Finding engineering applications for a new class of smart material, magnetorheological elastomer (MRE), has been a major task for researchers in this field. Novel MRE devices, such as vibration absorbers and vibration isolators, have been proposed and fabricated to pioneer its engineering applications. In civil engineering, the author has proposed a novel MRE based isolator to be used in the base isolation system for mitigating the devastating effects of earthquakes on civil structures. For any MRE-based device, electromagnetic coil is evitable involved to provide magnetic field for the MRE materials. Comparing with magnetic circuit design in magnetorheological fluid (MRF) device, i.e. MR damper, MRE devices normally need a larger coil to energize the MRE materials, particularly for a large-scale MRE device. Therefore, investigation of the solenoid on the magnetic field distribution is of great importance for the design and development of MRE based device. In particular, provision of sufficient and uniform magnetic field is essential towards the success in designing MRF/MRE devices. To understand the mechanism of magnetic field generation in a solenoid is the key for device design and optimization. The main objective of this paper is to analytically investigate and experimentally validate the magnetic field distribution in a solenoid. The theoretical investigation starts from the analysis on an ideally thin cylindrical solenoid in order to obtain analytical results. To stimulate the coil which can be used in the design of MRE device, theoretical investigation is to conduct on a thick-wall cylindrical solenoid. Finite element analysis is also used to examine the magnetic field distribution in the solenoid. In order to verify the theoretical findings, experimental testing is conducted to acquire the magnetic field distribution in a sample solenoid. Results from analytical solution, finite element analysis and experimental testing agree very well. The findings provide valuable information for the design and optimization of the MRE device in which a solenoid is inevitably involved.
