Dynamics Modeling to Inform Design Optimization

This paper presents the methods employed in modeling a vibratory conveyor for use in model-based design optimization. The conveyor, essentially a large table whose top oscillates at an angle off of horizontal, uses springs between the drive mechanism and the tabletop to directly apply a sinusoidal excitation. These springs prevent the system from losing response amplitude as load is increased. The manufacturer is having difficulty optimizing performance and reliability in newer designs, and has requested a model-based approach to the design optimization. This study discusses the initial steps taken in modeling the original mechanism design, specifically the dynamic model and experimental determination of the necessary spring constants. The first full iteration of the model starts with low detail and simplified geometry, with a plan to add complexity as needed to improve accuracy. In the initial model, the parallel springs in the tabletop suspension are combined, bypassing the spring mounting geometry, and tested as one large spring. The drive mechanism springs, bars of fiber reinforced plastic (FRP), are more meticulously tested in a tensile testing machine. The resulting spring constants are used in the initial model to calculate the sinusoidal response of the tabletop at any given input frequency. The deflection response per time of the tabletop is then measured and compared to the model. Conclusions detail the initial model’s accuracy and Future Work examines how to bring it in closer agreement with the real machine’s sinusoidal response.