Plasticity and failure behavior modeling of high-strength steels under various strain rates and temperatures: microstructure to components

Abstract

The aim of this study is to establish an integrated material modelling approach, micro, macro and component scales, for investigating the plasticity, damage and fracture behaviour of modern high-strength steels under various strain rates and temperatures. With the established relations between different scales, the approach ultimately provides a knowledge-based and efficient alternative for the damage-tolerant microstructure design to the conventional empirical rules. In this study, we will present the models working at different scales and the scaling strategy between them. For a more general application than quasistatic and room temperature, the models are formulated with strain rate and temperature dependency. All models are calibrated by experiments on the corresponding scale and also validated by experiments not involved in the calibration procedure or tests from a higher length scale. As the ultimate goal of the approach is to guide the microstructure design, a fine-resolution digital representation of the microstructure is targeted in the study. In addition to the standard phase fraction, grain size and shape features, fine-tuning of the microstructural features, such as texture and misorientation distribution is also implemented into the synthetic microstructure model. The impact of these individual microstructure features and their combination on the macroscopic and component level performance is studied and the optimized microstructure for the desired improvement of the mechanical property can be identified by the proposed approach.