자동차 칵핏 모듈용 플라스틱 소재의 열화 동특성 평가

우창수(Chang Su Woo),박현성(Hyun Sung Park),조진호(Jin Ho Jo),김지훈(Ji Hoon Kim),최주호(Ju Ho Choi),김영국(Yeoung Kuk Kim) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.12

플라스틱 소재는 온도, 습도 및 자외선 등 다양한 환경의 영향으로 인해 기계적 물성변화가 심하기 때문에 체결부의 견고함이 느슨해지고 형태의 변형에 의해 부품간의 마찰 등을 유발하여 잡음이 발생하게 된다. 따라서, 본 논문에서는 자동차 칵핏 모듈에 사용되는 다양한 플라스틱 소재에 대해 온도변화에 따른 동 특성시험을 통해 유리전이온도, 저장탄성계수, 손실계수 등을 측정하여 상온 및 열화조건에 따른 물성변화를 파악하였다. 시험결과, 온도가 높을수록 저장탄성계수는 감소하고 손실계수는 증가하는 경향을 나타내었다. Engineering plastics are used in instrument panels, interior trim, and other vehicle applications, and the thermomechanical behaviors of plastic materials are strongly influenced by many environmental factors such as temperature, sunlight, and rain. As the material properties change, the mechanical parts create unexpected noise. In this study, the dynamic mechanical property changes of plastics used in automobiles are measured to investigate the temperature effects. Viscoelastic properties such as the glass transition temperature and storage modulus and loss factor under temperature and frequency sweeps were measured. The data were compared with the original ones before aging to analyze the behavior changes. It was found that as the temperature increased, the storage modulus decreased and the loss factor increased slightly.

자동차 칵핏 모듈용 플라스틱 소재의 열화 동특성 평가

우창수(Chang Su Woo),박현성(Hyun Sung Park),조진호(Jin Ho Jo),김지훈(Ji Hoon Kim),최주호(Ju Ho Choi),김영국(Yeoung Kuk Kim) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.5-2

플라스틱 소재는 온도, 습도 및 자외선 등 다양한 환경의 영향으로 인해 기계적 물성변화가 심하기 때문에 체결부의 견고함이 느슨해지고 형태의 변형에 의해 부품간의 마찰 등을 유발하여 잡음이 발생하게 된다. 따라서, 본 논문에서는 자동차 칵핏 모듈에 사용되는 다양한 플라스틱 소재에 대해 온도변화에 따른 동 특성시험을 통해 유리전이온도, 저장탄성계수, 손실계수 등을 측정하여 상온 및 열화조건에 따른 물성변화를 파악하였다. 시험결과, 온도가 높을수록 저장탄성계수는 감소하고 손실계수는 증가하는 경향을 나타내었다. Engineering plastics are used in instrument panels, interior trim, and other vehicle applications, and the thermo-mechanical behaviors of plastic materials are strongly influenced by many environmental factors such as temperature, sun light, and rain. As the properties change, the mechanical parts creating unexpected noise. In this paper, the dynamic mechanical property changes of plastics for automobiles are measured to investigate the temperature effects. Visco-elastic properties such as the glass transition temperature and storage modulus and loss factor under temperature and frequency sweeps were measured. The data were compared with the original ones before the aging to analyze the behavior changes. As results, the temperature was increased, the storage modulus was decreased on the other hand, loss factor is slightly increases.

고무류 기계부품 통합설계시스템 개발

우창수(Chang Su Woo),김완두(Wan Doo Kim),김영길(Young Gil Kim),신외기(Wae Gi Shin),이성훈(Seong Hoon Lee) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.8

고무부품의 신뢰성을 확보하기 위해서는 피로수명예측 및 평가기술 개발이 중요하다 하겠다. 최근에 고무부품에 대한 고성능, 고신뢰성을 위해 설계, 해석 및 평가기술이 요구되고 있으나, 지금까지는 경험과 시행착오적인 방법으로 개발되고 있는 실정이다. 따라서, 본 연구에서는 고무소재에 대해 배합조건, 기계적 특성, 열화 및 피로수명 등을 포함하는 고무소재 물성 데이터베이스를 구축하고, 고무부품의 특성해석 결과를 데이터베이스와 연계하여 고무부품의 피로해석 모델을 개발하였으며, 실제 피로시험 결과를 통하여 개발된 모델의 타당성을 검증하였다. Fatigue analysis and lifetime evaluation are very important in design procedure for assuring the safety and reliability of rubber components for mechanical systems. Till recently, the technology for the design, analysis, and evaluation of rubber products was required to manufacture rubber products with high quality, fidelity, and reliability. However, in the rubber-manufacturing companies in Korea, the processes of compound mixing, manufacturing of rubber products, and improvement of rubber properties are based on the trial-and-error method and experience. The objectives of this study are to establish methods for testing rubber materials, to develop a database of the properties of rubber materials, to evaluate the performance of rubber components, and to develop a system for predicting fatigue life. A method to predict fatigue-life of rubber components was proposed; in this method, the finite-element analysis and fatigue damage parameter as determined from a fatigue test are incorporated.

