The structural behaviors and strength of actual pressure PET bottle have been investigated, mainly by experimental measurements under internal pressure. First, tensile tests of PET resin material for PET bottle were carried out in order to obtain the fundamental tensile properties and the stress-strain diagram. Then, the mechanical behaviors of PET bottle were found by strain measurements under internal pressures. Finally, burst tests were conducted for 21 PET bottles. In the present burst tests, resulted magnitudes of burst pressures were not so much scattered, within the range of 1. 9∼2. 3 MPa. Fractured shapes of bottles by bursting would be categorized in three kinds of I, L, X types.
For trial, burst pressure evaluation for the bottle were made by applying the theoretical analysis of N. L. Svensson. The calculated bursting pressure and radial deflection were numerically near the experimental values. However, in further investigation for more rigorous solutions, the following items are to be studied: (1)The material properties including stress-strain diagram for the actual bi-axially oriented PET bottle itself formed by blow molding, not only PET resin material. (2)The development of analytical approach for large deformation to the range of bursting.
