Numerical Simulation for Microstructure Evolution and Shear Properties of Magnetorheological Gels

Abstract

The rheological properties and shear performance of magnetorheological (MR) gels have been extensively studied based on experimental methods. However, viscoelastic theoretical models that can quantify the interaction between the matrix and particles, as well as numerical simulations on the mechanical properties and the microstructure evolution of MR gels, are still relatively few and need to be further investigated. In this paper, based on the non-Newtonian fluid equation and Kelvin viscoelastic model, a modified viscoelastic resistance model is proposed, which can describe the interaction between the matrix and particles. The consistency coefficient, flow behavior index, particle size, and motion velocity are considered comprehensively in the viscoelastic resistance equation. Based on the established theoretical model, the numerical simulation approach is developed to study the evolution of chain-like microstructures and the shear properties of MR gels. The response time of MR gels under different magnetic fields and matrixes is analyzed from the perspective of energy. It shows that the effect of magnetic field intensity on the shear strength of MR gels is consistent with the magnetization characteristics of particles. The maximum shear stress and flow stress are significantly affected by viscosity parameters of the matrix and shear rate, which are related to the strength of shear-bearing chains and recombination rate of dissociative chains. The relevant influence mechanism of the microstructures on the macroshear properties is explored.

Effect of Bi content and temperature on the shear mechanical properties of Fe-Bi nanocomposites: a molecular dynamics study

“…Enhancing the shear mechanical properties of free-cutting steels ensures the dimensional and shape accuracy of machined parts, while also improving the lifespan and stability of components made from these steels. With the continuous development of materials science, researchers are increasingly focusing on the correlation between the microstructure of materials and their shear behavior [24][25][26]. Molecular dynamics (MD) simulations can model the motions and interactions of atoms and molecules under given conditions to reveal the microstructure, dynamical behavior and properties of materials [27].…”

Effect of microstructure evolution on the mechanical behavior of magneto-active elastomers with different matrix stiffness

“…17,54 In terms of modeling, several papers have studied particle rearrangement at the micro-scale. [55][56][57][58][59][60] However, particle rearrangement induces high deformations in the matrix and particles can come very close to each other, which poses challenges for direct solutions to fully coupled finite element problems. 61 This paper proposes an effective model that accounts for microstructural evolution and the initial sample shape of MAEs.…”