http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
계장화 샤르피충격시험기를 이용한 고무보강 폴리머재료의 파괴인자 결정에 관한연구
박명균,최영식,박세만,양진승,Park, Myeong-Gyun,Choe, Yeong-Sik,Park, Se-Man,Yang, Jin-Seung 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.8
The Charpy and Izod impact tests are the most prevalent techniques used to characterize the effects of high impulse loads on ploymeric materials. An analysis method for rubber toughened PVC is suggested to evaluate critical dynamic strain energy release rates(G$\_$c/) from the Charpy impact energy measurements. An instrumented Charpy impact tester was used to extract ancillary information concerning fracture parameters in addition to total fracture energies and maximum critical loads. The dynamic stress intensity factor Kid was computed for varying amounts of rubber contents from the obtained maximum critical loads and also toughening effects were investigated as well.
A Residual Stress Evaluation in Laser Welded Lap Joint with Hole Drilling Method
박명균,이수진,Behzad Ahmed Zai,Hassan Mehboob,Rashid Ali Sindhu 한국정밀공학회 2009 International Journal of Precision Engineering and Vol.10 No.5
Residual stresses deteriorate strength of materials affecting the quality of industrial products. A removal or reduction of the residual stresses is an essential procedure in successful engineering component development. Effective and convenient methods are necessary for detection and evaluation of residual stresses. In this paper Hole Drilling Method is chosen for identification and a quantitative determination of the residual stresses in specimens of two groups under different laser welding speed conditions, 4.1m/min and 5.1m/min. The lap joints welded with STS 301L sheet of two different speeds were investigated along the welding line at two locations, the middle and the end location in the heat affected zone (HAZ). The identification of HAZ is carried out by taking hardness values from weld centerline to the raw material. Based on the experimental results and analysis, it is found that higher welding speed reduces the residual stresses. Also, the end location is found to be higher residual stress area compared with middle location due to the convective boundary condition. The residual stresses decrease as the depth increases from the top surface due to the lower heat input to depth increments.