A two-fixed-end beam piezoelectric inertial actuator using electromagnet controlled magnetorheological fluid (MRF) for friction regulation

2020 ◽  
Vol 29 (6) ◽  
pp. 065011 ◽  
Author(s):  
Jianming Wen ◽  
Dezhu Shen ◽  
Renming Wang ◽  
Jianping Li ◽  
Jijie Ma
PCI Journal ◽  
1966 ◽  
Vol 11 (1) ◽  
pp. 75-94
Author(s):  
Duryl M. Bailey ◽  
Phil M. Ferguson

2020 ◽  
Vol 65 (1) ◽  
pp. 137-144
Author(s):  
Marius-Vasile Pop

This paper presents a method to find the severity of a crack for cantilever beams that can be used to estimate the frequency drop due to the crack. The severity is found for the crack located at the location where the biggest curvature (or bending moment) is achieved. Because the fixing condition does not permit a symmetrical deformation around the crack, the apparent severity is smaller as the real one. The latter is found by the estimated value of the trend-line at the fixed end, it being constructed on points that consider the crack position (equidistant points in the proximity of the fixed end) and the resulted deflections.


1999 ◽  
Author(s):  
Julien Bernard ◽  
George Lesieutre ◽  
Gary Koopmann
Keyword(s):  

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 410
Author(s):  
Dan Liu ◽  
Xiaoming Liu ◽  
Pengyun Li ◽  
Xiaoqing Tang ◽  
Masaru Kojima ◽  
...  

In recent years, micromanipulators have provided the ability to interact with micro-objects in industrial and biomedical fields. However, traditional manipulators still encounter challenges in gaining the force feedback at the micro-scale. In this paper, we present a micronewton force-controlled two-finger microhand with a soft magnetic end-effector for stable grasping. In this system, a homemade electromagnet was used as the driving device to execute micro-objects manipulation. There were two soft end-effectors with diameters of 300 μm. One was a fixed end-effector that was only made of hydrogel, and the other one was a magnetic end-effector that contained a uniform mixture of polydimethylsiloxane (PDMS) and paramagnetic particles. The magnetic force on the soft magnetic end-effector was calibrated using an atomic force microscopy (AFM) probe. The performance tests demonstrated that the magnetically driven soft microhand had a grasping range of 0–260 μm, which allowed a clamping force with a resolution of 0.48 μN. The stable grasping capability of the magnetically driven soft microhand was validated by grasping different sized microbeads, transport under different velocities, and assembly of microbeads. The proposed system enables force-controlled manipulation, and we believe it has great potential in biological and industrial micromanipulation.


Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 132
Author(s):  
Jon Gutiérrez ◽  
Virginia Vadillo ◽  
Ainara Gómez ◽  
Joanes Berasategi ◽  
Maite Insausti ◽  
...  

Recently, our collaborative work in the fabrication of a magnetorheological fluid (MRF) containing high magnetization FeCo nanoparticles (NPs, fabricated in our laboratories using the chemical reduction technique; MS = 212 Am2/kg) as magnetic fillers have resulted in a new MRF with superior performance up to 616.7 kA/m. The MRF had a yield stress value of 2729 Pa and good reversibility after a demagnetization process. This value competes with the best ones reported in the most recent literature. Nevertheless, the fabrication process of this type of fluid is not an easy task since there is a strong trend to the aggregation of the FeCo NPs due to the strong magnetic dipolar interaction among them. Thus, now we present the analysis of some aspects concerning the fabrication process of our FeCo NPs containing MRF, mainly the type of surfactant used to cover those NPs (oleic acid or aluminium stearate) and its concentration, and the procedure followed (mechanical and/or ultrasound stirring) to achieve a good dispersion of those magnetic fillers within the fluid.


1985 ◽  
Vol 52 (2) ◽  
pp. 439-445 ◽  
Author(s):  
T. J. Ross

The problem of a viscoelastic Timoshenko beam subjected to a transversely applied step-loading is solved using the Laplace transform method. It is established that the support shear force is amplified more than the support bending moment for a fixed-end beam when strain rate influences are accounted for implicitly in the viscoelastic constitutive formulation.


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