A rate-dependent damage mechanics model for predicting plasticity and ductile fracture behavior of sheet metals at high strain rates

Engineering Fracture Mechanics, vol. 306, pp. 110217

Abstract

Uniaxial tensile tests were performed on H340 steel sheets at different strain rates (10-4 to 103 s-1) and temperatures (–30 °C and 280 °C). Oscillation-free forces were measured during high-speed tests at strain rates of up to 1000 s-1 using specimens with different stress states. Material hardening curve, strain rate sensitivity, temperature effects, and Taylor-Quinney coefficient for adiabatic temperature calculations were determined in experiments. Digital image correlation (DIC) technique was employed to measure displacement, deformation, and local strain fields. Meanwhile, the temperature fields of specimen gauge section were measured with a high–speed thermal camera in the uniaxial tensile tests at various strain rates. Damage and fracture-related parameters were calibrated and validated using porosity measurements on SEM micrographs and in combination with finite element (FE) simulations. A rate– and temperature–dependent plasticity and damage mechanics model (e2MBW) was proposed and calibrated to predict the plasticity and fracture behavior of H340 under different loading speeds. The study demonstrated good agreement in the overall experimental and simulated force–displacement responses and local strain evolution across all fracture specimens at loading speeds from 0.005 mm/s to 10000 mm/s.

Authors 5

1. Chongyang Zeng

   University of Siegen

   Affiliation as printed

   Institute of Automotive Lightweight Design, University of Siegen, Siegen, Germany

2. Xiangfan Fang corresponding

   University of Siegen

   Affiliation as printed

   Institute of Automotive Lightweight Design, University of Siegen, Siegen, Germany

3. Niloufar Habibi Aachen Institute of Metal Forming

   RWTH Aachen University

   Affiliation as printed

   Institute of Metal Forming, RWTH Aachen University, Aachen, Germany

4. Sebastian Münstermann Aachen Institute of Metal Forming

   RWTH Aachen University

   Affiliation as printed

   Institute of Metal Forming, RWTH Aachen University, Aachen, Germany

5. Junhe Lian

   Aalto University

   Affiliation as printed

   Department of Mechanical Engineering, Aalto University, Espoo, Finland