研究者詳細 - 判治　剛

論文 - 判治　剛

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Local strain based low cycle fatigue assessment of gusset plates in steel truss bridges under earthquake 査読有り

Chao Jiang, Takeshi Hanji, Kazuo Tateishi, Masaru Shimizu

Proceedings of the ISSS 2019 2019年11月

担当区分：責任著者記述言語：英語

Steel truss bridges are widely used for intermediate spans because of its light weight and high load-carrying capacity. Failure accidents of truss bridge have shown that fracture of some members can lead to collapse of the whole bridge, called fracture critical member (FCM). In this study, from the viewpoint of low cycle fatigue, dynamic behavior of FCM under great earthquake was discussed. The results of finite element analysis indicated that large strains were locally occurred at the end of fillets of a gusset plate and around the boundary between the gusset and main chords, which have the possibility to become cracking sites due to low cycle fatigue.

Estimation of fatigue crack propagation behavior in steel plate subjected to out of plane bending 査読有り

Kentaro Horio, Kazuo Tateishi, Masaru Shimizu, Takeshi Hanji

Proceedings of the ISSS 2019 2019年11月

Fatigue strength of cruciform joints and longitudinal joints with laser-arc hybrid welding 査読有り

Takeshi Hanji, Kazuo Tateishi, Masaru Shimizu, Daisuke Uchida, Koichi Asano, Ryosuke Kimura

Welding in the World 63 巻 ( 5 ) 頁： 1379-1390 2019年9月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This study examined the fatigue strength of cruciform joints and longitudinal joints fabricated with laser-arc hybrid welding. Load-carrying and non-load-carrying cruciform welded joints with plate thicknesses of 8, 16, and 25 mm were tested under tensile cyclic loads and out-of-plane bending cyclic loads. In longitudinal joints, four-point bending fatigue tests were performed on plate girders with flanges and a web connected by laser-arc hybrid welding. When assembling the plate girder, tack welds were installed at the flange-to-web connection to clarify their effect on the fatigue strength of the longitudinal joints. Measurements of weld toe profiles and residual stress were also conducted. The residual stress was measured using X-ray diffraction. The test results revealed that the fatigue strengths of hybrid welded joints are equivalent to those of arc welded joints and satisfy the fatigue design curves specified by the Japanese Society of Steel Construction. In addition, the effect of plate thickness on the fatigue strength was observed in hybrid welded joints as well as in arc welded joints.

DOI： 10.1007/s40194-019-00745-w

Slip coefficient and ultimate strength of high-strength bolted friction joints with compact bolt spacing and edge distance 査読有り

Shogo Kiyokawa, Kazuo Tateishi, Takeshi Hanji, Masaru Shimizu

International Journal of Steel Structures 19 巻 ( 4 ) 頁： 1191-1201 2019年8月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In current design codes, the minimum bolt spacing and edge distance for high-strength bolted friction joints are specified based on the bolt diameter, regardless of the plate thickness or steel strength. However, the mechanical performance of joints with a more compact bolt spacing than that given in the current design specifications has been little examined. In this study, the slip and ultimate strength of high-strength bolted joints with a compact bolt spacing and edge distance were investigated. Tensile tests were conducted on friction-type joints with various bolt arrangements. The use of a compact bolt arrangement was not observed to have a negative influence on the slip strength in these tests. The estimated strengths corresponding to the experimentally observed failure modes were found to agree fairly well with the experimental results within a 10% error. A parametric finite element analysis was also conducted to investigate the influence of the bolt arrangement on the slip coefficient. It was concluded that the bolt spacing and edge distance have little influence on the slip coefficient.

