Material Models for Accurate Simulation of Sheet Metal Forming and Springback

Fusahito YOSHIDA 한국소성가공학회 2010 기타자료 Vol.2010 No.6

For anisotropic sheet metals, modeling of anisotropy and the Bauschinger effect is discussed in the framework of Yoshida-Uemori kinematic hardening model incorporating with anisotropic yield functions. The performances of the models in predicting yield loci, cyclic stress-strain responses on several types of steel and aluminum sheets are demonstrated by comparing the numerical simulation results with the corresponding experimental observations. From some examples of FE simulation of sheet metal forming and springback, it is concluded that modeling of both the anisotropy and the Bauschinger effect is essential for the accurate numerical simulation.

Reduction of Springback of Sheet Metals by Bottoming

Takayuki Ogawa,Atsushi Hirahara,Fusahito Yoshida 한국소성가공학회 2010 기타자료 Vol.2010 No.6

The effect of bottoming on the reduction of springback is investigated by performing V-air-bending experiment on a high strength steel sheet of TS590MPa and the corresponding FE simulation. From the experiment, it was found that the springback is drastically decreased with increasing bottoming force. This is mainly due to the reduction of bending moment by compressive load acting normally to the sheet. At an early stage of bottoming, springback is also influenced by the change of geometrical rigidity of the bent sheet due to the straightening of ridge line warp. Since bottoming is a process of reverse deformation of tension-compression, the Bauschinger effect of materials should be taken into account for its accurate numerical simulation. 3D FE simulation using Yoshida-Uemori kinematic hardening model predicts well the bottoming effect.

Elasto-Plasticity Behavior of Type 5000 and 6000 Aluminum Alloy Sheets and Its Constitutive Modeling

Shohei TAMURA,Satoshi SUMIKAWA,Hiroshi HAMASAKI,Takeshi UEMORI,Fusahito YOSHIDA 한국소성가공학회 2010 기타자료 Vol.2010 No.6

To examine the deformation characteristic of type 5000 and 6000 aluminum alloy sheets, uniaxial tension, biaxial stretching and in-plane cyclic tension-compression experiments were performed, and from these, r-values (r?, r45 and r90), yield loci and cyclic stress-strain responses were obtained. For the accurate description of anisotropies of the materials, high-ordered anisotropic yield functions, such as Gotoh’s biquadratic yield function and Barlat’s Yld2000-2d, are necessary. Furthermore, for the simulation of cyclic behavior, an advanced kinematic hardening model, such as Yoshida-Uemori model (Y-U model), should be employed. The effect of the selection of material models on the accuracy of the springback prediction was discussed by performing hat bending FE simulation using several yield functions and two types of hardening laws (the isotropic hardening model and Y-U model)

MAGNETIC PROPERTIES OF FePt₃ ORDERED ALLOY

H.Yoshida,H.Fujimorl,T.Kaneko,S.Abe,K.Watanabe,M.Matsumoto,T.Yoshida,T.Kanomata 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.5

The magnetic properties for Fe₂₄Pt_(76) and Fe_(26)Pt_(74) have been investigated. The temperature vs. magnetic susceptibility curve for Fe₂₄Pt_(76) had no peak near the Neel temperature. The magnetization process at 4.2 K showed only a linear variation up to the high magnetic field of 240 kOe. That for Fe_(26)Pt_(74) at 77 K showed a metamagnetic transition at 100 kOe. These properties were discussed on the basis of a band picture.

Incremental Parsing in Conditionals and Relative Clauses in Korean

Masaya Yoshida,윤수원,신정아 한국생성문법학회 2022 생성문법연구 Vol.32 No.4

The strong head-finality of Korean raises many potential challenges to incremental parsing. In languages like Korean, there is normally no indication of clause structure before the parser encounters the verb or the relative head at the end of the clause. This uncertainty of clause structure can potentially give rise to processing difficulty of verbs in head-final languages. Developing our earlier studies in Japanese (Yoshida 2006), we present four series of experiments in Korean (offline and online) to show that there are, however, cases where the processing of clause-final verbs can indeed be predicted and facilitated.

Interrogative Feature Checking in Japanese and Korean

( Keiko Yoshida ),( Tomoyuki Yoshida ) 한국언어정보학회 1996 국제 워크샵 Vol.1996 No.-

This paper discusses the feature checking mechanism of interrogative sentences in Japanese and Korean. We first focus on a phenomenon of omitting question markers in informal speech in Japanese and attempt to provide an account for it within the framework of Principles and Parameters approach. We argue that question markers can be omitted only if interrogative features of the sentence can be properly checked. In particular we claim that I-to-C head-movement is one of the options for interrogative feature checking in Japanese as well as languages without question markers. A close examination of Korean reveals certain differences between Korean and Japanese. Some theoretical consequences from this analysis are also discussed.

Alcohol Consumption and Gender Difference

YOSHIDA Keiko 계명대학교 산학연구소 2013 經營經濟 Vol.46 No.1

Purpose ? The purpose of this study is to examine drinking behavior by using surveys in both in Japan and the United States. Design/Methodology ? This study is based on data from two surveys from Japan and the United States. Linear regression model is used for statistical analysis. Findings ? The empirical results show that although gender difference of alcohol consumption decreases in the subsample of people with higher education. Females with a college degree are more likely to drink than females with less schooling. Implications ? The research examined the factors of drinking behavior and suggested gender difference in alcohol consumption can be various.

