Faculty Profiles - HANJI Takeshi

Papers - HANJI Takeshi

Division display 141 - 160 of about 245 ／ All the affair displays >>

A prediction method for extremely low cycle fatigue crack propagation of structural steels Reviewed

Nao Terao, Takeshi Hanji, Kazuo Tateishi, Masaru Shimizu

Proceedings of the ISSS 2015 page： 387-388 2015.11

Authorship：Lead author Language：English

Extremely low cycle fatigue, which is caused by large cyclic deformation with small number of loading repetition, is one of the main failure modes in steel structures during earthquake. In this study, crack propagation behavior of structural steels for welded structures (not only plain material but also weld deposit) under large cyclic deformation was investigated. As a result, a prediction equation for crack propagation under large deformation was proposed based on cyclic J-integral range. Besides, the proposed equation was verified through low cycle fatigue tests of corner welded joints.

Redistribution behavior of residual stress due to weld toe grinding Reviewed

Satoshi Maeda, Kazuo Tateishi, Takeshi Hanji, Masaru Shimizu

Proceedings of the ISSS 2015 page： 383-384 2015.11

Authorship：Lead author Language：English

Weld toe grinding is known to have relatively large variations in its improvement effects of fatigue strength. On the other hand, the residual stress distribution near the ground groove has not been revealed although it has a significant influence on the fatigue strength. In this research, X-ray stress measurements and finite element analyses were conducted in order to reveal the redistribution behavior of welding residual stress resulting from weld toe grinding.

Fatigue life prediction for cracked steel plates repaired with CFRP Reviewed

Mamiko Hattori, Takeshi Hanji, Kazuo Tateishi, Masaru Shimizu

Proceedings of the ISSS 2015 page： 377-378 2015.11

Authorship：Lead author Language：English

As a new repair method, Carbon-Fiber Reinforced Polymer (CFRP) adhesive repair has been getting attention. In this study, the effect of CFRP adhesive repair for a fatigue crack in a steel plate was investigated experimentally and analytically. The fatigue tests revealed that the propagation rate of a crack repaired with CFRP was reduced comparing with that without repair. Based on the results, a fatigue life prediction method for a crack with CFRP was proposed.

Analytical study on low cycle fatigue of shear panel in multiple steel columns Reviewed

Masaru Shimizu, Kazuo Tateishi, Takeshi Hanji, Riku Adachi

Proceedings of the ISSS 2015 page： 253-254 2015.11

Authorship：Lead author Language：English

Multiple Steel Columns can absorb seismic energy by shear deformation of shear panel. Due to large shear deformation in the shear panel, however, the low cycle fatigue crack could occur at the welding joint of shear panel. In this study, a cyclic loading test of Multiple Steel Columns was simulated by finite element analysis. Further, prediction method for crack initiation and propagation of low cycle fatigue in a welding joint of shear panel was developed.

Fatigue strength of welded joint with adjacent attachments Reviewed

Shunsuke Kase, Kazuo Tateishi, Takeshi Hanji, Masaru Shimizu

Proceedings of the ISSS 2015 page： 171-172 2015.11

Authorship：Lead author Language：English

In welded steel structures, there are some cases when weld-lines exist close to each other. As an example in steel highway bridges in Japan, a vertical stiffener is connected to a web plate close to an end of a horizontal stiffener. In this case, stress concentrations due to each joint may be superposed, and consequently, fatigue strength of the stiffeners may become lower compared with typical welded joints. In this study, fatigue tests and finite element analyses were performed on plate girders where vertical and horizontal stiffeners attached with a small gap between them. The result revealed that the stress concentration at the end of the horizontal stiffener slightly varied with the distance between the stiffeners, resulting in small difference of the fatigue strength.

Displacement based fatigue strength evaluation for root failure in fillet weld joints Reviewed

Kazuo Tateishi, Naohiro Souda, Takeshi Hanji, Masaru Shimizu

Journal of Structural Mechanics and Earthquake Engineering, JSCE Vol. 71 ( 3 ) page： 315-326 2015.9

Fatigue strength evaluation method of connection between longitudinal closed ribs and cross-beam web cutouts in orthotropic steel bridge decks Reviewed

Takeshi Hanji, Kazuo Tateishi, Keito Kato

Proceedings of the IABSE Conference Nara page： CD-ROM 2015.5

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

This study investigated fatigue strength evaluation methods based on the structural hot spot stress concept, focusing on a crack at a crossing between a longitudinal closed rib and a cross-beam (transverse rib) web cutout in an orthotropic steel bridge deck. The results indicated the possibility that the fatigue strength of the connection can be evaluated with the hot spot stress range. And also, it was revealed that the hot spot stress range hardly decreases with increasing of deck plate thickness and decreasing of transverse rib distance.

