Numerical analysis of the failure mechanisms of continuous miner's cutter sleeves for redesign and remanufacture

Traditional failure analysis employs visual and microscopic examinations to identify modes, causative factors, and mechanisms of component's damage. This approach is deficient in determining actual stresses and deformation which cause component's failure; analysing how component's geometry influence its failure; and assessing the feasibility of the recommended remedial measures to mitigate component's failure. To address these concerns in failed sleeves of continuous miner's cutter (CMCs); this study employed ANSYS software for finite element analysis (FEA), analytical calculation for model verification, while simulation findings were validated via microscopic observations. Collar fracture resulted from a high stress concentration (above 200 MPa) along the transition fillet areas while plastic deformation was caused by stresses above 100 MPa. Interactions between the sleeve and the rock seam generated cyclic stresses between 17–25 MPa which caused collar wear. Geometrical redesign of the sleeve collar by increasing fillet radius from 1 to 9 mm reduced stress to 133.03 MPa due to lower stress concentration factor. Surface modification with hybrid composite (TiC10%wt-WC10%wt) exhibited the best wear-resistance experimentally with the stress reduced to 6.8 MPa upon impact. Simultaneous combination of geometrical redesign and surface modification of the sleeve via laser cladding reduced deformation by 16.53 % (from 0.01277 mm to 0.010658 mm) and stress from 379.78 MPa to 116.44 MPa. It is concluded that multi-faceted failure analysis is a comprehensive approach that not only uncovers the failure modes, causes and mechanisms of premature failure of rotary sleeves, but also ascertains the causative stresses and remedial measures to mitigate the failure of CMC's sleeves.