Article
Engineering, Mechanical
Srikakulapu Kiranbabu, Lutz Morsdorf, Ivan Gonzalez, Michael Koelling, Christian Bross, Dirk Ponge, Michael Herbig, David Mayweg
Summary: This study investigates the causes of white etching cracks (WECs) in wind turbine gearbox (WTGB) bearings. The results show that the presence of MnS inclusions is a key factor in the initiation of WECs in WTGB bearings.
Article
Engineering, Mechanical
Lanwen Wang, Xuanyu Sheng, Zhimeng Yao, Jianbin Luo
Summary: A coupled mechanical-diffusion peridynamic(PD) fatigue model is proposed to simulate hydrogen-assisted white etching cracks in bearing steel under rolling contact fatigue. The PD model of microstructural alteration based on the dislocation-assisted carbon migration theory is used to simulate the formation of dark etching region and white etching area, and its validity is demonstrated by experimental observations. The PD stress-assisted diffusion model is utilized to simulate the diffusion of hydrogen, and then the polycrystalline fatigue simulation is implemented to analyze the evolution of hydrogen-assisted white etching cracks. The effects of contact conditions and internal inclusions on the evolution of white etching cracks are also discussed in this study.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Yun-Shuai Su, Shu-Xin Li, Feng Yu, Si-Yuan Lu, Yong-Gang Wang
Summary: This study explores the common origin of the shear band (SB) and white etching area (WEA) in bearing steel under shear plastic deformation, revealing that they can both be considered as shear localization under large plastic deformation. The study compares the microstructures of SB and WEA, providing new insights into the origin and formation mechanism of WEA, and enhancing the understanding of bearing failure under rolling contact fatigue.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Construction & Building Technology
Yajun Zhang, Fei Yang, Yun Sun, Qiang Zhou, Yuqing Liu
Summary: This paper presents an experimental and numerical study on the bearing strength and failure modes of single-bolt connections. A finite element modeling method considering tensile and shear material properties accurately predicts the whole process behavior of the connections. The TEH model and ASIC specification accurately predict the failure modes and bearing strength of single-bolt connections.
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
(2023)
Article
Chemistry, Analytical
Viorel Goanta
Summary: This paper presents a simple and reliable device for torsional fatigue testing, adaptable to a universal pulsating testing machine, for determining the torsion fatigue limit of different materials. It also introduces an experimental method for determining shear strains, comparing values obtained from a calibration experiment with those from theoretical calculation.
Article
Construction & Building Technology
Yu Zhang, Kaifeng Zheng, Jin Zhu, Ming Lei, Xiaoyang Feng
Summary: Weathering steel and high-performance steel are commonly used in bridge engineering, but corrosion effects can reduce their fatigue strength, posing a threat to the safety and reliability of bridges. Experimental results show that corrosion causes a decrease in the fatigue strength of Q345CNH and HPS 70 W, with fatigue cracks primarily originating from pitting flaws.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Shuai Liu, Danping Gao, Bowang Chen
Summary: This study experimentally investigated the connection of a Steel-Bamboo Composite structure and discussed the effects of diameter, spacing, and type of shear connectors on its mechanical properties. An optimized design for the connectors was proposed, along with an equation for the shear bearing capacity of the composite structure.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Engineering, Mechanical
Xiangqiao Yan
Summary: The empirical fracture equation for mixed mode crack proposed in this note has been verified to be simple in computation and high in accuracy based on test data from literature.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
Daniel Gren, Knut Andreas Meyer
Summary: Rolling contact loading can cause plastic deformation and fatigue cracks. Current rail standards do not consider the effect of plasticity on mechanical behavior. This study proposes a new method for evaluating the fatigue life of deformed material and finds that superimposed compressive axial loads can increase fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Mael Zaid, Vincent Bonnand, Veronique Doquet, Vincent Chiaruttini, Didier Pacou, Pierre Depouhon
Summary: In this study, mode II fatigue crack growth under reversed shear and static biaxial compression was investigated in two bearing steels. The presence of aborted branches and the influence of compressive stress parallel to the main crack on crack growth were observed.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Chemistry, Multidisciplinary
Guangyuan Wang, Yuhua Li, Jingyun Chen, Yiren Sun, Weiying Wang, Yongjun Liu
Summary: A new shear testing device is developed to investigate the shear behavior of asphalt mixture. The paper analyzes the stress state and failure criterion of the mixture under torsional load in different compression conditions using mechanical theory. The size and experimental plan of the specimen are explained, and two types of shear tests are conducted using the testing apparatus. The results highlight the importance of temperature, loading speed, and normal stress levels in torsional shear testing.
APPLIED SCIENCES-BASEL
(2022)
Article
Polymer Science
Hiroshi Yoshihara, Momoka Wakahara, Masahiro Yoshinobu, Makoto Maruta
Summary: This study determined the in-plane and out-of-plane shear moduli of XPS through torsional vibration tests and compared them with results from flexural vibration tests. The torsional vibration tests accurately measured the shear moduli with less dependence on sample width. Performing a range of torsional vibration tests is recommended for accurate measurement of both in-plane and out-of-plane shear moduli of XPS.
Article
Nanoscience & Nanotechnology
Z. K. Xu, B. Wang, P. Zhang, X. Z. Gu, Z. F. Zhang
Summary: The high-cycle torsional fatigue crack propagation behaviors of martensitic AISI 4340 steel were studied in this research. Quantitative analyses were conducted to investigate the branching mechanisms in the early stage and deflection characteristics in the later stage of crack propagation. It was observed that when the mode I stress intensity factor exceeded the threshold value K-I,K-th, the initial crack would split into four mode I cracks. Moreover, different pairs of branches had a competitive relationship. The backward pair of branches faced more boundary barriers and their driving force was reduced by the stress redistribution caused by the leading pair of branches. Additionally, the crack gradually transitioned from mode I to mode II due to grip restrictions. When K-II/K-I > 1.5, the crack growth became complete mode II.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Engineering, Civil
Hirofumi Toyota, Susumu Takada
Summary: This study evaluated ground settlement induced by cyclic stress using a hollow cylindrical torsional shear apparatus considering a moving load, which mimics a certain traffic loading condition. Results highlighted the importance of analyzing combined stresses and demonstrated relations among vertical strain, the magnitude of loading, and sand density based on experimentally obtained results.
TRANSPORTATION GEOTECHNICS
(2021)
Article
Engineering, Civil
Elif Boru
Summary: The contribution of glass fiber reinforced polymers (GFRP) to the torsional behaviour of steel I beams was investigated through experimental and numerical studies. Different GFRP configurations and surface roughness were tested, and it was found that strengthening with diagonal GFRP strips and increasing surface roughness had the greatest impact on torsional behaviour. This study provides valuable insights into improving the torsional strength of steel I beams using GFRP reinforcement.
