유리섬유강화 열가소성 복합재료의 성형조건이 파괴인성에 미치는 영향에 관한 연구

양철곤,이덕래,이재호 한국섬유공학회 1999 한국섬유공학회지 Vol.36 No.8

Although thermoplastic composites have many attractive physical properties including toughness and high strength, they have not been used widely due to poor processability. In this study, the unidirectional composites were fabricated under different molding pressures and holding time using parallel yarn which consists of 30, 40 and 50 volume percent of glass fiber. The mechanical properties of PET/GF composite were investigated by ILSS and DCB (double cantilever beam) methods. The relationship between molding conditions and mechanical properties were discussed. Moreover, observation of fracture surfaces using SEM clarified the influence of molding conditions on fracture behavior. As a result, it was also observed that severe increase in molding pressure caused extrusion of resin and increase in void fraction, which in turn to decrease in fracture toughness.

異形斷面 纖維의 굽힘剛性 測定方法

楊澈坤 成均館大學校 科學技術硏究所 1983 論文集 Vol.34 No.2

This study discussed the mothod for measuring the bending rigidity of fine fibres which had noncircular cross-section by the cantilever method. To obtain the relation between deflection and force for a single fibre, the apparatus consisted of a U-gauge, a differential linear transformer and a recorder was used. As the result of comparing the bending rigidity G, measured by the cantilever method with the bending rigidity EI, measured by the tensile testing method, the values of G were lower than those of EI. It was supposed that the adoption of the cantilever method for the measurement of bending rigidity was more recommendable than that of tensile testing method based on the simplicity of experiments and experimental errors.

1978學年度 新入生 心理特性

楊澈坤,金言柱,權純明 충남대학교 1979 學生生活硏究 Vol.6 No.-

接着布의 굽힘剛性에 관한 硏究

楊澈坤,權普淵 成均館大學校 科學技術硏究所 1985 論文集 Vol.36 No.2

In order to predict the bending rigidity of composite fabric, we derived the equations calculating bendin rigidity, when the bending rigidity of face fabric and interlining base cloth, their thickness, the size of dot and the density of dot were given. And then we compared the equations with the experiment. As the important structural parameters we considered three shapes of dot, i.e., circular, square and triangular shape, respectively. The results of this study are as following; 1. When the shape of dot is circular, square and triangular, the equation predicting bending rigidity of composite fabric matches well with the experimental value in certain range. 2. In the case of same size and density of dot, the bending rigidities of composite fabric are almost the same without regard to any shape of dot. 3. With the same total area of dots in unit area, the bonding rigidities of composite fabric are almost the same without regard to the number of dot.

羊毛 Crimp의 橫壓縮擧動에 關한 硏究

楊澈坤,裵基瑞 충남대학교 공업기술개발연구소 1976 工業技術開發硏究所論文集 Vol.3 No.2

Concerning with the mechanics of wool crimps deformation, the tensile and torsional behavior along the longitudinal axis have been studied by many authors. However, published papers reporting the lateral behavior are extremely limited in number. In the present study, attempts have been made to investigate the lateral compressive behavior of wool crimps (Polwarth 65'^s ram). The main results are; 1) For the crimps of sine curve form, the variation of E.C.D. may be obtained by var.E.C.D.=(FR^3)/(4EI)(π-8/π) 2) For the crimps of helix form, the lateral compressive force F per pitch is obtained by the sum F_1+F_2, where F_1 is the force due to the bending deformation and F_2 the force associated with the torsional deformation.

'77학년도 신입생의 知能檢査 結果 分析

楊澈坤,金言柱 충남대학교 1978 學生生活硏究 Vol.5 No.-

1,460명을 대상으로 실시된 '77학년도 신입생의 IQ 결과는 다음과 같았다. 신입생 전체의 IQ 평균은 105이고 표준편차는 9.8이다. 의예과 신입생의 IQ 평균치(118)가 가장 높았고, IQ 120이상 학생은 전체의 11%이고 IQ 80이하가 10%이었다. 표준화집단의 IQ와 비교해 볼 때, 신입생 전체의 47%가 上(75~100 percentile)에, 29%가 中上(50~74 percentile)에, 20%가 中下(25~49 percentile)에 4%가 下(0~24 percentile)에 속해 있다. 제시된 提言은 知的 能力에 따른 敎授法의 多樣化를 통한 敎授의 個別化方法이었다.

