{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,18]],"date-time":"2025-10-18T00:09:25Z","timestamp":1760746165787,"version":"build-2065373602"},"reference-count":25,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,15]],"date-time":"2025-10-15T00:00:00Z","timestamp":1760486400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["52574194"],"award-info":[{"award-number":["52574194"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Open Project of the National Engineering Laboratory for Coal Mining Machinery"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Computation"],"abstract":"<jats:p>This study investigates premature fatigue failure in rocker arm gears of large-mining-height shearers operating at alternating \u00b145\u00b0 working angles, where insufficient lubrication generates non-uniform thermal -stress fields. In this study, an integrated multiphysics framework combining transient thermal\u2013fluid\u2013structure coupling simulations with fatigue life prediction is proposed. Transient thermo-mechanical coupling analysis simulated dry friction conditions, capturing temperature and stress fields under varying speeds. Fluid\u2013thermal\u2013solid coupling analysis modeled wet lubrication scenarios, incorporating multiphase flow to track oil distribution, and calculated convective heat transfer coefficients at different immersion depths (25%, 50%, 75%). These coupled simulations provided the critical time-varying temperature and thermal stress distributions acting on the gears (Z6 and Z7). Subsequently, these simulated thermo-mechanical loads were directly imported into ANSYS 2024R1 nCode DesignLife to perform fatigue life prediction. Simulations demonstrate that dry friction induces extreme operating conditions, with Z6 gear temperatures reaching over 800 \u00b0C and thermal stresses peaking at 803.86 MPa under 900 rpm, both escalating linearly with rotational speed. Lubrication depth critically regulates heat dissipation, where 50% oil immersion optimizes convective heat transfer at 8880 W\/m2\u00b7K for Z6 and 11,300 W\/m2\u00b7K for Z7, while 25% immersion exacerbates thermal gradients. Fatigue life exhibits an inverse relationship with speed but improves significantly with cooling. Z6 sustains a lower lifespan, exemplified by 25+ days at 900 rpm without cooling versus 50+ days for Z7, attributable to higher stress concentrations. Based on the multiphysics analysis results, two physics-informed engineering optimizations are proposed to reduce thermal stress and extend gear fatigue life: a staged cooling system using spiral copper tubes and an intelligent lubrication strategy with gear-pump-driven dynamic oil supply and thermal feedback control. These strategies collectively enhance gear longevity, validated via multiphysics-driven topology optimization.<\/jats:p>","DOI":"10.3390\/computation13100242","type":"journal-article","created":{"date-parts":[[2025,10,15]],"date-time":"2025-10-15T06:06:32Z","timestamp":1760508392000},"page":"242","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Multiphysics Framework for Fatigue Life Prediction and Optimization of Rocker Arm Gears in a Large-Mining-Height Shearer"],"prefix":"10.3390","volume":"13","author":[{"given":"Chunxiang","family":"Shi","sequence":"first","affiliation":[{"name":"China Coal Technology & Engineering Group Shanghai Co., Ltd., Shanghai 200030, China"}]},{"given":"Xiangkun","family":"Song","sequence":"additional","affiliation":[{"name":"China Coal Technology & Engineering Group Shanghai Co., Ltd., Shanghai 200030, China"}]},{"given":"Weipeng","family":"Xu","sequence":"additional","affiliation":[{"name":"China Coal Technology & Engineering Group Shanghai Co., Ltd., Shanghai 200030, China"}]},{"given":"Ying","family":"Tian","sequence":"additional","affiliation":[{"name":"College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China"},{"name":"Shandong Key Laboratory of Collaborative Mining Technology for Intelligent Mine Equipment, Qingdao 266590, China"}]},{"given":"Jinchuan","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China"},{"name":"Shandong Key Laboratory of Collaborative Mining Technology for Intelligent Mine Equipment, Qingdao 266590, China"}]},{"given":"Xiangwei","family":"Dong","sequence":"additional","affiliation":[{"name":"College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China"},{"name":"Shandong Key Laboratory of Collaborative Mining Technology for Intelligent Mine Equipment, Qingdao 266590, China"}]},{"given":"Qiang","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China"},{"name":"Shandong Key Laboratory of Collaborative Mining Technology for Intelligent Mine Equipment, Qingdao 266590, China"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Cao, X., Xu, W., Zhao, J., Dusn, Y., and Yang, X. 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