DOI： 10.1007/s13296-018-0199-3

タック溶接を含むレーザ・アークハイブリッド溶接継手の疲労強度査読有り

判治剛，舘石和雄，清水優，内田大介，木村陵介，浅野浩一

溶接学会論文集 37 巻 ( 3 ) 頁： 99-107 2019年7月

Fatigue strength of transverse attachment joints with single-sided weld using low transformation temperature welding consumable 査読有り

Takeshi Hanji, Kazuo Tateishi, Suguru Kano, Masaru Shimizu, Tadahisa Tsuyama, Toshio Takebuchi

The 72nd Annual Assembly of International Institute of Welding 頁： XIII-2809-19 2019年7月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This study investigated the applicability of low transformation temperature (LTT) consumables to improve fatigue strength against weld root failure. Transverse attachment joints formed by single-sided welding, similar to rib-to-deck connections in orthotropic steel bridge decks, were fabricated using an LTT welding consumable and conventional welding consumable. Fatigue tests were performed with out-of-plane bending loads using a vibration-type fatigue testing machine. The test results indicated that higher fatigue strength can be achieved in the joint with an LTT consumable compared with a conventional one. In addition, residual stresses around the weld bead were clarified by X-ray diffraction measurements and finite element analyses. The results revealed that the LTT consumable can reduce residual stress around the weld and also introduce compressive residual stress to the weld root, which can contribute to improved fatigue strength.

鋼床版Uリブ・デッキプレート溶接部の内在き裂に対するフェーズドアレイ超音波探傷の測定精度査読有り

服部雅史，牧田通，舘石和雄，判治剛，清水優，八木尚人

土木学会論文集A1 74 巻 ( 3 ) 頁： 516-530 2018年12月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）

鋼床版のUリブ・デッキプレート溶接部を対象として，デッキプレート方向もしくは溶接ビード方向に進展する内在き裂を検出できる非破壊検査手法と，その測定精度について検討した．本研究では，鋼床版に磁石で固定でき，バッテリ駆動のモータにより橋軸方向に電動走行できる治具を取り付けたフェーズドアレイ超音波探傷装置を用いた．本装置によりデッキプレートおよび溶接ビードに内在する疲労き裂を同時に探傷することが可能である．振動式疲労試験機により，様々な寸法のデッキ進展型もしくはビード進展型の疲労き裂を導入した試験体を製作し，測定方法の検討，測定精度の検証，塗膜の影響の確認を行い，本手法が十分な検出性能を有していることを示した．

DOI： 10.2208/jscejseee.74.516

レーザークリーニングを施した溶接継手の疲労強度査読有り

Cut Atika Putri，舘石和雄，判治剛

鋼構造論文集 25 巻 ( 100 ) 頁： 73-76 2018年12月

腐食した鉄筋の疲労寿命予測査読有り

判治剛，アフマドザイニアマチュラ，舘石和雄，清水優

鋼構造年次論文報告集 26 巻頁： 804-810 2018年11月

疲労き裂部への高力ボルト当て板補強におけるすべり耐力に関する検討査読有り

清川昇悟，判治剛，清水優，舘石和雄

鋼構造年次論文報告集 26 巻頁： 277-283 2018年11月

レーザ・アークハイブリッド溶接を用いた十字継手の疲労強度査読有り

判治剛，舘石和雄，清水優，内田大介，木村陵介，浅野浩一

溶接学会論文集 36 巻 ( 4 ) 頁： 219-229 2018年10月

鉄道橋Ｉビーム桁支点部の疲労き裂とその補修対策による延命効果査読有り

判治剛，舘石和雄，清水優，岩井将樹，池頭賢，丹羽雄一郎

土木学会論文集A1 74 巻 ( 2 ) 頁： 290-305 2018年8月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）

鉄道橋Iビーム桁の支点部において，ウェブと下フランジの境界部に沿って疲労き裂が発生する事例が報告されている．このき裂に対しては，応急対策としてストップホールが施されることが多いが，比較的早期にき裂が再発生した報告もあり，その延命効果を定量的に評価する手法の確立が望まれている．そこで本研究では，Iビーム桁支点部の疲労き裂に対するストップホールの効果を疲労試験と有限要素解析により検討した．疲労試験は，供用後に撤去されたIビーム桁を用い，き裂が発見された支点まわりの挙動を模擬して行った．その結果，補修後の疲労寿命がストップホール縁の応力範囲により整理できることを示した．さらに解析により，補修時のき裂長とストップホール縁の応力範囲の関係を明らかにし，実橋に施したストップホールの疲労寿命予測を試みた．

DOI： 10.2208/jscejseee.74.290

Effect of weld penetration on low cycle fatigue strength of load-carrying cruciform joints 査読有り

