Springback Behavior of Aluminum/Polypropylene/Aluminum Sandwich Laminates

Abstract

The springback of sheet metals after forming has been widely studied for decades using numerical and experimental methods. Many of these springback studies involve aluminum alloys. This study aims to understand the springback behavior of aluminum-polypropylene-aluminum laminates as they are being used increasingly in automotive and other applications because of their weight saving potential. A finite element model of the draw bending of a U-channel based on Numisheet’93 benchmark study is built using LS-DYNA. First, the model is validated and studied for springback prediction of single AA5182-O aluminum alloy sheets, and then it is extended to the study of the springback behaviors of AA5182-O/polypropylene/AA5182-O laminates with various combinations of core and skin thicknesses. The numerical model is also validated by experiment. Effects of various tool design and process parameters, such die radius, punch radius and blank holder force, on the springback of the sandwich laminates are studied. The effect of numerical modeling parameters is also considered.