Multiscale Modeling of the Mechanical Behaviour of Pearlitic Steel

Pearlitic steel is a two-phase material with cementite lamellae embedded in a ferrite matrix. In this contribution a representative microscale model, capturing the behavior of the cementite and the ferrite and also the interaction between these phases, is proposed. The response from the micromodel is coupled by means of computational homogenization to a representative mesomodel containing grains, or colonies, of pearlite. The material parameters of the ferrite and the cementite are identified by calibrating the model to experimental data for the pearlitic steel R260. Different types of prolongation conditions, i.e. how to couple the mesoscale kinematics to the microscale kinematics, are investigated and their results are compared. Finally, the influence of the number of cementite directions and the number of crystallographic orientations on the macroscopic stress response is studied. Thereby, a sufficient mesomodel size is estimated

On the Prediction of Macroscopic Yield Surfaces of a Pearlitic Steel using Multiscale Modeling

On the microscale, pearlite consists of hard and brittle cementite lamellae embedded in a ductile ferrite matrix. The cementite lamellae are arranged in colonies within which the lamella orientation is ideally constant. This composite-like constitution, on the microscale, makes pearlitic steels ideally suited for multiscale modeling. In this contribution a three-scale multiscale modeling setup is used to describe the mechanical behav- ior of a pearlitic steel. The macroscale represents the engineering scale on which a typical structural component would be analyzed. The mesoscale comprises colonies, with varying orientations (both mor- phological and crystallographic), thereby enabling the interactions between colonies to be taken into account. On the microscale a model representing the lamellar structure of pearlite is used. This model accounts for the behavior of the constituents but also the interactions between them. A cornerstone in this contribution is the formulation of a macroscopic, energy based, yield criterion based on homogenized quantities (cf. e.g. [1, 2, 3]). With such a criterion macroscopic yield surfaces can be predicted. The impact of altering the prolongation condition on the resulting yield surface is studied. Furthermore, the effect of adding a pre-loading before carrying out the yield surface prediction is investigated. Regarding the topic of how to identify the correct values of the parameters in a multiscale model several possibilities exists. This topic will be discussed briefly

On the Prediction of Anisotropy Evolution in Polycrystalline Multiphase Materials

In this contribution a multiscale modeling (MSM) framework is used to model the behavior of a multi-phase polycrystalline material. The use of MSM is motivated by the interest in how mechanisms occuring at different length scales contribute to the macroscopic behavior

Преимущества модели Quadruple helix для высших учебных заведений

Материалы XI Междунар. науч. конф. студентов, аспирантов и молодых ученых, Гомель, 17-18 мая 2018 г