| This dissertation, consisting of three parts, investigates the operation and failure of automotive accessory serpentine belt using finite element analysis. In part I, a poly-rib belt finite element model was created using ABAQUS to simulate the operation of a two-pulley belt drive system. A tangential shear angle and an axial shear angle were defined to quantify the shear deformations of the ribs. The non-uniform contact stress distribution across belt cross section and the speed variation along belt-pulley contact arc were found to be closely related to the shear deformations. The high service temperature effect was also discussed. In part II, a general finite element model for crack in rubber solid was created using ABAQUS and used along with a newly developed neural network based hyperelastic material model to compute the J-integrals. The J-integrals evaluated numerically were in close agreement to the available results in literature and the J-integrals determined with multi-specimen rubber fracture experiments. The critical loads for crack initiation predicted with the crack model correlated very well with the experimental results. In part III, a global-local finite element analysis of belt failure was conducted by combining a relatively coarse global belt finite element model and a refined finite element model for belt rib crack. A global three-pulley belt system model was used to obtain the displacement and stress results, and to identify the most critical location for a mode-I through-the-thickness crack in belt rib. A three-dimensional local finite element model of a small segment of rib containing a crack, driven by the global model, was used to compute the J-integral. The J-integral for rib crack was found to be very sensitive to backside pulley operation and pre-crack length and less sensitive to pulley pre-load. |
