 지방자치단체장의 바람직한 역할

안태환(安泰煥) 한국지방자치학회 2002 韓國地方自治學會報 Vol.14 No.4

(주) 코오롱 기술연구소

안태환 한국의류산업학회 1999 한국의류산업학회지 Vol.1 No.4

2단 2중 반복하중하에서 재료의 피로거동

安台煥 忠州大學校 1999 한국교통대학교 논문집 Vol.34 No.1

A study was made to determine the effects of fatigue strength and crack orientation to the axis on the fatigue crack growth rate of mild steel. Four types of bar specimens, the bar type specimens with two different types and the center notched bar specimens with two different types. Two types was heat treatment and ungeat treatment were used. Strain and stroke distributions in spccimens were examined by means of the dynastrain gage. In the case of under constant repeat axile load with 2nd step load and cycles. Therefore, if the test results of bar spccimens were used to evaluate the life of a unnotched structure, it is on the unsafe side.

鋼材의 低싸이클 疲勞에 關한 硏究

安台煥 忠州大學校 1998 한국교통대학교 논문집 Vol.33 No.1

A Method for prediction of necked-out fatigue fracture under low cycle loading was proposed, in case of the necked-out type fatigue fracture. It may be assumed that fatigue life has been used up when necking began. In such a case, when accumulated permanent strain εm, amounts to critical value εus the fatigue failure occurs, and the critical value is nearly equal to the general elongation of material εu0. Then a relation between strain and number of cycles is expressed approximately as follows ; Δεm Nus=εus-ε0=εu0-ε0 where Δεm is a cyclic creep rata at the stationary stage which occupid major part of whole fatigue life, Nus is Number of cycles to the fatigue failure and ε0 is a permanent strain at the first cycle. The cyclic creep rata Δεm is corrected to nominal stress σmax, and stress ratio R, and the following relation is assumed. (σB-σmax)σY=(ΣAlRi)Δεmmβ Constants Al, and exponent β, in the above equation are able to be obtained from statical test results. In order to prove the validity of these equations, mild steel specimens were tested under constant repeated axile loads with several stress ratio, and the results were compared with the values calculated by the equations, and fairly good agreements between them were obtained.

변동하중하의 피로균열 전파속도 추정에 관한연구

安台煥 충주대학교 1994 한국교통대학교 논문집 Vol.29 No.1

Under variable amplitude loading conditions, load interaction (retardation or acceleration of fatigue crack growth) occurs every cycle. Because fatigue crack growth behavior varied depending on load time history. This paper would present the modeling of stress amplitude with storm loading applied to ships, and offshore structures. It will examine crack closure behavior which was done by monitoring the variation in load-strain relationship. By taking process mentioned above, fatigue crack growth rate, threshold stress, crack length, stress intensity factor, and ΔΚop were obtained during stress cycles of each type of storm of A(6m), B(7m), C(8m), D(9m), E(11m), and F(15m). It is believed that, using of the simulation of storm loads, could give good agreements with experimental results, and that this estimated method gives a good criterion for the safe navigation of vessels. It also inferred that the method could offer easy access to establish a fatigue design data for ship building and offshore structures.

地域社會의 發展과 地方自治

安泰煥 대구대학교 새마을 . 지역사회개발연구소 1990 地域社會開發論叢 Vol.12 No.-

The purpose of this paper is to examine the interrelationship between the changing factors of local urban community and major problems of it, and to suggest its development strategies. Since Korea society had experienced rapid industrialization and urbanization during last one gene-ration, local communities and cities were changed in most sectors. Thus most local cities showed several regional and urban problems, for example, : (1) high dependence on Seoul in most aspects, (2) unbalance among most urban sector, (3) urban shadow area, etc. So development strategies for local communities are suggested as follows : (1) propelling the high level of industrialization, (2) enforcing public administration based on socio-economic region, (3) inducing the balanced development in regional and class inequality, (4) preparing for open and international society, (5) propelling the decentralization based on the sound regionalism, etc. Based on these strategies, the local government, local assembly, its man, and residence which are considered as changing agents and actors, have been demanded the peculiar role and functions in accordance with the above strategies.

저사이클 피로특성에 관한 연구

安台煥 충주대 2000 한국교통대학교 논문집 Vol.35 No.1

A study was made to determine the effects of fatigue behavior and plastic energy to the axis on the low cycle of mild steel.Eleven types of stress amplitude under stress control mode.Strain and stroke distributions in specimens were examined by means of the dynastrain gage. In the case of under constant repeat axile stress with triangular wave low cycles Therefore, if the test results of bar specimens were used to evaluated the life of a unnotched structure, it is on the unsafe side.

大都市 周邊地域의 實態와 地域開發方向 - 大邱市와 達城群을 中心으로 -

安泰煥 韓國社會事業大學 地域社會開發硏究所 1989 地域社會開發論叢 Vol.11 No.-

The purpose of this paper was to examine the situation of metropolitan surrounding area and to suggest its development strategies. Since most large cities in Korea have been over-densed with rapid urbanization, urbanized area has been expanded and non-central activities have been sprawed into urban fringe or suburban area. Thus most metropolitan surrounding areas have appeared several regional problems and become urban shadow-area. This study analyzed the situation of Dalsung county, which is typical Taegu surrounding area and searched for its development strategies. Dalsung county showed several regional problems : (1) high dependence upon Taegu, (2) division of its spational organization, (3) no existence of regional center, etc. And most residents expressed their concerns about their county problems such as : (1) shortage of young adults and change agents, (2) lack of public investment and working place, (3) insufficient living conditions, etc. So most residents wanted to locate the plants, increase income, improve the quality of life, and reduce the several public regulations. Based on these analyses, the development strategies for surrounding area, particularly in Dalsung county, was suggested as follows : (1) cordinating of socio-economic area and its municipal districts, (2) setting the regional center and settlement system, (3) propelling the high level of industrilization, (4) establishing the technopolis network, and finally improving social infrastructure conditions.

Ti-6Al-4V 티타늄 합금의 미소 피로 크랙에 관한 연구

안태환 忠州大學校 2002 한국교통대학교 논문집 Vol.37 No.4

The purpose of this paper was to investingate the small crack growth rate and long fatigue crack growth behavior of Ti-6Al-4V

양단이 반원이고 평행으로 이어진 구멍의 應力集中에 關한 硏究

安台煥 忠州大學校 1984 한국교통대학교 논문집 Vol.17 No.2

When designing such structures and mechines, Various factors have tobe into consideration. One of these is the stress concentration around holes. Neuber derives stress concentration factors analytically for all types of notches loaded in uniform tension, pure bending, pure shear, and torsion. This paper deal with on the square hole with a semicircle in addition to parameter is diameter. As the conculsion of the research : 1) The increase of b/ρ is increasing the stress concentration factor. 2) The stress concentration factor is the indication a stright line of b/ρ=1.50-3.00