Waseda University · 공학
아쓰시 호소 교수의 연구실은 고강도 복합재료, 특히 탄소섬유 강화 플라스틱(CFRP)과 스테인리스 스틸의 피로 거동 및 균열 복원 기술에 중점을 두고 있습니다. 고주기 및 매우 높은 주기 피로 영역에서의 균열 형상, 전파 메커니즘, 그리고 전기맥박을 이용한 균열 치유 기술을 실험적·정량적으로 분석하고 있습니다. 특히 초음파 피로 시험을 활용한 가속화된 피로 평가 및 디지털 영상 코로네이션을 통한 응력 집중도 분석이 핵심 기술적 특징입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
A technique to heal a fatigue crack in austenitic stainless steel SUS316 by applying a controlled, high-density pulsed current was developed. A surface-activated pre-coating (SAPC), which eliminates the oxide layer and coats a Ni film on the crack surface, was used to improve the adhesion between crack surfaces. Cracks were observed by scanning electron microscopy before and after the application of high-density electropulsing. To evaluate the healing effect of the SAPC during crack propagation,
High-cycle fatigue characteristics of quasi-isotropic carbon fiber reinforced plastic (CFRP) laminates [−45/0/45/90]s up to 108 cycles were investigated. To assess the fatigue behavior in the high-cycle region, fatigue tests were conducted at a frequency of 100 Hz, since it is difficult to investigate the fatigue characteristics in high-cycle at 5 Hz. Then, the damage behavior of the specimen was observed with a microscope, soft X-ray photography and a 3D ultrasonic inspection system. In this st
Carbon fiber reinforced plastic (CFRP) laminates are used as main structural members in many applications. Transverse cracks that form in 90° layers of CFRP laminates are mostly initial damage in the case where tensile loading is vertically applied to the 90° layers of CFRP laminates, and they are the origin of more serious damage of delamination and fiber breakage. It is thus important to predict quantitatively the transverse crack initiation of CFRP laminates subjected to cyclic loadin
It is time-consuming to conduct conventional hydraulic fatigue testing up to the very-high cycle fatigue (VHCF, N (number of cycles) ≥ 10 8 ) regime. Ultrasonic fatigue testing has been proposed as an accelerated alternative method. In this study, ultrasonic fatigue testing was conducted on interlaminar toughened quasi-isotropic carbon-fiber reinforced plastic (CFRP) laminates to evaluate the characteristics and mechanism of fatigue up to the VHCF regime. Hydraulic fatigue tests were conducted a
ABSTRACT Fatigue cracks were healed by controlling a high‐density electric current. The changes in the displacement distribution around the crack tip and the stress intensity factor before and after crack healing were evaluated quantitatively with a digital image collation method. According to the results, it was determined that the cracks were closed by approximately 2 to 7 µm in this study. On the other hand, the stress intensity factor decreased or increased depending on the conditions of the
