Modeling of Seed Cotton Viscoelastic Properties

Abstract

Seed cotton is commonly compressed into modules following harvest for storage and transport, yet mathematical models for the prediction of compressed density are unavailable. The ability to predict final seed cotton density based on the applied compressive force, deformation, and time is needed to provide a basis for engineering systems that can maintain seed cotton quality during extended storage. The impact of factors such as loading density, harvest method, hold time, and loading method was evaluated, and predictive models were developed. A Burgers model with an inelastic strain element originally used with forages was used to model the compression and creep relationships of seed cotton. Compressed density was adequately described (R2 ~0.98), but residual errors indicated that some aspect of the compression behavior remained unexplained. The creep (time-dependent strain) was also accurately modeled (R2 ~0.99). The pattern of the residual errors indicated that additional terms may improve the model. Improved distribution of seed cotton within the module builder is necessary to produce a desirably shaped module. The improved understanding of seed cotton compressive properties will aid in the development of systems to improve the module builder and maintain seed cotton quality during storage.