Reduction of Outdoor and Indoor Ambient Dose Equivalent after Decontamination in the Fukushima Evacuation Zones

Yoshida-Ohuchi, Hiroko,Kanagami, Takashi,Naitoh, Yutaka,Kameyama, Mizuki,Hosoda, Masahiro The Korean Association for Radiation Protection 2017 방사선방어학회지 Vol.42 No.1

Background: One of the most urgent issues following the accident at the Fukushima Daiichi nuclear power plant (FDNPP) was the remediation of the land, in particular, for residential area contaminated by the radioactive materials discharged. In this study, the effect of decontamination on reduction of ambient dose equivalent outdoors and indoors was evaluated. The latter is essential for residents as most individuals spend a large portion of their time indoors. Materials and Methods: From December 2012 to November 2014, thirty-seven Japanese single-family detached wooden houses were investigated before and after decontamination in evacuation zones. Outdoor and indoor dose measurements (n = 84 and 114, respectively) were collected based on in situ measurements using the NaI (Tl) scintillation surveymeter. Results and Discussion: The outdoor ambient dose equivalents [$H^*(10)_{out}$] ranged from 0.61 to $3.71{\mu}Sv\;h^{-1}$ and from 0.23 to $1.32{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The indoor ambient dose equivalents [$H^*(10)_{in}$] ranged from 0.29 to $2.53{\mu}Sv\;h^{-1}$ and from 0.16 to $1.22{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The values of reduction efficiency (RE), defined as the ratio by which the radiation dose has been reduced via decontamination, were evaluated as $0.47{\pm}0.13$, $0.51{\pm}0.13$, and $0.58{\pm}0.08$ ($average{\pm}{\sigma}$) when $H^*(10)_{out}$ < $1.0{\mu}Sv\;h^{-1}$, $1.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$ < $2.0{\mu}Sv\;h^{-1}$, and $2.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$, respectively, indicating the values of RE increased as $H^*(10)_{out}$ increased. It was found that the values of RE were $0.53{\pm}0.12$ outdoors and $0.41{\pm}0.09$ indoors, respectively, indicating RE was larger outdoors than indoors. Conclusion: Indoor dose is essential as most individuals spend a large portion of their time indoors. The difference between outdoors and indoors should be considered carefully in order to estimate residents' exposure dose before their returning home.

Analysis of near weld stress field based on strain measurement and physical mesomechanics

Yoshida, S.,Sasaki, T.,Usui, M.,Park, I. K. Springer Science + Business Media 2016 Physical mesomechanics Vol.19 No.1

<P>Stresses induced by welding are analyzed from the viewpoint of material deformation behavior. Strain gages are used to measure the residual stresses, and electronic speckle-pattern interferometry is used to analyze the response of the welded work to external force. A tensile load is applied to a butt-welded, thin-plate steel specimen, and the resultant strain field is analyzed with the electronic speckle-pattern interferometry. Comparison is made with the case of a nonwelded specimen of the same material and dimension. The analysis indicates that the residual stress due to welding makes the normal strain due to the external tensile load asymmetric. The asymmetry enhances shear and rotational modes of deformation, generating stress concentration at a point away from the weld where the residual stress is substantially negligible. The observed features are discussed based on physical mesomechanics. Analysis reveals plastic deformation like behavior in the response of the welded specimen to the external force.</P>

Virulence-associated Genome Sequences of Pasteurella canis and Unique Toxin Gene Prevalence of P. canis and Pasteurella multocida Isol

Yoshida Haruno,Kim Jung-Min,Maeda Takahiro,Goto Mieko,Tsuyuki Yuzo,Shibata Sachiko,Shizuno Kenichi,Okuzumi Katsuko,Kim Jae-Seok,Takahashi Takashi 대한진단검사의학회 2023 Annals of Laboratory Medicine Vol.43 No.3

Background: Comparative analysis of virulence factors (VFs) between Pasteurella canis and Pasteurella multocida are lacking, although both cause zoonotic infections. We determined the virulence-associated genome sequence characteristics of P. canis and assessed the toxin gene prevalence unique to P. canis among clinical isolates of P. canis and P. multocida. Methods: We selected 10 P. canis and 16 P. multocida whole-genome sequences (WGSs) from the National Center for Biotechnology database. The VFanalyzer tool was used to estimate P. canis-characteristic VFs. Amino acid sequences of VFs were compared with multiple-aligned sequences. The genome structure containing P. canis-characteristic and adjacent loci was compared to the corresponding P. multocida genome structure. After designing primer sequences and assessing their accuracy, we examined the gene prevalence of the P. canis-characteristic VFs using PCR among clinical isolates of P. multocida and P. canis. Results: Using VFanalyzer, we found virulence-associated cytolethal distending toxin (cdt)A–cdtB–cdtC loci common to all P. canis WGSs that were not found in P. multocida WGSs. Similarities in the multiple alignments of CdtA–CdtB–CdtC amino acid sequences were found among the 10 P. canis WGSs. Shared or similar loci around cdtA–cdtB–cdtC were identified between the P. canis and P. multocida genome structures. The PCR-based cdtA–cdtB–cdtC prevalence differed for P. canis and P. multocida clinical isolates. Conclusions: P. canis-specific cdtA–cdtB–cdtC prevalence was identified among clinical isolates. These three loci may be unique toxin genes and promising targets for the rapid identification of P. canis in clinical settings.