Forming limit diagram prediction of AA5052/polyethylene/AA5052 sandwich sheets: Fid-Bau Portal

Forming limit diagram prediction of AA5052/polyethylene/AA5052 sandwich sheets

Liu, Jianguang / Liu, Wei / Xue, Wei

Highlights ► An AA5052/polyethylene/AA5052 sandwich sheet is developed. ► A numerical simulation method is proposed to predict the forming limit diagram of sandwich sheet. ► The formabilities of sandwich sheet are better than those of monolithic sheet. ► The forming limit diagram of sandwich sheet shifts to higher value with increasing the thickness of polyethylene.

Abstract Metal–plastic sandwich sheet has received increasing attention in aeronautical, automotive, marine and civil engineering industries due to its lower density, higher specific flexural stiffness, better dent resistance, better sound and vibration damping characteristics. In the present study, an AA5052/polyethylene/AA5052 sandwich sheet is developed and its formabilities are investigated. A numerical simulation method based on the Gurson–Tvergaard–Needleman (GTN) damage model is used for simulating the forming process of sandwich sheet, in which the interface conditions between skin sheet and core materials are considered by using the cohesive zone model (CZM). The rigid punch dome tests and the Nakazima forming tests are carried out to build the forming limit diagrams (FLDs) of sandwich sheet. A strain history method is applied to determine the limited strain. Comparisons between predictions and experimental results validate the used numerical simulation method. Finally, the influences of polyethylene’s thickness on the formabilities of sandwich sheet are analyzed. Research results show that: AA5052/polyethylene/AA5052 sandwich sheet has a better formability than monolithic AA5052 sheet and the formability of AA5052/polyethylene/AA5052 sandwich sheet increases with increasing the thickness of polyethylene core layer.