Search Results 1-20 of 479

  • ANALYTICAL INVESTIGATION ON GENERATION MECHANISM OF RESIDUAL STRESS BY RIVET JOINING  [in Japanese]

    末廣 大地 , 廣畑 幹人 , 中山 太士

    鋼構造論文集 27(107), 87-95, 2020-09

  • Is the assumption of linear elasticity within prosthodontics valid for polymers? —An exemplary study of possible problems

    SCHMIDT Alexander , SCHRADER Peer , FRENDEL Kay , SCHLENZ Maximiliane A. , WÖSTMANN Bernd , KOLLING Stefan

    … However, in dental biomaterial science it is mostly considered as linear elastic or elastic-plastic. … The aim of the present study was to evaluate, whether the assumption of elastic or elastic-plastic material behavior for PMMA is a practicable simplification or a potential source of error, especially considering clinical loading conditions. …

    Dental Materials Journal, 2020

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  • Calculation procedure of stress intensity factor for a reactor pressure vessel considering cladding during pressurized thermal shock events  [in Japanese]

    HIROTA Takatoshi , OGAWA Naoki , SAKAMOTO Hiroyuki

    … The Japan Electric Association code, JEAC 4206-2016 specifies a procedure for assessment of a reactor pressure vessel integrity against pressurized thermal shock (PTS) events considering irradiation embrittlement of the beltline region, which postulates a semi-elliptical flaw (10 mm in depth and 60 mm in length) beneath the cladding. … One option is employing 3D finite element analysis and the other option is to change plasticity correction factor to newly proposed correlation. …

    Journal of High Pressure Institute of Japan 58(3), 152-160, 2020

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  • Study on Influence of Heat Distribution by Gas Heating on Deformation  [in Japanese]

    OKIMI Yui , ASHIDA Ryo , IKUSHIMA Kazuki , KAWAHARA Atsushi , SHIBAHARA Masakazu , NATSUME Ryohei , ODA Kazuo , YAMAZAKI Yosuke , NAKATANI Mitsuyoshi

    溶接により変形した構造体を矯正する際のひずみ取り作業においては、ガス加熱がよく用いられている。ガス加熱においては溶接の場合とは異なり、変形は、入熱パラメータのみならず入熱密度分布の影響を大きく受け変化する。そこで本研究では、ガス加熱による入熱密度分布が変形に及ぼす影響についてFEM解析を用いて詳細に検討する。また、実験結果と比較することで、解析結果の妥当性についても検証する。

    Preprints of the National Meeting of JWS 2020s(0), 206-207, 2020

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  • Creep damage analysis for large-scale structure using Idealized Explicit FEM  [in Japanese]

    KITANI Yuji , Ninshu MA , NISHIKAWA Satoru , IKUSHIMA Kazuki , SHIBAHARA Masakazu

    石油火力発電プラントでは、高温強度、耐食性の向上を目的として高クロム鋼が使用されている。高クロム鋼は母材強度が優れている一方で、熱影響部はクリープ強度が低く損傷が生じる場合がある。また、破損による計画外停止やエネルギーロスの発生を避けるために、構造物の全体のクリープ損傷度を予測する必要がある。そこで本研究では、理想化陽解法FEMを用いた大規模クリープ解析手法の構築を行い、本手法の有用性について検討 …

    Preprints of the National Meeting of JWS 2020s(0), 208-209, 2020

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  • Study on Improvement of FE Analysis for Hot Cracking  [in Japanese]

    MAEDA Shintaro , Ninshu MA , SHIBAHARA Masakazu , YOSHIOKA Yuma , FUKUMOTO Shigeo

    高温割れは溶接施工時における重大な溶接欠陥であり、その発生を予測・防止することは非常に重要と言える。高温割れは,溶接金属の凝固に伴う冶金学的な因子と周囲の変形や拘束により生じる力学的な因子により生じる現象である.本研究では,溶接部に作用するひずみに加えて,溶接金属の凝固過程における偏析,凝固収縮を考慮した高温割れ解析手法を開発する.また開発手法の高温割れ発生予測に対する適用性について検討する.

