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The objective of this paper is to develop a comprehensive non-linear finite element model for determining failure behavior of hydrogen composite storage cylinders subjected to high pressure and flame impingements. A resin decomposition model is implemented to predict the residual resin content. A material degradation model is used to account for the loss of moduli. A failure model based on Hashin's failure theory is implemented to detect various types of composite failure. These sub-models are implemented in ABAQUS finite element code using user subroutine. Numerical results are presented for thermal damage, residual properties and resin content.

The use of a predictive fatigue crack growth model to monitor progressive deterioration of initially small rib-tip flaws in automotive serpentine belts is presented in this paper. Model is based on computational fracture mechanics and fatigue coupon test data. A global-local finite element analysis procedure is used to compute the J-integral for a through-the-thickness crack in the rib tip. The three-dimensional global model is created with relatively coarse mesh using first order continuum elements in ABAQUS. The local model rib crack is constructed with significantly finer mesh utilizing second order continuum elements. Boundary conditions for the local model are driven by global displacements. Maximum and minimum J-integrals are calculated at two extreme configurations for a single belt running cycle. The range of the J-integral is input into the curve fitted power law to derive the fatigue crack growth rate and hence the fatigue life for the belt.

A known factor which limits the life cycle performance of automotive front-end accessory serpentine belt drive is cracking of the elastomer located in the rib tip. In this paper, fracture mechanics was used to study crack growth in belt rib. Tearing energy and J-integral were employed to characterize the fracture behavior of rubber compound. A global-local strategy was adopted to predict the crack initiation in V-ribbed belt rib. The global finite element model of the belt was created with relatively coarse mesh. The local model with fine mesh around the crack tip region was used to evaluate the J-integral. The J-integral computed using finite element analysis was compared with the threshold value found by experiments to predict the onset of crack initiation in belt rib.

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.

A three-dimensional dynamic finite element model was built to study the stress distribution in V-ribbed belts. Commercial finite element code ABAQUS was used for the simulation. The model consists of a pulley and a segment of V-ribbed belt in contact with the pulley. Different belt pulley tracking configurations can be obtained by varying the pulley diameter and the belt wrap angle. Belt tension and pulley rotating speed can be controlled by the load and boundary conditions. Both driving and driven pulley can be modeled by applying different sets of load and boundary conditions. Rubber is modeled as hyperelastic material. Reinforcing cord and fabric are modeled as rebar defined in ABAQUS. Emphasis was put on the belt rib tip stress because it causes belt wear and belt rib fatigue cracking. The stress at the belt rib tips depends on tension in the belt, pulley contact friction coefficients, rib rubber properties, pulley diameter and belt wrap angle.

A general three-dimensional finite element model was built to simulate the tracking conditions inherent in automotive front-end accessory drives, specifically, serpentine V-ribbed belt drives. Commercial finite element code ABAQUS was used for the simulation. The analysis is based on a hyper-elastic material model for the belt, and includes the effect of the reinforced cords and fibers in the rubber compound. The model can be used to study different parameters of the belt drive system such as rib number, pulley misalignment, drive wrap angle and drive speed. Experiments were used to validate the finite element model. Belt misalignment force of two, four and six ribbed belts under different misalignment conditions was obtained from experiment and compared with the results from the finite element model. Good correlation between these results brings confidence to the finite element model. Finally, typical FEA simulation results for a six-ribbed belt are presented.

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.