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Two instrumented pulleys were developed to empirically measure the dynamic lateral forces of V-Ribbed belts used in automotive accessory drives. The first test pulley utilizes two cantilever beams cut into the pulley with strain gauges attached to measure the lateral dynamic forces in each individual belt rib caused by misalignment. A test stand which simulates multiple accessory drive configurations at low-end drive speeds typical in automotive engines was implemented to create the dynamic response necessary. This test stand allows variations in lateral offset, toe, camber, tension, and span length, as well as in the speed of the system through a variable speed AC motor. The second test pulley utilizes a unidirectional load cell oriented to measure the total lateral force on the test pulley. After conducting static calibration tests of the two experimental systems, dynamic results were obtained using real time data acquisition.

A three-dimensional V-Ribbed belt model was developed for use in the prediction of out of plane forces and displacements. A two dimensional model was first created to assist in developing the techniques needed to build the three dimensional model. A non-ribbed three-dimensional model was then developed to minimize the computer time needed to run the simulations. This belt model was used along with both frontside and backside pulleys to stretch the belt into position from its original round configuration. This model was also used for movement of the pulleys into or out of the belt plane, and toe and camber movements were applied to the pulleys. The knowledge gained from the first two models was then used to construct a program to generate the ribbed three-dimensional belt and pulleys. The models generated incorporated up to eight ribs and as many as nine pulleys in any model.

This paper investigates the effect of ambient temperature on the performance characteristics of an automotive poly-rib belt operating in an under-the-hood temperature environment. A three-dimensional dynamic finite element model consisting of a driver pulley, a driven pulley, and a complete V-ribbed belt was constructed. Belt tension and rotational speed were controlled by means of loading and boundary inputs. Belt construction accounts for three different elastomeric compounds and a single layer of helical wound reinforcing cord. Rubber was considered as hyperelastic material. Cord is linear elastic. The material model was implemented in ABAQUS/Explicit for the simulation. Analysis was focused on rib flank and tip since stress concentrations in these regions are known to contribute to crack initiation and fatigue failure.