Abstract: The analytical springback prediction model of tailor welded blanks(TWBs) for air bending process is put forward for small curvature bending, the forming process is divided into no warp-around condition and warp-around condition respectively. At the air bending unloading phase, the interaction moment of the two parent blanks is introduced to the model in which the variable modulus is included with plastic deformation proceeding, the unloaded angle is obtained based on a single parent plate in the analytical model. An online method for measuring unloaded angle is used based on two dimension homography matrix transformation method. In the springback control system, the training set is constructed using orthogonal table to include the material parameter fluctuation. The TWBs springback control system is developed using LabVIEW software platform. In the springback control system, the target unloaded angles 140° and 100° are set, the maximum manufacturing errors are decreased to 1.42% and 2.01% respectively by tracing the online results after 5 cycles.

Key words: tailor welded blanks;air bending;springback control