Colloquia

Summary

This master’s assignment is carried out at Pronexos; the commercial brand of the Enrichment Technology Company in Almelo. Pronexos’ core business is the production of carbon fibre reinforced plastic (CFRP) rollers. These are used in the paper- and foil industry to guide paper or foil through various machines. A key design aspect of these rollers is the bending deflection caused either by the foil being tensioned around the roller, or by contact from another roller. The bending deflection is calculated via analytical tools based on the Timoshenko-Ehrenfest beam theory and on the Classical Lamination Theory. The objective of this research is to validate the methodology currently used to calculate the bending deflection of a roller.

The first step in achieving this goal is obtaining the material properties of the used materials. Filament wound products contain two characteristics which makes them unsuitable for traditional measurement techniques used to determine the material properties. These are the round or curved shapes making specimen extraction challenging, and the impossibility to create unidirectional laminates. This work therefore uses an optimization algorithm to minimize the differences between experimental data, measured on curved specimens with various lay-ups, and finite element models, by altering the material properties until convergence is reached. The obtained material properties are validated using a three point bending experiment on three separate rollers, demonstrating excellent agreement between model and experiment.

Lastly, the new material properties are used in two finite element models which calculate the displacement of a roller under two different loads, these are compared with the numerical calculations. Seven variables are varied in fraction factorial experimental design, the influence of each parameter on the accuracy of the calculation method is determined. Lastly, an improvement to the calculation method is proposed in the form of a correction factor.