scholarly journals Investigation of the well-dispersed magnetorheological oil-based suspension with superparamagnetic nanoparticles using modified split Hopkinson pressure bar

2021 ◽  
Author(s):  
Magdalena Osial ◽  
Michał Nowicki ◽  
Ewa Klejman ◽  
Leszek Frąś

AbstractMagnetorheological (MR) fluids are classified as smart materials whose viscoplastic characteristics change under the magnetic field. They are widely applied for dynamic energy dissipation due to their rapid thickening under the external magnetic field. In this work, the core–shell suspension of superparamagnetic iron oxide-based nanoparticles was synthesized and dispersed in silicone oil. Much effort has been made to prepare suspension meeting requirements of MR fluid. The experimental squeezing flow response was studied using a modified split Hopkinson pressure bar (SHPB) with various shear rates. Tests with modified SHPB show that MR fluid rapidly responds to the compression thickening and forming chain-like structures. MR fluid dissipates the energy generated during compression stress tests. This study presents a simple and cost-effective synthesis way suitable for MR fluid formation for its dynamic energy dissipation application.

2013 ◽  
Vol 20 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Wojciech Moćko

Abstract The paper presents the results of the analysis of the striker shape impact on the shape of the mechanical elastic wave generated in the Hopkinson bar. The influence of the tensometer amplifier bandwidth on the stress-strain characteristics obtained in this method was analyzed too. For the purposes of analyzing under the computing environment ABAQUS / Explicit the test bench model was created, and then the analysis of the process of dynamic deformation of the specimen with specific mechanical parameters was carried out. Based on those tests, it was found that the geometry of the end of the striker has an effect on the form of the loading wave and the spectral width of the signal of that wave. Reduction of the striker end diameter reduces unwanted oscillations, however, adversely affects the time of strain rate stabilization. It was determined for the assumed test bench configuration that a tensometric measurement system with a bandwidth equal to 50 kHz is sufficient


2015 ◽  
Vol 816 ◽  
pp. 795-803
Author(s):  
Yan Ling Wang ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Rui Liu

The mechanical properties and fracture failure behavior of the near β-type Ti-5Al-5Mo-5V-3Cr-X (X = 1Fe or 1Zr) titanium alloys were studied by Split Hopkinson Pressure Bar (SHPB) experiment under the dynamic loading conditions at a strain rate of 1.5 × 103 s-1–5.0 × 103 s-1. Results showed that the SHPB specimen fractured in the direction of maximum shearing stress at an angle of 45° with the compression axis. The fracture surface revealed the shear and tension zones with cleavage steps and parabolic dimples. Severe early unloading was observed on the Ti-5553 alloy under a strain rate of 4,900 s-1 loading condition, and the dynamic property of the Ti-55531Zr alloy was proved to be the optimal.


Sign in / Sign up

Export Citation Format

Share Document