    Preprints of the National Meeting of JWS 2020s(0), 114-115, 2020

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  • Prediction of solidification cracking during arc welding of 310S stainless steel in U-type hot cracking test  [in Japanese]

    LEE Jae-Hyeong , ITASAKA Yu , YAMASHITA Shotaro , OGURA Tomo , SAIDA Kazuyoshi

    … Solidification cracking can be explained by the intersection between the high temperature ductility curve and thermal strain curves; … The thermal strain curve was calculated using a finite element simulation model. …

    QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY 38(2), 68-75, 2020

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  • Application of Weld Distortion Analysis Based on Thermal Shrinkage Technique to Buttering Welding of Cylindrical Structure  [in Japanese]

    MURAKAMI Hiroki , TERASAKI Takeshi , MIYAZAKI Katsumasa , MAEDA Yoshihisa , OKANO Shigetaka , MOCHIZUKI Masahito

    Thermal elastic-plastic analysis has been applied as a tool to predict weld distortion, but calculation load is high and calculation time is extremely long. … Thermal shrinkage technique is expected as a promising technology that can achieve both high accuracy and high-speed calculation. …

    Journal of High Pressure Institute of Japan 58(2), 93-100, 2020

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  • Investigation of calculation procedure of stress intensity factor for fully circumferential flaw beneath reactor pressure vessel cladding  [in Japanese]

    HIROTA Takatoshi , OGAWA Naoki , SAKAMOTO Hiroyuki

    … <p>The Japan Electric Association code, JEAC 4206-2016 specifies a procedure for assessment of a reactor pressure vessel integrity against pressurized thermal shock (PTS) events which postulates a semi-elliptical flaw (10 mm in depth x 60 mm in length) beneath the cladding. …

    Transactions of the JSME (in Japanese) 86(882), 19-00308-19-00308, 2020

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  • RESIDUAL STRESS REDUCTION OF FILLET BOX WELDED JOINTS BY LOCAL HEATING USING INDUCTION HEATING DEVICE  [in Japanese]

    HIROHATA Mikihito , PHYO Aung May , ANI Kazunori

    <p> 鋼橋の溶接継手における疲労寿命の向上を目的に,高周波誘導加熱装置を用いた局所加熱による溶接残留応力の低減方法について一連の実験および解析的検討を実施した.すみ肉まわし溶接部を囲むように110mm×40mmの高周波誘導加熱装置を設置し,350℃まで加熱することで,340MPa程度の引張残留応力を30MPa以下まで低減する方法を提案した.また,局所加熱実験を熱弾塑性解析によりシミュ …

    Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)) 76(1), 29-40, 2020

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  • Efficient Modelling of Thin-plate Complex Structures Using Shell-solid Mixed Analysis  [in Japanese]

    生島 一樹

    日本船舶海洋工学会講演会論文集 Conference proceedings, the Japan Society of Naval Architects and Ocean Engineers (29), 379-388, 2019-11

  • Study on Stress-Strain Relations for Residual Stress Analysis of Welded Structures  [in Japanese]

    YANAGIDA Nobuyoshi , SAITO Koichi

    Thermal elastic plastic analysis is widely used to simulate residual stress of welded structures. … Stress-strain relations at temperatures from room temperature to melting temperature are necessary to perform the analysis. … The stress-strain relation data which is applied to the analysis significantly affects the analysis results. …

    The Proceedings of Ibaraki District Conference 2019.27(0), 901, 2019

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  • Effect of Welding Heat on Residual Stress in Butt Welded Zone of Medium-Diameter Pipe  [in Japanese]

    ISHII Yuya , MIYATA Yuka , NAKANO Yosuke , TOYOSHIMA Yoshiteru , YANAGIDA Nobuyoshi

    … The analysis object is 200A and 250A low carbon stainless steel. … The residual stress was calculated by unsteady heat conduction analysis and thermal elastic-plastic analysis with the heat input efficiency of the final layer as a parameter. …

    The Proceedings of the Materials and Mechanics Conference 2019(0), OS1305, 2019

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  • Practical Measurement of Residual Stresses Using Contour Method  [in Japanese]

    Ikushima Kazuki , Shibahara Masakazu , Kawajiri Yoshitaka , Okimi Yui , Uchida Tomoki , Akita Koichi , Suzuki Hiroshi , Morooka Satoshi

