Analytical and experimental study on bonding behavior at the roll gap during complex rolling of sandwich sheets

An extended analytical model for complex rolling of sandwich sheets is prop osed. Effects of various rolling conditions such as the flow stress ratio a nd initial thickness ratio of the raw sheets, total thickness reduction, et c., upon the bonding factors such as the bonding length, mean contact press ure, and the relative sliding distance at the interface as well as the newl y generated surface ratio are analyzed. Furthermore, experiments on complex rolling of sandwich sheets are also conducted. The measured rolling force, thickness ratio of the rolled product, bonding length, and the mean contac t pressure are close to the theoretical values. Through the comparisons, th e validity of this proposed mathematical model is verified and the characte ristics of the bonding behavior at the roll gap during complex rolling of s andwich sheets are manifested. (C) 2000 Elsevier Science Ltd. All rights re served.