Effect Of Overload On Permanent Elongation Deformation Of Mining Round-link Chain

The failure by round-link chain is more than half in the scraper conveyor failure in coalmine production. The permanent elongation deformation is one of the main failures in thescraper chain, and the overload of traction chains of scraper conveyor in active service wouldbe induce the permanent elongation deformation of mining round-link chain. As so far, thepermanent elongation deformation of round-link chain research mainly focused on the residualplastic length measurement methods of round-link chain and measurement tools and so on,while the analysis on the residual stress-strain and the permanent elongation deformation ofround-link chain under different load is less. Because the permanent elongation deformation ofround-link chain has important influence on reducing the failure caused by the round-linkchain, the permanent elongation deformation of round-link chain is analyzed in thisdissertation. Main research works performed are as follows:(1) By using elastic-plastic finite element software ABAQUS, the effect of the differentloads on the permanent elongation deformation of the round-link chain is analyzed. Theinvestigated results provide the permanent elongation deformation of the round-link chainswill beyond the state coal mine safety regulation of the round-link chains replacement standardin more than93%of the normal workload.(2) Through calculating the permanent elongation deformation of round-link chain underdifferent parameters (such as yield stress and tangent modulus, elastic modulus and geometrysize), the differences of the permanent elongation deformation of round-link chain under thedifferent yield stress, tangent modulus, elastic modulus and geometry size is analyzed, it isconcluded that the influence of geometry size and yield stress on the permanent elongationdeformation of round-link chain is bigger, the influence of tangent modulus and elasticmodulus on the permanent elongation deformation of round-link chain is smaller.(3) The round-link chain permanent elongation deformation of the secondaryover-loading is calculated and analyzed, it is found that the effect of the secondary over-loading than the once over-loading on the permanent elongation deformation ofround-link chain is small due to the strain-hardening of the material.