Papers by Toshiyuki UENOYA
SPIE Proceedings, 2008
In this study, we develop a new 3D miniature blood vessel searching system by using near-infrared... more In this study, we develop a new 3D miniature blood vessel searching system by using near-infrared LED light, a CMOS camera module with an image processing unit for a health monitoring system (HMS), a drug delivery system (DDS) which requires very high performance for automatic micro blood volume extraction and automatic blood examination. Our objective is to fabricate a highly
In this paper, damage progression process of plain-woven CF/epoxy composites was investigated und... more In this paper, damage progression process of plain-woven CF/epoxy composites was investigated under cyclic loading. Damage state, damage degree and its location were observed in the flat-wise direction of the specimen by using thermo-elastic stress analysis (TSA). The results of TSA showed that transverse cracks initiated and accumulated in the wefts at early fatigue stage. Each location of the damage had degree of different damage magnitude at any fatigue cycles. In order to obtain accurate damage information, thermo-elastic damage analysis (TDA) was conducted. A quantitative evaluation of damage accumulation level in plain-woven CF/epoxy composites was proposed based on the concept of damage parameters (such as damage level, damage area ratio and damage value) given by TDA results.
In this paper, the residual life and the creep damage for glass fiber reinforced plastics are stu... more In this paper, the residual life and the creep damage for glass fiber reinforced plastics are studied experimentally. For this purpose, emphasis is placed upon introducing a new damage parameter defined by acoustic emission (AE) intensity in order to evaluate the micro-damage accumulation generated before macro-crack initiation in a composite. Short-term creep experiments were carried out on three types of specimens, consisting of glass fiber fabric reinforced epoxy laminated composites with different weaves, counts, densities and thickness. The single-edge notched specimens were subjected to a series of stepwise loadings with increasing peak loads, in edgewise four-point bending so that tensile stress arose at the front end of the notch. AE activity was monitored with measuring mechanical displacement during a test using various AE intensities, which were analyzed in detail. The new damage parameter showed a good correlation with a conventional damage parameter defined by non-elast...
Journal of the Society of Materials Science, Japan
Materials Science Forum
The extended band structures of cold-rolled high Cr steel sheets are recrystallization resistant,... more The extended band structures of cold-rolled high Cr steel sheets are recrystallization resistant, and tend to become the so-called grain colony as a recovered state. It is shown that a novel approach involving strain-path change by introducing one-pass ECAP prior to cold rolling facilitated recrystallization. Indeed, recrystallization temperature was reduced by 100 °C, compared with cold rolling alone imposing the same equivalent strain. Dense deformation bands introduced during ECAP perturbed the banded structures and enhanced the recrystallization at final annealing.
Proceedings of the 1992 Annual Meeting of JSME/MMD
The proceedings of the JSME annual meeting
The proceedings of the JSME annual meeting
The proceedings of the JSME annual meeting
The proceedings of the JSME annual meeting
The Proceedings of the JSME Symposium on Welfare Engineering
The Proceedings of the JSME Symposium on Welfare Engineering
The Proceedings of the Materials and Mechanics Conference
The Proceedings of Conference of Kansai Branch
The Proceedings of Conference of Kansai Branch
The Proceedings of Conference of Kansai Branch
The Proceedings of the JSME Materials and Processing Conference (M&P)
In this study, the damage progression process for plain-woven carbon fabTic composites (PW-CFCs) ... more In this study, the damage progression process for plain-woven carbon fabTic composites (PW-CFCs) under cyclic loading was investigated. Under cyclic loading, the damage progressien was estimated intermittently by using the thermo-elastic damage analysis (TDA) method. Crack densitiy for each layer of the specimen was also estimated at several stages of fatigue. It was found from these results that the damage progression process was divided into three stages. In the first stage, especially, the damage accumulation occurred independently in the PW-CFC specimen and progressed easily along the transverse fiber bundles. All experimental results showed that the damage progressien in the first fatigue stage was explained by consiaering damage-units (a unit area of damage progression and aceumulatien).
The Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics
The extended band structures of as-cold-rolled high Cr steel sheets are recrystallisation-resista... more The extended band structures of as-cold-rolled high Cr steel sheets are recrystallisation-resistant, and tend to become an aggregate of the so-called grain colonies as a partially recovered state after final annealing. Such band structures diminish the formability and become the origin of the so-called ridging. A novel processing is shown, which involves strain-path change by introducing one-pass ECAP prior to cold-rolling, and facilitates recrystallisation. Indeed, recrystallisation temperature was reduced by 100℃, compared with cold rolling alone imposing the same equivalent strain. Grain-scale microshear bands introduced during one-pass ECAP perturbed the banded structures in post-ECAP cold rolling and enhanced the recrystallisation at the final annealing.
The Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics
The grain refinment is prerequisite for metallic matrials to improve strength and toughness. Equa... more The grain refinment is prerequisite for metallic matrials to improve strength and toughness. Equal-channel angular pressing (ECAP), one of the severe plastic deformation to produce bulk ultra-fine grain metals, have intensely been studied for the last two decades for many metallic materials. However, there has been no report on the application of ECAP to metallic materials with martensitic structure. Stainless steels with some Ni and Mn contents and extremely low carbon can be quenched to have very soft martensitic structures. In this study, ECAP have first successfully been applied to stainless steels sheets with martensite structures to produce ultrafine grain microstructures. Microstructural development during several passes of ECAP and mechanical properties were mainly investigated. Hot-rolled sheets of extremely low-C,N-12%Cr-4.5%Mn-3.5%Ni stainless steel were quenched form 850℃ to obtain martensite phase. Then, they were pressed by ECAP until six passes. Hardness after ECAP increased with an increase of pressing until six passes. The initial grains size before ECAP was about 30μm, then the final grain size decreased to about 200nm. It was observed by TEM that the grains after six passes were still extended in the shear direction and have dislocations inside them. Therefore, microstructures were deformation structures rather than the so-called UFG structures after six passes. Most importantly, however, the selected area diffraction patterns (SADP) revealed local austenite phase in grains with high dislocation density. It is considered that the austenite phase was generated by the inverse transformation induced by intense shear deformation under high hydrostatic stress. The so-called deformation-induced inverse transformation (DIIT) from martensite to austenite were reviewed, and the mechanism are discussed.
The Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics
The extended band structures of as-cold-rolled high Cr steel sheets are recrystallisation-resista... more The extended band structures of as-cold-rolled high Cr steel sheets are recrystallisation-resistant, and tend to become an aggregate of the so-called grain colonies as a partially recovered state after final annealing. Such band structures have {100} texture and diminish the formability and become the origin of the so-called ridging. A novel processing is shown, which involves strain-path change by introducing one-pass ECAP prior to cold-rolling, and facilitates recrystallisation. Indeed, recrystallisation temperature was reduced by 100℃, compared with cold rolling alone imposing the same equivalent strain. Grain-scale microshear bands introduced during one-pass ECAP perturbed the banded structures in post-ECAP cold rolling and enhanced the recrystallisation at the final annealing.
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Papers by Toshiyuki UENOYA