RESEARCHES
Fracture and strength of brittle materials
(Ceramics and Glass)
Since the 1970s, ceramics have been actively applied as structural members in the wake of the oil crisis. After that, strength reliability was studied from the latter half of the 1980s to the first half of the 1990s, but from the latter half of the 1990s, process research to raise the reliability of the material itself became active. In recent years, ceramics have been applied to structural members such as ceramic ball and microdevices such as SOFC and MEMS. Consequently, with the need to assure their reliability, there is a need to clarify the fracture characteristics of the brittle ceramics. We aim to experimentally and theoretically clarify the strength and life characteristics in various load modes such as static load, thermal shock, contact, and variable load, and to propose a simple test method.
Representative publication
S. Matsuda, J. Takenaka, K. Arii, K. Ogi, Eng. Fract. Mech., Volume 255, 1 October 2021, 107924
S. Matsuda, T. Nakada, Eng. Fract. Mech., Volume 197, 2018, 236-247
S. Matsuda, T. Takahashi, Eng. Fract. Mech., Volume 77, 2010, 2601-2609
Punching and shear cutting of composites
(CFRP and GFRP)
In industrial processes, piercing and trimming are essential because composite structures are usually manufactured in a near-net shape to reduce machining operations. Punching and shear cutting using out-of-plane shear loading can be expected to increase productivity. Matrix cracks and delaminations will be generated without optimization of the cutting conditions. This study experimentally and analytically evaluates the damage extension in carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plasticsGFRP laminates during punching and shear cutting.
Representative publication
S. Matsuda, K. Mabe, K. Ogi, S. Yashiro, Y. Kakudo, J Compos. Mater., 55(28) 2021.12, 4111-4124
Recycling applied to thermal decomposition and electrical treatments for CFRP
The demand for CFRP as primary structural components of airplanes and automobiles has been increasing in recent years because of their high specific strength and rigidity. On the other hand, since the lifespan of airplanes and automobiles is only approximately 30 and 10 years, respectively, large volumes of CFRP are discarded as waste materials. Carbon fiber being an expensive material, the recycling technology of used CFRP has been gaining attention from the economic perspective and its potential for reducing the environmental burden. It needs to recycling method for CFRP, which can be selectively recovered carbon fibers. In this study, we experimentally investigate the optimal resin removal method using the thermal decomposition treatment and the electrical treatment.
Representative publication
S. Matsuda, S. Koyano, K. Oshima, Compos A, 178, 2024, 107991.
K. Oshima, S. Matsuda et al, Adv. Compos. Mater., Published online: 09 Sep 2022
S. Matsuda, M. Miyake, K. Oshima, Compos. Struct.292(15)2022.7, 115603
K. Oshima, S. Matsuda et al，Sep. Purif. Technol. 251(15)2020.11, 117296
S. Matsuda, K. Oshima et al, Compos. Struct.234(15)2020.2, 111665
K. Oshima, S. Matsuda et al，Sep. Purif. Technol.231(16)2020.1, 115885