Article
Engineering, Mechanical
Xing Du, Longyong Wu, Jiacheng Miao, Xiaobing Li, Zhixin Shi, Bingkui Chen
Summary: In this paper, the authors decompose the surface waviness in the helical direction into circumferential and axial surface waviness, and propose a time-varying contact model considering the nonuniform surface waviness to investigate the time-varying contact characteristics of the planetary roller screw mechanism. The effects of the surface waviness of the screw, roller, and nut thread raceway on the axial clearance and contact force are analyzed, and the results show that these parameters are time-varying rather than time-invariant.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Vieroslav Molnar, Gabriel Fedorko, Beata Stehlikova, Peter Michalik
Summary: The missing roller in a hexagonal idler housing of a hose conveyor is often underestimated but can have serious consequences, mainly affecting the conveyor belt or individual components. Identifying this type of failure early is challenging, but measuring force ratios can be a helpful method. Experimental measurements have shown a strong dependence between force ratios and a missing roller, allowing for more accurate identification of this type of failure in a hose conveyor.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Multidisciplinary
Zhifeng Shi, Jing Liu
Summary: Collisions between a roller and its cage can cause crack initiation and propagation, resulting in the fracture of the cage bridge. The strain distribution of the cage is influenced by the impact forces applied to a needle roller-bearing cage bridge, which is related to the relative speed of the roller and cage. This study constructed a needle roller-bearing roller-cage impact test rig to measure cage strain and investigate the effects of speed on roller-cage impact forces.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Xueqin Hou, Qing Diao, Yujian Liu, Changkui Liu, Zheng Zhang, Chunhu Tao
Summary: In this study, the failure cause of a cylindrical roller bearing was analyzed using various methods. The results showed that excessive load caused the bearing failure. The failure mechanism was the deformation and cylindricity increase of the inner ring raceway induced by excessive tightening axial force, resulting in high local contact stress and bearing failure.
Article
Chemistry, Analytical
Fanyu Zhang, Hangyuan Lv, Qingkai Han, Mingqi Li
Summary: Double-row tapered roller bearings have gained wide application in various equipment due to their compact structure and high load-bearing capacity. However, there have been few studies on the contact stiffness of these bearings. This research establishes a contact mechanics calculation model for double-row tapered roller bearings under composite loads, and analyzes the influence of load distribution on the bearing. The effects of different working conditions on the contact stiffness of the bearing are simulated and analyzed, revealing the impact of various factors. The research provides theoretical support for the design and performance identification of double-row tapered roller bearings under complex loads.
Article
Multidisciplinary Sciences
Joachim Gwinner
Summary: This note presents a novel frictional unilateral contact problem in finite-strain elasticity and analyzes it using the polyconvexity approach to nonlinear elasticity. The author also proposes a smoothing procedure for tackling the non-smooth term in friction and provides a convergence result for this new method.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Computer Science, Artificial Intelligence
Hassen Louati, Slim Bechikh, Ali Louati, Chih-Cheng Hung, Lamjed Ben Said
Summary: This paper discusses the current status and challenges of CNN architecture design, proposing to tackle it as a bi-level optimization problem. By using the improved evolutionary algorithm BLOP-CNN, optimized architectures were obtained, showing superior performance in image classification tasks and COVID-19 detection.
Article
Engineering, Mechanical
Sivakumar Kanniyappan, Mallina Venkata Timmaraju, Gnanamoorthy Rajappa
Summary: This study investigated the dynamic mechanical behavior of short fiber reinforced polyamide 66 composite sprocket-roller chain drive. The variations in chain pitch affected the contact behavior and peak force of the driver sprocket. Increasing the pretension force of the roller chain further enhanced the contact force of the driver sprocket.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2022)
Article
Computer Science, Information Systems
Shinichi Masaoka, Yuki Funabora, Shinji Doki
Summary: This study presents a wearable assistive robot that directly measures the contact force between the robot and the human body, aiming to enhance safety. Two experiments were conducted to verify the contact force measurement performance and demonstrate the application of contact force information for safety evaluation. The proposed robot accurately measures contact force and ensures safe movement under general control.
