• Andres, M. T.
• Greve, Lars
• Ramaker, Kenny
• Eller, Tom
• Hazrati, Javad
• Van Den Boogaard, Ton

Abstract

A constitutive model is presented for the three-layer steel composite Tribond® 1200. Tribond® is a hot forming steel which consists of three layers: a high strength steel core between two outer layers of ductile low strength steel. The model is designed to provide an accurate prediction of the deformation behavior of the material up to the point of fracture. Moreover, it includes a fracture prediction criterion that accounts for the complex loading paths experienced by the material in the event of a crash. For calibration of the material model, experiments are performed both with core layer only and with full Tribond® specimens. Separate plasticity and fracture models are calibrated based on these experiments. The transition zone between the layers is modeled by interpolating between the calibrated models. The strain hardening models are calibrated using an inverse FEM optimization routine, that takes into account measured force–displacement curves and strain fields. The fracture behavior is represented by a stress triaxiality and Lode angle dependent, strain-based fracture criterion. Five different fracture tests are used to obtain data at different stress states: notched and central-hole tensile tests, a shear test, a bulge test and a bending test. The model is validated with a bending-dominated L-section compression test.

Topics

• impedance spectroscopy
• experiment
• simulation
• strength
• steel
• shear test
• composite
• bending flexural test
• compression test
• forming
• plasticity
• fracture behavior