On a Simplified Method for Solving Impulsively Loaded Structures of Rate-Sensitive Materials

1965 ◽  
Vol 32 (3) ◽  
pp. 489-492 ◽  
Author(s):  
Nicholas Perrone
Keyword(s):  
Yield Stress ◽  
Rate Sensitivity ◽  
Approximate Solutions ◽  
Exponential Rate ◽  
Structural Elements ◽  
Sensitive Material ◽  
Perfectly Plastic ◽  
Simplified Method ◽  
Dynamic Yield ◽  
Constant Yield

In an attempt to assess more completely rate-sensitive material effects, two fundamental structural elements are analyzed: A wire with an impulsively loaded end mass, and an impulsively loaded ring. The ring and wire are made of perfectly plastic, rate-sensitive materials. In each case, exact and approximate solutions are obtained for an exponential rate-sensitivity law. The results suggest that very good approximations to the exact solutions may be found by utilizing a rate-insensitive material with constant yield stress equal to the initial dynamic yield stress.

Magnetic field dependent steady-state shear response of Fe3O4 micro-octahedron based magnetorheological fluids

2018 ◽  
Vol 20 (30) ◽  
pp. 20247-20256 ◽  
Author(s):  
A. V. Anupama ◽  
V. B. Khopkar ◽  
V. Kumaran ◽  
B. Sahoo
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Rheological Behaviour ◽  
Magnetorheological Fluids ◽  
Shear Response ◽  
Field Dependent ◽  
Dynamic Yield ◽  
Magneto Rheological

The magneto-rheological behaviour of fluids containing soft-ferrimagnetic Fe3O4 micro-octahedrons (M = magnetization, τY = dynamic yield-stress and H = applied-magnetic-field).

scholarly journals Влияние гигантской магнитострикции на динамический предел текучести в условиях высокоскоростной деформации

2021 ◽  
Vol 63 (12) ◽  
pp. 2070
Author(s):  
В.В. Малашенко
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Yield Stress ◽  
High Strain ◽  
Dynamic Yield Stress ◽  
High Strain Rate Deformation ◽  
Dynamic Yield ◽  
Giant Magnetostriction

The high-strain rate deformation of crystals with giant magnetostriction is theoretically analyzed. It is shown that giant magnetostriction has a significant effect on the dynamic yield stress of crystals.

scholarly journals Effects of Silicone Oil Viscosity and Carbonyl Iron Particle Weight Fraction and Size on Yield Stress for Magnetorheological Grease Based on a New Preparation Technique

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1778 ◽  
Author(s):  
Kejie Wang ◽  
Xiaomin Dong ◽  
Junli Li ◽  
Kaiyuan Shi ◽  
Keju Li
Keyword(s):  
Yield Stress ◽  
Carbonyl Iron ◽  
Silicone Oil ◽  
Weight Fraction ◽  
Iron Particle ◽  
Preparation Technique ◽  
Oil Viscosity ◽  
Dynamic Yield Stress ◽  
Carbonyl Iron Particle ◽  
Dynamic Yield

This paper investigated the effects of silicone oil viscosity (SOV) and carbonyl iron particle (CIP) weight fraction and size on dynamic yield stress for magnetorheological (MR) grease. The MR grease samples were prepared using orthogonal array L9 on the basis of a new preparation technology. The shear rheological tests were undertaken using a rotational shear rheometer and yield stress was obtained based on the Bingham fluid model. It was found that CIP fractions ranging from 65 wt% to 75 wt% and SOV varying from 50 m2·s−1 to 1000 m2·s−1 significantly affect the magnetic field-dependent yield stress of MR grease, but the CIPs with sizes of 3.2–3.9 μm hardly had any influence based on the analysis of variance (ANOVA). In addition, the yield stress of MR grease mainly depended on the CIP fraction and SOV by comparing their percent contribution (PC). It was further confirmed that there were positive effects of CIP fraction and SOV on yield stress through response surface analysis (RSA). The results showed a high dynamic yield stress. It indicated that MR grease is an intelligent material candidate which can be applied to many different areas requiring high field-induced rheological capabilities without flow for suspension. Moreover, based upon the multivariate regression equation, a constitutive model was developed to express the function of the yield stress as the SOV and fraction of CIPs under the application of magnetic fields.

INFLUENCE OF SURFACTANTS ON PROPERTIES OF ELECTRORHEOLOGICAL FLUIDS CONTAINING POLYANILINE

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2461-2467 ◽  
Author(s):  
MAŁGORZATA BOCIŃSKA ◽  
HENRYK WYCIŚLIK ◽  
MARCIN OSUCHOWSKI ◽  
JANUSZ PŁOCHARSKI
Keyword(s):  
Yield Stress ◽  
Current Density ◽  
Silicone Oil ◽  
Flow Curves ◽  
Different Types ◽  
Order Of Magnitude ◽  
Dynamic Yield ◽  
Rate Of Sedimentation ◽  
Er Fluids

Sedimentation which is a natural process in most of ER fluids can be reduced by addition of surfactants that influence also other properties of the fluids. To study both the ER effect and the rate of sedimentation was the aim of the investigations. The ER fluids comprised powdered polyaniline and silicone oil to which surfactants of different polarity were added. The rate of sedimentation was measured by a sedimentation balance. The flow curves were recorded under electric field up to 2.5 kV/mm. Current density was also measured as a function of shear rate. It was found that the activity of a surfactant depends strongly on its polarity. The lipophylic surfactants stabilized the suspension very well but about 30% decrease of the dynamic yield stress was observed. The current density was reduced as well by almost one order of magnitude. The hydrophylic surfactants hardly stabilized the suspension but increase of yield stress was observed that was not followed by increase of current density. The role of different types of non-ionic surfactants was discussed.

The Effects of Interstitial Content and Annealing on the Flow and Fracture behavior of Polycrystalline ÿ-NiAl

1994 ◽  
Vol 364 ◽  
Author(s):  
M. L. Weaver ◽  
V. Levit ◽  
M. J. Kaufman ◽  
R. D. Noebe
Keyword(s):  
Strain Rate ◽  
Yield Stress ◽  
Work Hardening ◽  
Strain Aging ◽  
Fracture Behavior ◽  
Rate Sensitivity ◽  
Dynamic Strain ◽  
Aging Behavior ◽  
Aging Theories ◽  
Tenfold Increase

AbstractThe strain aging behavior of three polycrystalline NiAl alloys has been investigated at temperatures between 300 and 1200 K. Yield stress plateaus, yield stress transients upon a tenfold increase in strain rate, work hardening peaks, and dips in the strain rate sensitivity (SRS) have been observed between 700 and 800 K. These observations are indicative of dynamic strain aging (DSA) and are discussed in terms of conventional strain aging theories.

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