INFLATION OF HYPERELASTIC CYLINDRICAL MEMBRANES AS APPLIED TO BLOW MOLDING .2. NON-AXISYMMETRICAL CASE

The non-axisymmetric confined inflation of an isotropic homogeneous cy lindrical membrane is considered in this study. The material is assume d to obey the Mooney-Rivlin constitutive model. The continuum-based fo rmulation is adopted, with the resulting equilibrium partial different ial equations, governing the deformation field, solved using a Galerki n based finite element procedure. Upon contact, the inflating material is assumed to stick to the solid boundary. The, dependent variables c orresponding to nodes which have contacted are then fixed for subseque nt deformation. In an attempt to simulate the inflation stage of the b low-moulding process, the method is illustrated through some examples of moulded tapered rectangular bottles with centered and off-centred n eck. Examples of initial membranes of uniform and non-uniform thicknes s distribution are examined. Experiments are carried out in an attempt to validate the theory, in particular, to compare the predicted and m easured final thickness distributions of blow-moulded containers.