    … The measured residual stress distribution was compared with those measured by neutron diffraction method and calculated by thermal elastic plastic finite element analysis. …

    Journal of the Japan Society of Naval Architects and Ocean Engineers 30(0), 123-130, 2019

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  • Study on Influence of Jig Constraint on Welding Deformation Under Single-sided Submerged Arc Welding  [in Japanese]

    ASHIDA Ryo , IKUSHIMA Kazuki , MAEDA Shintaro , OZAKI Kento , NAGAKI Hayato , OMAE Toru , SHIBAHARA Masakazu

    片面サブマージアーク溶接時においては,治具拘束により変形量が小さく抑えられることが報形に及ぼす影響について,FEM 熱弾塑性解析を用いて検討する.さらに,拘束板を取り外した際のスプリングバック量についても検討する.

    Preprints of the National Meeting of JWS 2019f(0), 338-339, 2019

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  • Enhanced Idealized Explicit FEM for Predicting Welding Deformation in Complex Large-Scaled Structure and Application to the Real Structure  [in Japanese]

    IKUSHIMA Kazuki , MAEDA Shintaro , IESHITA Teruya , KAWAHARA Atsushi , ABE Yuuta , KIUCHI Hirotaka , SHIBAHARA Masakazu

    … In this research, to establish an analysis method which can predict the welding distortions in complex large-scale structures, we proposed a new analysis method based on the Idealized Explicit FEM. … In the proposed method, an algebraic multigrid method was introduced to the Idealized Explicit FEM to achieve an efficient analysis in realistic structures. … As a result, it was demonstrated that the proposed method has a high analysis accuracy. …

    QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY 37(4), 141-151, 2019

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  • Numerical Invesigation on Deformation Generated by Laser-arc Hybrid Welding of SBHS  [in Japanese]

    MORIOKA Kuya , HIROHATA Mikihito , MATSUMOTO Naoyuki , INOSE Koutarou

    橋梁用高降伏点鋼板の用途拡大に向け,部材製作の高効率化の観点からレーザ・アークハイブリッド溶接の適用を検討している.本稿では,ハイブリッド溶接による溶接変形抑止効果の検証のため,熱弾塑性解析によるシミュレーションを実施した結果を報告する.

    Preprints of the National Meeting of JWS 2019s(0), 62-63, 2019

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  • Study on Automation of Line Heating by Using Reinforcement Learning  [in Japanese]

    MAEKAWA Manami , HASHIZUME Hikaru , IKUSHIMA Kazuki , SHIBAHARA Masakazu

    AI とは人間の知的活動をコンピュータによって実現する技術であり,人間よりも膨大なデータ量を高速で扱えるという特徴を持つ.本研究では,FEM 熱弾塑性解析とAI を組合せることによる,線状加熱の自動化に向けた検討を行った.

    Preprints of the National Meeting of JWS 2019s(0), 78-79, 2019

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  • Accuracy Validation of Measurement of Through-Thickness Residual Stress in Multi-Pass Welded Joints of Very Thick Plate by Deep Hole Drilling Techniques  [in Japanese]

    KAWAI Shinji , OKANO Shigetaka , MURATA Tomohiro , MOCHIZUKI Masahito , NAGAI Takuya

    … Meanwhile, welding thermal elastic-plastic analysis with the finite element methods was performed to calculate the distribution of residual stress in the multi-pass welded joints. …

    Journal of High Pressure Institute of Japan 57(3), 162-170, 2019

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  • Accuracy Validation of Measurement of Transient Thermal Stress at Steel Welds by Synchrotron X-ray Diffraction Techniques  [in Japanese]

    OKANO Shigetaka , TSUJI Akihiro , ZHANG Shuoyuan , HASHIMOTO Tadafumi , SHOUBU Takahisa , MOCHIZUKI Masahito

    … <p>An advanced welding thermal elastic-plastic analysis, which has recently been developed by authors to improve both accuracy and reliability of welding simulation techniques, was applied to validate the measurement of transient thermal stress at steel welds by synchrotron X-ray diffraction techniques. …

    Journal of the Society of Materials Science, Japan 68(4), 325-331, 2019

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