Crack propagation behaviour of structural steel in extremely low cycle fatigue region Reviewed

Nao Terao, Takeshi Hanji, Kazuo Tateishi

Proceedings of the IABSE Conference Nara page： CD-ROM 2015.5

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Extremely low cycle fatigue, which is caused by large cyclic deformation with small number of loading repetition, is one of the main failure modes in steel structures during earthquake. In this study, crack propagation behaviour of structural steel in extremely low cycle fatigue region was evaluated based on a non-linear fracture mechanics parameter calculated by analyses. The results demonstrated that crack propagation rate in extremely low cycle fatigue region can be estimated by using cyclic J-integral.

Simple repair method for fatigue cracks in welded joints by resin injection Reviewed

Mamiko Hattori, Takeshi Hanji, Kazuo Tateishi

Proceedings of the IABSE Conference Nara page： CD-ROM 2015.5

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

As a simple repair method for fatigue cracks in steel bridges, the resin injection method has been proposed. The method can decrease fatigue crack growth rate by injecting resin into a crack. In this study, the applicability of the method for cracks occurred by cyclic compressive loading was investigated by experiments and finite element analyses. The results revealed that the crack growth retardation can be expected even under the compressive loading when enough elastic modulus and infiltration of resin are achieved.

Extremely low cycle fatigue assessment of corner crack in concrete-filled steel piers based on effective notch strain approach Reviewed

Jin-Eun Park, Takeshi Hanji, Kazuo Tateishi

Journal of Structural Engineering, JSCE Vol. 61A page： 662-671 2015.3

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

This paper presents an assessment method for extremely low cycle fatigue cracks from corner joints in concrete-filled steel piers. Low cycle fatigue tests indicated that one of the main failure modes of concrete-filled steel piers are a fatigue crack from corner joints, which is caused by out-of-plane bending deformation of flange and web plates. In the previous study, authors had proposed extremely low cycle fatigue strength curves for the corner joints based on the effective notch strain approach. In this study, the proposed method was applied to the experiment of the concrete-filled piers and it is demonstrated that extremely low cycle fatigue life of the pier can be predicted by using the method.

DOI： 10.11532/structcivil.61A.662

Fatigue life extension by ICR treatment for cracked weld joints subjected to tensile or bending loads Reviewed

Kazuo Tateishi, Takeshi Hanji, Toshiyuki Ishikawa, Masaru Shimizu

Journal of Structural Engineering, JSCE Vol. 61A page： 627-637 2015.3

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

The impact crack closure retrofit treatment (called ICR treatment) is a technique to delay or arrest fatigue crack growth and enhance residual fatigue life of weld joints including a crack. The treatment is carried out with an air tool to peen plate near the crack and to produce plastic deformation of the steel surface in order to close crack opening. In this study, several fatigue tests on weld joints were conducted under tensile or bending loads in order to verify the life extension effect by ICR treatment. Besides, the effect of the loading types to the life extension was analytically investigated.

DOI： 10.11532/structcivil.61A.627

Local strain based low cycle fatigue strength evaluation method for deformed bars Reviewed

Takeshi Hanji, Kazuo Tateishi, Naoki Nagamatsu

Journal of Structural Engineering, JSCE Vol. 61A page： 767-776 2015.3

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

This study proposed a local strain based fatigue strength evaluation method for deformed bars in low cycle fatigue region. Fatigue tests were conducted with the bars which have different yield strength and transverse rib shapes. The results indicated that low cycle fatigue strength of the deformed bars is almost the same regardless of the yield strength but it depends on the rib shapes. This is because strain concentration at the rib changes due to its shape. Finally, this study demonstrated that the fatigue strength of the bars with different rib shapes can be uniquely evaluated by considering local strain at the rib.

DOI： 10.11532/structcivil.61A.767

A study on fatigue life improvement of weld joints by reducing residual stress Reviewed

Kazuo Tateishi, Takeshi Hanji

Journal of Constructional Steel Vol. 22 page： 795-800 2014.11

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

Reducing welding residual stress can improve fatigue strength of weld joints. Several techniques to reduce the welding residual stress have been developed and their benefits on fatigue strength have been confirmed by many fatigue tests. The test results also demonstrate that the benefit is influenced by mean stress and stress amplitude. In this study, with considering cyclic stress behavior at the cracking point, the influence of residual stress, the mean stress and the stress amplitude on fatigue strength improvement is discussed.

Low cycle fatigue assessments of corner welded joints based on local strain approach Reviewed

Takeshi Hanji, , Jin-Eun Park, Kazuo Tateishi

International Journal of Steel Structures Vol. 14 ( 3 ) page： 579-587 2014.10

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Low cycle fatigue strengths of corner welded joints with single bevel groove welding were studied. Low cycle fatigue tests were performed with three types of specimens which have different sizes of weld root face. The test results indicated that the low cycle fatigue strength of the corner welded joints strongly depends on the weld root size. Then, the fatigue strength of the corner joints was evaluated based on the effective notch strain at the weld root tip which was calculated by elasto-plastic finite element analyses. A unique relationship between the effective notch strain and the fatigue life of the joint was observed regardless of the weld root size. Therefore, it was revealed that the effective notch strain approach is applicable to evaluate the low cycle fatigue strength of the corner welded joints.

