High-cycle fatigue of rotating cantilever round copper tube under load-controlled condition

[摘要] A cantilever rotating bending testing machine accepting only rod specimen with a fixed clamping diameter of 9 mm is modified for tube specimens using two developed adapters. One end of a φ15 mm copper tube is expanded into φ18 mm and forms the tube specimen. Two adapters fitting for φ15 mm and φ18 mm tube ends respectively are designed and fabricated. The φ15 mm adapter is connected to a shaft subject to an applied load and the φ18 mm adapter is connected to a motor, respectively through two collets. Both tube ends are adhered to the inner wall of the adapters with superglue to prevent slippery under the rotation. Finite element analysis is used to estimate the maximum applied stress in the tube specimen i.e. adjacent to the transition for a known counter weight. Only one fatigue test result i.e. at 2.2 × 106 cycles for applied stress of 205 MPa is successfully obtained from the experiment. The collets failed to clamp the adapters for applied stress higher or lower than 205 MPa due to the present of oxide powders resulting from the wear of the collect as it is a 15-year-old machine.

[发布机构] Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur; 50603, Malaysia^1

[效力级别] 工业技术 [学科分类] 工业工程学

[关键词] Applied loads;Applied stress;Controlled conditions;Copper tubes;High cycle fatigue;Oxide powder;Rotating bending;Under loads