Steel reinforcements are commonly used to strengthen rubber hoses which are used in high pressure applications in field of engineering. It has been found through experiments that reinforced hoses becomes very stiff when subjected to pressure. Thus, there is a requirement to model reinforcements which would predict the effect of stiffening. Modelling helically wounded reinforcements are the main focus of the work.
Deformation of helically reinforced rubber hoses under pressure depend on the helix angle at which the reinforcement is laid around the hose.
The current study is carried out at Fraunhofer Chalmers Centre and uses its in-house solver to perform numerical calculations and additional functionalities have been added to the solver to model reinforcements.
The reinforcements are generally modeled using one dimensional elements which are incorporated inside a volume model of rubber. In this work, truss elements are formulated to model reinforcements. Primarily, two models have been implemented namely the coupled model which models rubber and reinforcements separately with a spring constraint on the their displacements to couple them together and an embedded model which involves adding the stiffness contribution of the 1D model to the 3D model. Other simplified models have also been considered.
The effect of the neutral angle at which the reinforced hose does not deform has been captured by all the models with the coupled and embedded models having a good agreement with the theoretical value. Further, bending and torsion experiments are simulated using the coupled model.
The results of these simulations shows that the model is able to demonstrate the stiffening effect of reinforced hoses and that there is a dependency between pressure and the stiffness of the hose.