Research on failure mode and load distribution pattern of composite pretightened tooth connections under different tooth shapes

Abstract

Currently, most studies on tooth shapes of composite pretightened tooth connections have focused on tooth connections with right-angle shape. Firstly, to investigate the influences of the tooth shape on the failure mode and bearing capacity of the joints, the single-tooth and multi-tooth specimens with different tooth shapes were studied by experiment. Secondly, a progressive damage mechanical model for composite joints was proposed. Finally, the mechanical properties of composite joints with different tooth shapes were studied through the proposed progressive failure model. The following results can be obtained. (1) The load displacement curve and failure process obtained by the numerical results are in good agreement with the experimental results, the correctness of the proposed progressive failure model can be proved. (2) The composite tooth shape had a fairly significant impact on the bearing capacity and failure mode of single-tooth joints. When the tooth angle varied from 30° to 90°, the specimens experienced shear failure, whereas when the tooth angle varied within the range of 7°–30°, the specimens suffered sliding failure. Bearing capacity of shear failure specimens was generally superior to that of sliding failure specimens. (3) The variation in composite tooth angle affected the internal force distribution pattern of multi-tooth joints. As the angle decreased, the second tooth replaced the first one as the maximum-load-bearing tooth, which mediated the originally nonuniform loading pattern of the teeth in the composite pretightened multi-tooth joint.