新入生 環境調査

楊澈坤,金言柱 충남대학교 1978 學生生活硏究 Vol.5 No.-

1977학년도 신입생 1,341명(남 1,153, 여 188)의 환경조사 결과를 보면, 신입생의 72%가 18~19세이고, 44%가 大田高, 忠南高, 普文高 및 大田女高 출신이며 性比는 男學生이 85%이다. 신입생의 57%가 宗敎를 갖고 있지 않으며, 최대 관심사는 학업·취업·건강문제이고, 문제발생시 상담자는 친구와 부모가 절대적인 資源人事이며, 兵役問題는 R.O.T.C. 지망생이 30%이다. 신입생의 42%가 가정에서 너무 통제가 심한 것을 불만의 원인으로 생각하며, 30%가 아버지 및 손윗 형제와 갈등을 빚고 있으며, 학비는 86%가 가정에 의존하고, 보호자 직업은 농업(30%), 상업(18%), 공무원(22%)이 많고, 경제수준은 中流이고, 부모의 학력수준은 「국졸」이 각각 32%, 57%로 가장 많다. 대학 입학동기는 학문(35%), 인격도야(28%)순이며, 전공선택은 적성(56%)과 취업조건(13%)을 고려하였으며, 희망 전공계열이나 학과에 입학한 사람이 63%이고, 轉科 희망자가 29%이다. 훌륭한 대학 要件으로 훌륭한 교수가 있고(15%), 취업지도가 잘 되고(15%), 우수학생이 많은 것(15%)을 들고 있다. 신입생의 45%가 인간성을 중심으로 同性 및 異性친구를 선택하며, 참여하고 싶은 단체활동은 우정 및 교양단체(25%), 학술 및 봉사단체(14%)이다. 제시된 논의와 결론은, 大田高·忠南高·普文高·大田女高等이 홍보의 중심 표적이 되어야 하며, 여학생을 위한 施設보완, 객지생활하는 학생의 생활지도 마련, 학생관심사 중심의 행사준비, 전공에의 適應지도 및 친구와 이성교제를 위한 교양강좌 개설 등이었다.

羊毛 Crimp의 引張擧動에 關한 硏究

楊澈坤 충남대학교 공업기술개발연구소 1975 工業技術開發硏究所論文集 Vol.2 No.2

Geometrical expression of wool crimps and load-deflection relation of crimps under tension were investigated theoretically with E. C. D. as a parameter. Experimental verification was made with samples of Polwarth 65's ram wool grown in Korea, and the results are as follows: 1. Geometry of irregular wool crimps can be expressed in terms of curvature, torsion and end view. 2. Below the elastic limit, load-deflection relation of crimps under tension was established. 3. E. C. D. in the elastic range with a parameter, load, can be found from E. C. D. = 4 ε√(EI/F_x) and with a parameter, wave length, can be expressed as ; E. C. D. = (ελ)/(2E(ε, π/2)-F(ε,π/2)) 4. Elastic limit of the wool crimp used for this experiment is about 7mg/d.

工業系 實科敎師 再敎育 改善을 위한 調査硏究

楊澈坤,李載元,金言柱 충남대학교 1977 工業技術開發硏究所論文集 Vol.4 No.2

This study aims to evaluate the in-service technical teacher training program which was conducted by the Industrial Education College Staff C.N.U. for six weeks from July 18th to August 27th in 1977. The pre-designed questionars were distributed to the 471 participated technical high school teachers and responded data collected from the 467 teachers out of 471 ones were analysed and studied. It is desirable to consider the following founds of this study in the future in-service teacher training programs which are expected to conduct every year by the Industrial Education College Staff. The founds of this study are: a. The majority of the participated teachers responded that they have not only improved their professional knowledges and skills but also facilitated their professional responsibilities as the technical teachers. b. The levels of the lectures presented by the Architectural and Electronic faculties were more or less exceeded participants' acceptances. c. The contents of the programs conducted by the chemical textile and metallurgical faculties were more or less not closely related to the Technical High School curricula offered by the participants. d. The program should be emphasised more Lab./Shop practices than class lectures in order to improve their skill competencies. e. The field trip/visiting industries should be guided more often than it has been done. f. The amount of allowance for participants payed from each local board of education should be reached to the government established standard.

1976學年度 新入生 選拔考査 結果分析

楊澈坤,崔鍾碩,李東洙 충남대학교 1976 學生生活硏究 Vol.4 No.-

The synthesis and analysis for the result of the entrance examination of Chungnam University in 1976 are as follows : 1. The difference between proportion of standard contribution and proportion of practical contribution in written tests was 11.5% in Natural Science division, 5.5% in Humanity and Social divisions, and it was 10% proportion of added contribution, as the proportion of contribution showed 52% practically. As the standard deviation was low for the average points in certain subjects, the distinctive effect was very poor. As the difference of mean between the subjects has significance, it is necessary for us to make porportion of practical contribution get near to the proportion of standard contribution and to promote the distinctive effect by considering the difficult level promote when giving an examination. 2. The fact that there was an extremely low correlation coefficient among the same subjects in prelimanary and entrance examination in all the subjects except English (including foreign languages) in Humanity and Social division and in mathematics and science in Natural Science division showed that there were many absurdities in uniformity in giving tests, guidance for writing answers and guidance for the entrance examination for applicants. It is necessary that Ministry of Education and university authorities should take into consideration to the equalization of high schools with the organic study on the entrance examination, special guidance for the subjective test and the special guidance for the many fields of study. 3. As English Ⅱ, German, Japanese, Chinese, and Spanish are optiomal subjects, there appears a significant difference between average proportions of points owing to complex factors. Since this problem occurs every year, it seems rational that standard score should be adopted. 4. Though the standard proportion of oral test in getting points is 2.5%, there apears rather high level of practical contribution. As the standard variation is weak indistinctive effect, 2.4% in Natural Science division, 2.5% in Humanity and Social divisions, and has not correlation with other subjects, but has independence, it is hopeful to add oral test to the total points of entrance examination.