유전자알고리즘에 의한 Wire의 최적 Cutting 프로그램 개발과 동적변형률 특성에 관한연구 = Development of Wire Cutting Program and Characteristics of Dynamic Strain Rate using Genetic Algorithm

다국어 초록 (Multilingual Abstract)

Recently, the concern of the safety side of a vehicle increases. The use of the wire for the safety belt linked directly with the safety is increased. In a general way, the initial sawing process is required for the process of the wire. However, as to current, the disconnect mode by the torch heating and cutting blade is used. It has the disadvantage called many failure rate and semi-automation
The dissimilar method is required. In this paper, by using the wire of 7☓19☓4.3 used in the safety belt, the tensile strength evaluation according to the strain rate was evaluated. Moreover, studied for the wire cutting using induction heating system.
A model between the output and many input variables were found in the wire cutting and presented of analytic and numerical methods by using the result data. The process of cutting the wire by using the induction heating system thinks as the national first field of investigation.
The genetic algorithm, that is the probable method, was used in order to research the effective optimal design In order that the objective function in which it is suitable for the process was found, by using a parameter including a current, a pressure, frequency. The cutting experiment was implemented By using a specimen, the diameter change rate, the length change, and the calorific value were analyzed. optimum was made data into. And according to the change of a speed, it confirmed whether the mechanical property of the wire showed any change or not. experiment was enforced. And the breaking load, the displacement, and data of the yield load were drawn with result data.
It confirmed that any reaction occurred due to the change of a speed by using the mean value of each data. This research data provided the new parameter that it is the cut of the wire. And it defined the characteristic of the mechanical property of the wire according to the speed of the strain rate.
The test results are summarized as follow.
1. The cut Trim increased as the intensity as to a frequency, increased among the conditional variable of the induction heating sawing process. And the rate of change of a diameter reduced. However, as to a current and pressure, the cut Trim reduced as the intensity increased. The rate of change of a diameter increased.
2. Experimental data were analyzed and a result was gotten.
And by using the genetic algorithm, the wire cutting variable confirmation program called the Wire Pro was developed.
3. As a result of practicing the Wire Pro and finding the cutting condition according to the cut variable, it showed that the pressure of 4.0kgf/mm2, the current of 25(A), and the frequency of 20(Hz) were the cutting condition of an optimum.
4. According to the strain rate 0.1 ~ 0.2sec-1 change, as a result of implementing the Breaking Test, data could analyze with a prediction whether the same tendency as data in which it elicits in the enervation modulus related Loading Rate Sensitivity in Tensile Strength Characteristics type and data in which it elicits in the Campbell & Cooper dynamic tensile strength type was shown and the mechanical property of the wire maintained a level with a speed or not.
5. By using FEM, the reliability of Breaking Test result data of the wire according to the strain rate was secured. And we presented to be prediction data and the efficient method of study in the mechanical characteristic study of the it is different after a flavor wire of the size in which.
It confirmed to draw optimal cutting qualifying data of the wire through the experimental result like an abnormal and could efficiently utilize the cutting condition about a parameter. It could be predicted with a confirmation whether the mechanical property of the wire had any change through the Breaking Test of the wire according to a speed or not.
Especially, in predicting the of being different after a verification and flavor about the Breaking Test experiment characteristic toward the wire of the size, the interpretation through FEM presented to be the effective method.

목차 (Table of Contents)

• 목차 ⅰ
• Abstract ⅲ
• List of tables ⅶ
• List of figures ⅷ
• 제1장 서론 1
• 1-1. 연구배경 1
• 1-2. 연구동향 2
• 1-2-1. 역사적 배경 2
• 1-2-2. 국내 연구동향 3
• 1-2-3. 국외 연구동향 5
• 1-3. 연구목적 및 내용 6
• 제2장. 유전자알고리즘 8
• 2-1. 유전자알고리즘 기본개념 8
• 2-2. 유전자알고리즘 동작 및 특징 9
• 2-3. 유전자알고리즘 구성요소 10
• 2-3-1. 개체 표현방법 10
• 2-3-2. 유전 연산자 11
• 2-3-3. 적합도 함수 12
• 2-3-4. 선택 메커니즘 12
• 2-3-5. 알고리즘 제어 파라미터 13
• 제3장. 변형률속도 17
• 3-1. 유도가열 Cutting Machine 원리 17
• 3-2. Wire Cutting 실험 및 평가 21
• 3-2-1. 와이어 절단면 평가 28
• 3-2-2. 유전자알고리즘 목적함수 및 절단 조건 31
• 3-3. 변형률속도에 의한 파단특성 평가 35
• 3-3-1. Campbell & Cooper 이론식 35
• 3-3-2. 하중속도 민감성 36
• 3-4. FEM 해석 37
• 3-4-1. 재료 물성치 37
• 3-4-2. 모델링 38
• 제4장. Wire Cutting 프로그램 41
• 4-1. 실험조건에 따른 와이어의 절단 실험 41
• 4-2. 유전자알고리즘을 이용한 최적조건 도출 50
• 4-3. Wire Pro 프로그램 58
• 4-4. 변형률 속도에 따른 와이어 파단실험 결과 62
• 4-5. FEM 해석결과 67
• 제5장. 결론 73
• 참고문헌 75