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.

This paper presents a new approach to determine the bending stiffness of a pipe conveyor belt that is sufficient to form a stable pipe shape based on its throughability performance. The paper describes the mathematical model that determines pipe conveyor contact forces and introduces two numerical models solved using FEM in ANSYS. Results agree with the experimental data obtained using a six-point stiffness device. The mathematical model proposed can be used as a uniform validation technique for any numerical model. Appearance of one of the contact forces that equals zero is considered as a criterion for insufficient bending stiffness of belt to form a stable pipe shape. Effective modulus of elasticity quantified from the throughability parameter becomes a link to express belt pipe-ability. Impact of belt line mass and bending stiffness is investigated: for the same belt geometry, heavier belts require higher bending stiffness for the correct pipe shape formation.