DOI： 10.1007/s13296-014-3015-8

Low cycle fatigue assessment for corner joints based on effective notch strain approach Reviewed

Takeshi Hanji, Jin-Eun Park, Kazuo Tateishi

The 67th Annual Assembly of International Institute of Welding page： XIII-2550-14 2014.7

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

One of the main failure modes of steel bridge piers is low cycle fatigue. In a concrete-filled steel pier with a box section, it has been reported that low cycle fatigue cracks are often initiated from longitudinal welds connecting flange and web plates (called corner joint) when it is subjected to large cyclic deformation. In this study, low cycle fatigue strengths of the corner joints were investigated. Low cycle fatigue tests were performed with corner joint specimens with different weld root sizes. Then, the fatigue strength of the corner joints was evaluated based on the effective notch strain at the root tip which was calculated by elasto-plastic finite element analyses. The results indicated a unique relationship between the effective notch strain range and the fatigue life of the joint regardless of the weld root size. Besides, the test results of the corner joints located in the same region as those of load-carrying cruciform joints. Therefore, it was demonstrated that the effective notch strain approach is applicable to evaluate the low cycle fatigue strength of welded joints regardless of the joint types.

Fatigue strength of overlap joint with transverse fillet weld subjected to out-of-plane bending Reviewed

Kazuo Tateishi, SungMin Choi, Takeshi Hanji, Daisuke Uchida, Koichi Asano, Kiyoshi Kobayashi

Steel Construction Engineering, JSSC Vol. 21 ( 81 ) page： 47-53 2014.3

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

Fatigue strength of overlap welded joints in which transverse fillet welds were provided was investigated under an out-of-plane bending condition. Fatigue test results demonstrated the joints were failed by weld toe cracks, and the fatigue strength was equal to that of non-load carrying cruciform joints. When intermittent fillet welds were provided, the fatigue strength was reduced, but it was properly evaluated by using the hot spot stress approach.

DOI： 10.11273/jssc.21.81_47

Fatigue strength of welded joints using steels for bridge high performance structures (SBHS) Reviewed

Takeshi Hanji, Kazuo Tateishi, Shuichi Ono, Yoshinori Danshita

Journal of Structural Engineering, JSCE Vol. 60A page： 587-595 2014.3

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

In this study, fatigue strength of welded joints using a newly developed steel called Steels for Bridge High Performance Structures (SBHS) was investigated.
Fatigue crack propagation tests with compact tension specimens were performed to clarify fatigue crack growth characteristic of materials. Then, fatigue strengths of welded joints using SBHS were investigated. These test results revealed that the fatigue performances of welded joints using SBHS are almost the same as those of conventional structural steels.

DOI： 10.11532/structcivil.60A.587

A study on size effect of fatigue strength of out-of-plane gusset welded joint Reviewed

Kengo Anami, Yusuke Goda, Daisuke Uchida, Shigeyuki Hirayama, Takeshi Hanji

Journal of Structural Engineering, JSCE Vol. 60A page： 651-660 2014.3

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

Fatigue strength category of out-of-plane gusset welded joint was determined based on large number of previous fatigue tests and is categorized with gusset length. However, the variety of the joint size of specimens used in previous researches is very limited and the size is much smaller than the joints in large structures like steel bridges. In this study, stress analyses with out-of-plane gusset welded joint models having large variety of joint size like from small joint specimen to joint in steel bridges were conducted and size effect on fatigue strength was discussed. In addition, the fatigue strength of joint having large out-of-plane gusset is analytically evaluated.

DOI： 10.11532/structcivil.60A.651

Fatigue strength improvement of weld joints with cope hole Reviewed

Sung-Min Choi, Kazuo Tateishi, Takeshi Hanji

International Journal of Steel Structures Vol. 13 ( 4 ) page： 683-690 2013.12

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Weld joint with a cope hole has relatively low fatigue strength, since high stress concentration is generated due to local shear deformation inside the cope hole. In this study, fatigue strength improvement for the cope hole joint by burr grinding is investigated. I-section beams with cope holes, of which boxing weld toes were smoothly finished by burr grinding, were tested and analyzed in order to know the fatigue strength and the local stress behavior of the joint. Test and analysis results demonstrated that the benefit of grinding on fatigue strength improvement is relatively small when shear stress is largely applied to the cope hole detail.

DOI： 10.1007/s13296-013-4009-7

Low cycle fatigue behavior of concrete filled steel bridge piers with box section Reviewed

Jin-Eun Park, Takeshi Hanji, Kazuo Tateishi

Journal of Constructional Steel Vol. 21 page： 802-808 2013.11

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Under seismic loadings, the main failure modes of steel bridge piers are local buckling and brittle fracture triggered by low cycle fatigue. In this study, the low cycle fatigue behavior of the steel pier in which concrete is filled for retrofitting against the local buckling was investigated experimentally and analytically. The low cycle fatigue tests on concrete filled steel pier specimens revealed that fatigue cracks occurring from corner welds caused final failure of the pier. Besides, strain behaviors around the cracking sites were revealed by elasto-plastic finite element analyses.

　 PREV - NEXT 　

<HANJI Takeshi>

Papers - HANJI Takeshi