Takeshi Hanji, Kazuo Tateishi, Yuko Ohashi, Masaru Shimizu

The 71st Annual Assembly of International Institute of Welding 頁： XIII-2749-18 2018年7月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This study examined the low cycle fatigue behavior of load-carrying cruciform welded joints containing incomplete penetration. Five types of specimens with different sizes of weld penetrations and weld leg lengths were tested under cyclic plastic strains. During testing, cracking behavior was observed on the side surface of the specimen. The test results revealed that the fatigue strength and cracking patterns depend on the ratio of the weld penetration to the main plate thickness and the ratio of the weld leg length to the main plate thickness, respectively. Elasto-plastic finite element analyses including the effective notch concept were then performed. The results indicate that the fatigue strength and cracking pattern of the specimens can be correlated with the local strain distribution around the effective notch.

溶接止端部に生じる局部ひずみ範囲の簡易推定法査読有り

清水優，舘石和雄，判治剛，本田直也

鋼構造論文集 25 巻 ( 97 ) 頁： 61-66 2018年3月

当て板補強が施されたストップホールのひずみ推定法査読有り

清川昇悟，舘石和雄，判治剛，清水優，中山裕哉

構造工学論文集 64A 巻頁： 445-454 2018年3月

当て板によるストップホール部の応力集中低減効果査読有り

清川昇悟，舘石和雄，判治剛，清水優，中山裕哉

構造工学論文集 64A 巻頁： 435-444 2018年3月

鋼管集成橋脚に設けられたせん断パネルダンパー溶接部の低サイクル疲労評価手法査読有り

清水優，舘石和雄，判治剛，杉山裕樹，曽我恭匡，足立陸，野田拓史

鋼構造論文集 24 巻 ( 96 ) 頁： 17-29 2017年12月

鉄道橋Iビーム桁支点首部における疲労き裂対策の効果検証査読有り

池頭賢，丹羽雄一郎，松本健太郎，判治剛，舘石和雄

鋼構造年次論文報告集 25 巻頁： 661-666 2017年11月

Slip coefficient and fracture strength of high strength bolted friction joints with compact bolt spacing and edge distance 査読有り

Shogo Kiyokawa, Kazuo Tateishi, Takeshi Hanji, Masaru Shimizu

Proceedings of the ISSS 2017 頁： 223-226 2017年11月

担当区分：筆頭著者記述言語：英語

As for bolt spacing and edge distance of high strength bolted joints, minimum values are specified as a function of bolt diameter D, regardless of plate thickness and steel strength. That is, the minimum value is not clearly defined by mechanical performance of the joint. Moreover, there is little knowledge on the performance of the joint with the bolt spacing more compact than given in the current design specifications. This study investigates slip and fracture strength of high strength bolted joints with compact bolt spacing and edge distance. Tensile coupon tests on frictional joints with various bolt arrangement were conducted. It was not clearly observed the negative influence of compact bolt arrangement on the slip strength. The fracture strengths estimated from the cross
sectional area where the fracture occurred and steel strength of the plate agreed with the experimental results within 10% error in all fracture modes. Parametric analyses were also conducted to investigate the influence of the bolt arrangement to the slip coefficient. It was concluded that the bolt spacing and edge distance have small influence on the slip
coefficient.

Fatigue life prediction of corroded reinforcing steel bars 査読有り

Takeshi Hanji, Niamatullah Ahmadzai, Kazuo Tateishi, Masaru Shimizu

Proceedings of the ISSS 2017 頁： 478-481 2017年11月

担当区分：筆頭著者記述言語：英語

In this study, fatigue lives of corroded reinforcing steel bars were investigated. Several kinds of rebars consisting of different yield stress and rib shapes were used. The rebar was galvanically corroded to three levels, which are considered as a percentage of mass reduction of 5%, 10% and 15% respectively. Fatigue tests were carried out under constant stress amplitude. The test results revealed that the fatigue life of the corroded rebar decreases as the corrosion level increases. Then, 3D elasto-plastic finite element analyses were conducted with models reflecting surface profiles of the corroded rebar. The analysis results indicated that a cross section where the maximum local strain occurs corresponds to a cracking site observed in the test. Finally, the fatigue life of the corroded rebar was predicted by crack propagation calculations based on linear fracture mechanics. There are relatively good agreements between the prediction and the test results.

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