철도차량용 프라이머리 고무스프링 신뢰성 평가

우창수(Chang Su Woo),박현성(Hyun Sung Park),박동철(Dong Chul Park) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.4

철도차량용 방진고무스프링 특성시험 및 평가

우창수(Woo Chang Su),박동철(Park Dong Chul) 한국철도학회 2006 한국철도학회 학술발표대회논문집 Vol.- No.-

Rubber spring is used in primary suspension system for railway vehicle. This rubber spring has function which reduce vibration and noise, support the load carried in operation of rail vehicle. The non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by material tests which are uni-axial tension and bi-axial tension and heat-ageing test. Also, the behaviors of load-displacement of rubber spring are evaluated by using commercial FEA code. It is shown that the results by simulations are agreement with test result.

고무부품 피로수명예측 및 통합설계시스템 개발

우창수(Chang Su Woo),김완두(Wan Doo Kim) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.신뢰성 No.-

철도차량용 원추형 고무스프링 특성 및 피로수명 평가

우창수(Chang-Su Woo),박현성(Hyun-Sung Park) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.5

본 연구에서는 철도차량 1차 현가장치에 사용되는 원추형 고무스프링에 대해 유한요소해석과 특성시험을 수행하여 수직방향, 길이방향, 횡 방향의 강성을 예측하고 평가하였다. 또한, 설계 초기 단계에서 짧은 기간에 고무부품의 피로수명을 예측할 수 있는 방법을 개발하여 원추형 고무스프링에 대한 피로수명을 평가한 결과, 실제 피로시험을 통해 얻어진 피로수명과 예측수명이 비교적 정확하게 예측됨을 확인하였다. Conical rubber springs are used in primary suspensions for railway vehicle. Conical rubber spring have function which reduce vibration and noise, support load carried in operation of railway vehicle. Prediction and evaluation of characteristics and fatigue lifetime are very important in design procedure to assure the safety and reliability of the rubber spring. The computer simulation using the nonlinear finite element analysis program executed to predict and evaluate the load and displacement for the conical rubber spring. The non-linear properties of rubber which are described as strain energy functions are important parameters. Also, fatigue lifetime prediction methodology of vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter of maximum Green-Lagrange strains appearing at the critical location determined from fatigue test. Predicted useful lifetime of the conical rubber spring showed a fairly good agreement with the experimental fatigue lifetime.

냉장고 압축기용 고무마운트 수명예측에 관한 연구

우창수(Chang Su Woo),박현성(Hyun Sung Park) 한국신뢰성학회 2006 신뢰성응용연구 Vol.6 No.2

고무-점토 나노복합체 물성 및 피로내구성 평가

우창수(Chang Su Woo),박현성(Hyun Sung Park),조득환(Deughwan Joe),전영식(Youngsig Jun) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.10

실리게이트의 층간에 나노충진제를 삽입하여 합성한 고무-점토 나노복합체에 대해 70?100℃ 의 고온상태에서 정적 및 동적시험을 수행하여 기존 고무소재보다 기계적 물성이 우수함을 확인하였다. 또한, 본 연구에서는 부품의 취약부위에서 발생하는 최대 그린-라그랑지 변형률을 피로손상변수로 하여 설계 초기단계에서도 짧은 기간에 고무부품의 피로수명을 예측할 수 있는 방법을 개발하여 피로내구성을 평가한 결과, 실제 엔진마운트에 대한 피로시험을 통해 얻어진 피로수명과 예측수명이 비교적 정확하게 예측됨을 확인하였다. Nanocomposites were prepared through the compounding of rubber and clay. Measurements of the static and dynamic mechanical properties of different compositions over a temperature range 70?100℃ showed that the mechanical properties of these rubber/clay nanocomposites are superior to those of existing rubber materials. In this study, by using the parameter of the maximum Green?agrange strain appearing at certain locations, the relationship between fatigue life and maximum Green?agrange strain, and the correlations between test-piece tests and bench tests of actual rubber components are proved. In order to predict the fatigue life of rubber components at the design stage, a simple procedure of life prediction is suggested. The predicted fatigue lives of the rubber engine mounts agree fairly well with the fatigue lives determined experimentally.

철도차량 1차 현가장치용 고무스프링 사용수명 예측모델 개발

우창수(Chang Su. Woo),박현성(Hyun Sung. Park) 한국도시철도학회 2019 한국도시철도학회논문집 Vol.7 No.1

Since rubber parts used in railway vehicles play an important role in driving stability, noise and vibration reduction of vehicles, useful lifetime prediction and evaluation of rubber components are very important for securing the safety and reliability for railway vehicles. In this study, we have developed a model to predict the useful lifetime of rubber springs used in the primary suspension system for railway vehicles. The predicted useful lifetime of rubber spring was confirmed to be in good agreement with the fatigue life obtained through the actual test. The validity of the useful lifetime prediction method will contribute greatly to the evaluation of lifetime for rubber components and the improvement of technology which have been difficult to secure reliability.