A new model for studying the kinetics of fatigue wear of a viscoelastic coating bonded to a rigid substrate is proposed. The fatigue mechanism is due to the cyclic interaction of the coating with a rough counterbody, which is modeled by a periodic system of smooth indenters. The study includes the solution of the problem of sliding contact of the indenter at a constant velocity along the viscoelastic coating, the calculation of stresses taking into account the mutual effect, and study of the process of damage accumulation in the material. The calculation of the damage function of the surface layer was carried out using the reduced stress criterion. Assuming the possibility of summation of accumulated damage, two processes were considered: delamination of surface layers of the coating and continuous fracture of the surface by the fatigue mechanism. The effect of the sliding velocity and viscoelastic properties of the material on the damage accumulation and the coating wear rate was analyzed. Two types of load, constant and stochastically varying, were used in modeling and analysis. It was found that the rate of fatigue wear of the coating increased and then became constant.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8585156 | PMC |
http://dx.doi.org/10.3390/ma14216513 | DOI Listing |
J Mech Behav Biomed Mater
January 2025
School of Materials Science and Engineering, Colorado State University, 700 Meridian Ave, Fort Collins, 80523, CO, USA. Electronic address:
Hyaluronic acid-enhanced polyethylene polymeric TAVR shows excellent in vivo anti-calcific, anti-thrombotic, and in vitro hydrodynamic performance. However, during durability testing, impact wear and fatigue cause early valve failure. Heart valve durability can be improved by strengthening the leaflet with fiber reinforcement.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China.
The abrasive wear performance of TiC particle-reinforced high-manganese steel matrix composites with a spherical hierarchical structure under moderate impact energy was investigated. In the composites, TiC particles (10 μm in diameter) were concentrated within discrete spherical composite regions with diameters of about 100 μm. Impact abrasive wear tests were conducted to evaluate the wear performance of the composites with different volume fractions (30%, 40%, and 50%) of TiC particles compared with the matrix and a uniformly distributed TiC particle composite.
View Article and Find Full Text PDFNat Commun
January 2025
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
Micro actuators are widely used in NEMS/MEMS for control and sensing. However, most are designed with suspended beams anchored at fixed points, causing two main issues: restricted actuated stroke and movement modes, and reduced lifespan due to fatigue from repeated beam deformation, contact wear and stiction. Here, we develop an electrostatic in-plane actuator leveraging structural superlubric sliding interfaces, characterized by zero wear, ultralow friction, and no fixed anchor.
View Article and Find Full Text PDFPurpose: Time-restricted eating (TRE) helps regulate rest-activity rhythms, blood glucose, and other diurnally regulated energetics processes, which may have implications for persistent fatigue. In a randomized controlled trial, we tested the effects of TRE vs. control on fatigue in cancer survivorship.
View Article and Find Full Text PDFAn Acad Bras Cienc
December 2024
Instituto Tecnológico de Aeronáutica (ITA), Departamento de Sistema Aeroespaciais, Pca. Mal. Eduardo Gomes, 50, 12228-900 São José dos Campos, SP, Brazil.
The transmission gearbox of military helicopters, such as the H225M, experiences intense dynamic loads, leading to the detachment of ferromagnetic particles, often due to wear or fatigue. This poses safety risks, as excessive particle detachment demands stringent maintenance. To address this, the study applies machine learning algorithms to predict particle detachment using data from the Flight Data Recorder and Health and Usage Monitoring System.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!