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Description
Aluminum alloy flange couplings are widely used in rotating machinery and power-transmission systems, but are almost always produced by sand casting, which inevitably introduces gas porosity, shrinkage porosity, and oxide bi-films. Although such defects are known to concentrate stress and initiate fatigue cracks, their effect on flange coupling life under combined axial-torsional loading has not been quantified. This study addresses that gap through an integrated framework combining solidification simulation, Finite element analysis (FEA), and continuum damage mechanics (CDM). Defect-free and defective 3D models of an A356/A357-T6 flange coupling were analyzed in ANSYS under nine combined axial force (10-30 kN) and torque (2-6 kN·m) cases at stress ratio R =0.1, followed by XFEM crack propagation analysis. Results show defects increase maximum von-Mises stress by 15-25% and reduce minimum fatigue life by 50-61%, with the severest case dropping life from 85,340 to 33,376 cycles (60.89% reduction).The damage model alone under-predicted this reduction, showing bulk damage and local stress concentration are both required to explain the fatigue behavior observed. This work provides a validated, cost-effective framework for assessing fatigue performance of sand-cast aluminum flange couplings.
| Topic Area | Fatigue, Corrosion and Structural Integrity of Engineering Structures and Mechanical Systems |
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