Review of the troughability test ISO 703 for quantifying a uniform transverse bending stiffness for conveyor belts

This paper presents a review of the troughability test specified in standard ISO 703 and associated models for quantifying the effective modulus of elasticity for uniform belt bending stiffness. For the interpretation of the test results, four analytical methods are employed: two theoretical ones that assume inextensible nonlinear bending of the belt's structure using the Euler-Bernoulli beam theory, and a Finite Element Method (FEM). The latter includes not only bending, but also stretching and shear effects, accommodating the Timoshenko theory for model with beam elements and the Mindlin-Reissner theory for model with shell elements. The present study compares the models, gives recommendations regarding their application and usage limitations. The impact of the varying effective modulus of elasticity, line mass and geometry on the belt's troughability is investigated within established parameters and limitations inherent to conveyor belts. The results indicate that the troughability test (ISO 703) in combination with an appropriate choice of the model for data extraction can be used for quantifying the effective modulus of elasticity. This conclusion is limited to small strain conditions (up till 5%). Analyses reveal that thick and narrow belts with a small belt width-to-thickness ratio reach this strain limitation at smaller troughability values.