Faculty Profiles - SHIMIZU Masaru

Study on unsymmetrical steel gable frames constructed from built up columns and rafters

Panjaitan A., Hasibuan P., Shimizu M.

Aip Conference Proceedings Vol. 2711 2023.5

Publisher：Aip Conference Proceedings

Steel gable frames is a structure type widely used for warehousing. Such structure is characterized by the long span roof truss and minimum number of columns to optimaze storage capacity. A gable frame is commonly composed by single profile of rafter and column to ensure the compactness of sectional area. However, in many cases, the capacity of single profile cannot be met and a gable frame has to be established from built up profile sections. This paper analytically investigated a design of gable frame constructed from built up profiles with considering unsymmetrical slopes in rafter. Three different unsymmetrical steel gable frames (SGF) with different rafter slope at the left and right side were provided. For each model, the left rafter has gentler slope than the right rafter. The models were named according to the left rafter slope: SGF 10 (10-degree slope), SGF 20 (20-degree slope), and SGF 30 (30-degree slope), respectively. First, the model of gable was established and load combinations were applied. The internal forces obtained from analysis were used to design the gable frames. The design referred to SNI-1729-2020. This study revealed that SGF 30 experienced the lowest internal forces and resulted the smallest sectional area for rafters and columns. Furthermore, torsional effects were also negligible in all steel gable frames. Investigation on three gable frames indicated that SGF 30 which has the steeper slopes exhibited the best performance than the SGF 10 and SGF 20.

DOI： 10.1063/5.0137293

鋼橋ソールプレート溶接部の発生応力推定に関する解析的検討 Reviewed Open Access

丹羽雄一郎, 舘石和雄, 判治剛, 清水優

構造工学論文集A Vol. 69A page： 568 - 578 2023.4

Analytical study on estimation of stress generated in sole plate welds of steel bridges Reviewed Open Access

Niwa Yuuichirou, Tateishi Kazuo, Hanji Takeshi, Shimizu Masaru

Journal of Structural Engineering, A Vol. 69A ( 0 ) page： 568 - 578 2023.4

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers

In this study, a screening method for the fatigue cracks around the sole plate welds in preventive maintenance was studied based on measurements of the actual bridge and finite element analysis. First, the results of the actual bridge measurements show that the compressive stress at the lower surface of the lower flange increases as closer to the sole plate welds. Next, by parametric study with plate thickness, it was shown that the hot-spot stress range at the front fillet weld toe between the lower flange and sole plate can be estimated by the local cross-sectional area and the horizontal reaction force. Based on the results, a formula for the hot-spot stress range at the front fillet weld toe between the lower flange and sole plate was proposed to screen locations at high risk against fatigue.

DOI： 10.11532/structcivil.69A.568

Fatigue Crack Growth Characteristics of Several Kinds of Structural Steels Under Low-Cycle Fatigue Loading Reviewed International coauthorship

Jiang Chao, Hanji Takeshi, Tateishi Kazuo, Shimizu Masaru

INTERNATIONAL JOURNAL OF STEEL STRUCTURES Vol. 23 ( 1 ) page： 37 - 49 2023.2

既設鋼床版のUリブ・デッキプレート溶接部に対する床版下面からの疲労対策 Reviewed Open Access

服部雅史, 舘石和雄, 判治剛, 清水優

土木学会論文集 Vol. 79 ( 1 ) page： 1 - 20 2023.1

FATIGUE COUNTERMEASURES FOR U-RIB TO DECK WELDED JOINTS FROM UNDERSIDE OF EXISTING ORTHOTROPIC STEEL DECKS Reviewed Open Access

HATTORI Masafumi, TATEISHI Kazuo, HANJI Takeshi, SHIMIZU Masaru

Japanese Journal of JSCE Vol. 79 ( 1 ) page： 1 - 20 2023.1

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers

This paper proposes a countermeasure for fatigue cracks that propagate from the weld root of U-rib to deck welded joints to the deck plate or weld bead of orthotropic steel deck. Specifically, the lower flange of the U-rib is removed and the U-rib and deck plate welds are welded from the inside of the U-rib as a countermeasure method. First, to confirm the feasibility of this countermeasure with structural changes, the load-bearing capacity, workability of welding, and effects on asphalt pavement were verified. Next, changes in the local stress properties of the focused welds and other areas due to the countermeasures were confirmed by finite element analysis. Finally, the fatigue durability of the countermeasure was determined by fatigue tests.

DOI： 10.2208/jscejj.22-00231

Fatigue evaluation for root cracks in U-rib to deck welded joints of orthotropic steel decks

Hattori M., Tateishi K., Hanji T., Shimizu M.

Bridge Safety Maintenance Management Life Cycle Resilience and Sustainability Proceedings of the 11th International Conference on Bridge Maintenance Safety and Management Iabmas 2022 page： 2123 - 2130 2023

Publisher：Bridge Safety Maintenance Management Life Cycle Resilience and Sustainability Proceedings of the 11th International Conference on Bridge Maintenance Safety and Management Iabmas 2022

This paper examines a fatigue evaluation method for the cracks in the weld joints between a U-rib and a deck plate in orthotropic steel bridge decks. The crack initiates from the weld root and propagates into the deck plate or the weld bead. Fatigue tests and FE analyses were conducted in order to examine the local stresses available for fatigue assessment, and to propose a method to estimate them from some reference stresses around the weld joint. In addition, based on fatigue crack propagation analyses, a method to predict the crack propagation path was proposed.

