Superplastic Rectangular Bulging of AA8090 Numerical Modeling: Validation and Development

Superplastic bulging forming is a hot manufacturing process widely used in the aerospace industry for its capability to produce complex shapes and decrease the joining operations but it has some drawbacks that make its monitoring quite difficult in terms of pressure regulation and strain rate control. A finite elements model of superplastic rectangular bulging of Al-Li alloy AA8090 was built and developed using Abaqus commercial code. The FE model was validated based on the thickness ratio distribution along the length and the width of the rectangular cavity of the die, besides the ratio of max creep strain rate over the target creep strain rate profile. The development of the model was proposed to enhance the accuracy of thickness distribution results by changing the friction coefficient of the contact between the die and the sheet. The obtained results were analyzed and explained and the new model gave promising results with good accuracy with respect to the experimental findings.