Article
Chemistry, Analytical
Vijay Kakani, Xuenan Cui, Mingjie Ma, Hakil Kim
Summary: This paper presents the development of a vision-based tactile sensor system that uses neural networks to estimate tactile contact position, area, and force distribution. The system involves training the network with input loads at various motions and collecting output data for validation through experiments with different shapes and sizes of tactile sensors.
Article
Chemistry, Multidisciplinary
Zhewei Huang, Sulin Chen, Qiang Lin, Zhe Ji, Peng Gong, Zhengzong Sun, Bin Shen
Summary: Wrinkles are commonly found on the surface of graphene, leading to increased friction and lubrication degradation. Through nanoscratch tests and molecular dynamics simulations, the mechanisms underlying the friction evolution of wrinkles are revealed.
Article
Engineering, Chemical
Zhihong Nie, Qun Qi, Xiang Wang, Yangui Zhu
Summary: The study used discrete element method to simulate the cyclic loading of gravel-sand mixtures with low fines contents, finding that increasing fines content accelerated the development of strain but had little effect on contact forces evolution. Strong contacts tended to develop along loading boundary with spatial differences, while weak contacts were initially controlled by confining pressure and then by axial stress.
Article
Engineering, Mechanical
Yuwei Liu, Xingyu Fan, Jia Wang, Xiayi Liu
Summary: This study investigates the effects of the geometric homogeneity of rollers on the friction torque of tapered roller bearings (TRBs). The results show that while the geometric homogeneity of the rollers has minimal influence on the overall friction torque, it significantly increases the slide friction force between the individual rollers and the inner raceway. Furthermore, the diameter deviation value of the roller has a significant impact on the maximum sliding friction, especially under light load conditions.
Article
Engineering, Biomedical
Grant James Dickey, Kewei Bian, Sakib Ul Islam, Habib R. Khan, Stephan Rohr, Haojie Mao
Summary: This study used finite element models and simulated baseball collisions to investigate the risk of Commotio cordis in different age groups and impact conditions. The results showed correlations between left ventricular strain and pressure, chest band and rib deformation, and force of impact. Future revisions to Commotio cordis safety requirements should consider including deformation-related risk metrics at the level of the left ventricle.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Mechanics
Jing Chang, Zhong Luo, Yunlei Wang, Qingkai Han, Fangjun Han, Hongwei Zhang
Summary: This paper focuses on characterizing the contact model of the variable stator vane (VSV) mechanism, considering the dry friction properties of joint materials. Experimental tests are conducted to determine the important parameters of the contact model, which are then used in the dynamic analysis of a VSV mechanism test rig. The accuracy of the contact model is verified through simulation and compared with other macro models.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2023)
Article
Engineering, Ocean
Canjun Yang, Dingze Wu, Puzhe Zhou, Shuyang Ma, Rui Zhou, Xin Zhang, Yang Zhang, Qingchao Xia, Zeliang Wu
Summary: The Argo Global Ocean Observing Network is the preeminent ocean observation network worldwide, but its buoys fail to complete long-term observations in designated sea areas due to their lack of lateral movement. To solve this problem, a portable underwater profiler (PUP) that combines buoy and underwater glider functionalities was developed. The PUP is lightweight, allows for rapid deployment, and enables continuous observation.
APPLIED OCEAN RESEARCH
(2024)
Article
Engineering, Ocean
Knut Andreas Kvale, Bernt Leira, Ole Oiseth
Summary: As future floating bridges become longer, the chance of encountering significant inhomogeneous wave conditions increases. This paper presents an approach to model these conditions using generalized harmonic decomposition and applies it to a conceptual floating bridge model in Norway. The paper focuses on frequency-domain simulation and highlights the importance of considering the coherency in swell sea conditions.
APPLIED OCEAN RESEARCH
(2024)