DOI： 10.1201/9781003322641-263

Numerical investigation of fatigue crack propagation behavior in trough-girder bridges Open Access

Putra Teuku Habil, Hanji Takeshi, Tateishi Kazuo, Shimizu Masaru, Yamaguchi Makoto, Niwa Yuuichirou

Journal of Structural Engineering, A Vol. 69A ( 0 ) page： 558 - 567 2023

Language：English Publisher：Japan Society of Civil Engineers

Fatigue cracks have been observed from welded joints of end diaphragms at steel railway troughgirder bridges due to vertical movement behavior at their supports that is not expected during the design phase. Since this movement behavior is complicated and varies on each bridge depending on the damage around the support, effective retrofitting methods against the crack have not been established yet. In this study, the influence of the vertical movement tendency at the bridge supports on the crack initiation location and crack propagation behavior at the end diaphragm was investigated through numerical simulation. The result indicated that the relative displacement at the bedplate affected the crack initiation location and crack propagation path, and that the stress intensity factor tended to gradually decrease after propagating a certain length.

DOI： 10.11532/structcivil.69a.558

Fatigue strength enhancement of welded joints in existing steel bridges using high-frequency mechanical impact treatment

Prediction of Residual Stress Induced by High-Frequency Mechanical Impact (HFMI) Treatment

HANJI Takeshi, MASUI Shunsuke, TATEISHI Kazuo, SHIMIZU Masaru, ONO Shuichi

Preprints of the National Meeting of JWS Vol. 2023s ( 0 ) page： 180 - 181 2023

Hanji T., Tateishi K., Kano S., Shimizu M.

Publisher：Bridge Safety Maintenance Management Life Cycle Resilience and Sustainability Proceedings of the 11th International Conference on Bridge Maintenance Safety and Management Iabmas 2022

In this study, the effect of the stress state of a welded joint during application of high-frequency mechanical impact (HFMI) treatment on the resulting fatigue strength was investigated through fatigue tests and finite element analysis. A high-frequency impact treatment tool was used as the HFMI device. Longitudinal attachment welded joints were treated under a state in which a static load was applied and subsequently tested under a constant stress amplitude with stress ratios of 0 or 0.5. In addition, residual stress measurements and finite element analysis simulating welding and treatment processes were performed. The results indicate that the HFMI treatment is beneficial even when applied under a static tensile load, as the resulting compressive residual stresses are similar regardless of the stress state in the joint during treatment, meaning that the HFMI is applicable to existing structures.

DOI： 10.1201/9781003322641-262

Effect of UHPFRC Overlay on Fatigue Cracks Propagating from U-rib Welds of Orthotropic Steel Decks Reviewed

Hattori Masafumi, Tateishi Kazuo, Hanji Takeshi, Shimizu Masaru

INTERNATIONAL JOURNAL OF STEEL STRUCTURES Vol. 22 ( 6 ) page： 1808 - 1816 2022.12

Fatigue Strength of Deck-to-Rib Welded Joint And Correlation to Full-Scale Orthotropic Steel Deck System Reviewed

Masaru SHIMIZU, Takayuki UCHIDA, Kazuo TATEISHI, Takeshi HANJI, Masafumi HATTORI

Vol. 30 page： 297 - 305 2022.11

Fatigue Strength of Deck-to-Rib Welded Joint And Correlation to Full-Scale Orthotropic Steel Deck System Reviewed

Masaru SHIMIZU, Takayuki UCHIDA, Kazuo TATEISHI, Takeshi HANJI, Masafumi HATTORI

Vol. 30 page： 297 - 305 2022.11

コーナープレート切欠き部の疲労耐久性とICR処理による延命効果 Reviewed Open Access

清水優, 舘石和雄, Shinta Ayuningtyas, 判治剛, 高田佳彦, 熊澤美早, 山口樹, 岡本亮二, 西芝貴光

構造工学論文集 Vol. 68A page： 580 - 590 2022.4

Fatigue durability of cut-out in corner plate and fatigue life extension by ICR treatment Reviewed Open Access

Shimizu Masaru, Tateishi Kazuo, Ayuningtyas Shinta, Hanji Takeshi, Takada Yoshihiko, Kumazawa Misa, Yamaguchi Itsuki, Okamoto Ryoji, Nishishiba Takamitsu

Journal of Structural Engineering, A Vol. 68A ( 0 ) page： 580 - 590 2022.4

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers

Corner plates are often welded at the intersection between web and flange in steel box girders. As a measure against fatigue in the weld joint between corner plate and lateral rib, the end of corner plate was cut-out in U-shape. Nevertheless, fatigue cracks have been generated from exposed root on the cut-out surface. In this study, fatigue strength and fatigue life improvement by ICR treatment were investigated. The fatigue strength of the weld joint was JSSC-G class. Application of ICR treatment improves the fatigue strength by 1 grade or more, and the fatigue limit was improved as 59 N/mm2 or more. Furthermore, stress concentration factor around exposed root was investigated by finite element analysis.

DOI： 10.11532/structcivil.68A.580