Home | Matsuda Labratory

Aim

"How do it break? (fracture mechanism)" and "How long can it be used ? (strength and life)" are need to know because mechanical structures require high safety and reliability. It is very important to use the materials after wide mechanical tests because using materials without fully understanding the mechanical properties is carried risk. In this labratory, the fracture mechanism and the strength reliability of structural materials (i.e., ceramics, plastics, metals, and composite materials (CFRP)) are investigated via mechanical tests and theoretical analysis. We aim to propose "how to use" structural materials.

Member

( 01 )

Member

Staff

Associate professor

　Shinya MATSUDA

Graduate students (master's program)

　M2　Mikio AMUL-RU FUKUTAKE

　M2　Ryoya UEHARA

M2　Yuya FUJIMOTO

Undergraduates

4 year

Koki TADA

Saki KOYANO

Kota TAKAHASHI

Yukimune HAYASHI

Hina MORIYAMA

　Kanata SHIBUTA

3 year　

Researches

( 02 )

Researches

Brittle materials (Ceramics, Glass)

Keywords: Brittle fracture, Time-dependent fracture, Contact fracture, Thermal shock, Static, dynamic, and cycle fatigue

Strength and fracture

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.

Fig. Strength and fracture of ceramics.

Related publications

・S. Matsuda, J. Takenaka, K. Arii, K. Ogi, Eng. Fract. Mech., 255(1), 107924 (2021)

・S. Matsuda, Int. J. Fract., 215(1-2), pp.175-182 (2019)

・S. Matsuda and T. Nakada, Eng. Fract. Mech., 197(15), pp.236-247 (2018)
・S. Matsuda, J. Mater. Sci., 51(11), pp.5502-5513 (2016)

Composites(CFRP, GFRP)

Keywords: Carbon fiber reinforced plastics(CFRP), Glass fiber reinforce, plastics(GFRP), Punching, Shear cutting, Out-of-plane loading, Recycling

Punching and Shear cutting

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 CFRP and GFRP laminates during punching and shear cutting.

Fig. Piercing hole images of CFRP laminate after punching and drop-weight impact punching device.

Related publications

・S. Matsuda, K. Mabe, K. Ogi, S. Yashiro, Y. Kakudo，J. Compos. Mater., 55(28), 4111-4124 (2021).

Recycling applied to electrical treatment

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 electrical treatment.

Fig. Carbon fibers in CFRP laminate after electrical treatment.

Related publications

・K. Oshima, M. Hosaka, S. Matsuda, S. Satokawa（Coressponding authors K. Oshima and S. Matsuda)，Sep. Purif. Technol.251(15)2020.11
・S. Matsuda, K. Oshima, M. Hosaka, S. Satokawa（Coressponding authors S. Matsuda and K. Oshima)，Compos. Struct.234(15) 2020.2, 111665
・K. Oshima, S. Matsuda, M. Hosaka, S. Satokawa（Coressponding authors K. Oshima and S. Matsuda)，Sep. Purif. Technol.231(16)2020.1, 115885

Stochastic process

Markov process, Failure and fracture, Statistical approach

In order to ensure strength reliability of materials in the engineering field, it is necessary to probabilistically understand the degradation of materials changing over time. In the field of reliability engineering, the transition of the phenomenon has been discussed using the theory of stochastic processes. However, the recent spread of applied research based on stochastic processes in the field of material and structural reliability is not sufficient. One of the causes is that advanced analysis software easier to use because the remarkable development of computer technology in recent years has been developed remarkably. Researchers sometimes choose convenient software, and accept the results without knowing the principle of analysis. This produces that the obtained important results may be overlooked because the basic theory used in analysis software is not understood. Therefore, re-recognizing the stochastic processes is important to develop reliability engineering. We try to apply stochastic process theory for the problems of damage, failure and fracture of materials.