Hysteresis Behavior of Magnetorheological Elastomer: A Study of Linear and Nonlinear Viscoelastic Regions

Understanding the viscoelastic properties of magnetorheological elastomer (MRE) is essential for their effective implementation in controllable devices. In practical applications, MRE is frequently subjected to cyclic loading and unloading conditions, which are commonly represented by stress–strain hysteresis loops. This study aims to characterize the stress–strain hysteresis behavior of MRE within the linear viscoelastic (LVE) and nonlinear viscoelastic (non-LVE) regions. Silicone rubber-based MRE were fabricated using 70 wt% of irregularly shaped carbonyl iron particles (CIP). A strain sweep test was conducted to identify the boundaries of the LVE and non-LVE regions. Subsequently, cyclic steady-state shear tests were performed to analyze the hysteresis behavior in both regions. In the LVE region, the MRE exhibited a nearly elliptical hysteresis loop with a small area, indicating predominantly elastic behavior and minimal energy dissipation. In contrast, the non-LVE region exhibited pronounced nonlinear behavior and significantly larger hysteresis areas, reflecting increased energy dissipation. As a result, the hysteresis behavior in the non-LVE region presents greater challenges for modeling and prediction due to its inherent complexity and nonlinear characteristics.