Deformation profiles and microscopic dynamics of complex fluids during oscillatory shear experiments

Abstract In this paper, the linear and non-linear rheological properties of estuarine cohesive sediments were investigated. The density of the sediments has been determined by pycnometry. Creep and oscillatory shear measurements have been performed in order to determine i) the transitions in mechanical response to creep and oscillatory shear and ii) the material properties of these natural fluids as a function of their density. For all samples tested, four different rheological transitions have been determined and all material properties have been shown to be satisfactorily fitted by exponential functions of the density.

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Characterising shear-induced dynamics in flowing complex fluids using differential dynamic microscopy

Soft Matter ◽

10.1039/d1sm01094h ◽

2021 ◽

Vol 17 (39) ◽

pp. 8838-8849

Author(s):

James A. Richards ◽

Vincent A. Martinez ◽

Jochen Arlt

Keyword(s):

Shear Flows ◽

Complex Fluids ◽

Steady Shear ◽

Concentrated Emulsion ◽

Microscopic Dynamics

We show how DDM measures microscopic dynamics in oscillatory or steady shear flows and use the technique to explore the yielding of a concentrated emulsion.

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The mechanical basis of Drosophila audition

Journal of Experimental Biology ◽

10.1242/jeb.205.9.1199 ◽

2002 ◽

Vol 205 (9) ◽

pp. 1199-1208 ◽

Cited By ~ 7

Author(s):

Martin C. Göpfert ◽

Daniel Robert

Keyword(s):

Mechanical Response ◽

Dynamic Range ◽

Near Field ◽

Sense Organ ◽

Field Measurements ◽

Longitudinal Axis ◽

Acoustic Energy ◽

Linear Effect ◽

Response Characteristics ◽

Non Linear

SUMMARY In Drosophila melanogaster, antennal hearing organs mediate the detection of conspecific songs. Combining laser Doppler vibrometry, acoustic near-field measurements and anatomical analysis, we have investigated the first steps in Drosophila audition, i.e. the conversion of acoustic energy into mechanical vibrations and the subsequent transmission of vibrations to the auditory receptors in the base of the antenna. Examination of the mechanical responses of the antennal structures established that the distal antennal parts (the funiculus and the arista) together constitute a mechanical entity, the sound receiver. Unconventionally, this receiver is asymmetric, resulting in an unusual, rotatory pattern of vibration; in the presence of sound, the arista and the funiculus together rotate about the longitudinal axis of the latter. According to the mechanical response characteristics, the antennal receiver represents a moderately damped simple harmonic oscillator. The receiver's resonance frequency increases continuously with the stimulus intensity, demonstrating the presence of a non-linear stiffness that may be introduced by the auditory sense organ. This surprising,non-linear effect is relevant for close-range acoustic communication in Drosophila; by improving antennal sensitivity at low song intensities and reducing sensitivity when intensity is high, it brings about dynamic range compression in the fly's auditory system.

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Effective mechanical response of non-linear heterogeneous materials comprising bimodular phases

European Journal of Mechanics - A/Solids ◽

10.1016/j.euromechsol.2020.103962 ◽

2020 ◽

Vol 81 ◽

pp. 103962

Author(s):

Elisabetta Monaldo ◽

Stella Brach ◽

Djimédo Kondo ◽

Giuseppe Vairo

Keyword(s):

Mechanical Response ◽

Heterogeneous Materials ◽

Non Linear

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Non-linear mechanical response of various metals. VII. Stress-strain relations for simple compression, tension and torsion

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/14/7/017 ◽

1981 ◽

Vol 14 (7) ◽

pp. 1293-1306 ◽

Cited By ~ 2

Author(s):

E W Billington

Keyword(s):

Mechanical Response ◽

Stress Strain ◽

Non Linear ◽

Simple Compression

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Mechanical Behavior of a Solid Composite Propellant during Motor Ignition

Rubber Chemistry and Technology ◽

10.5254/1.3538726 ◽

1995 ◽

Vol 68 (1) ◽

pp. 146-157 ◽

Cited By ~ 5

Author(s):

Y. Traissac ◽

J. Ninous ◽

R. Neviere ◽

J. Pouyet

Keyword(s):

Hydrostatic Pressure ◽

Simple Shear ◽

Atmospheric Pressure ◽

Mechanical Response ◽

Uniaxial Tensile ◽

Strain Rates ◽

Shear Tests ◽

Composite Propellant ◽

Pressure Sensitive ◽

Ultimate Properties

Abstract In order to understand the behavior of composite propellants during motor ignition, a particular study about mechanical and ultimate properties of a Hydroxy-Terminated Polybutadiene (HTPB) filled propellant under superimposed hydrostatic pressure was carried out. The mechanical response of the propellant was obtained for uniaxial tensile and simple shear tests at various temperatures, strain rates and superimposed pressures from atmospheric pressure to 15 MPa. The experimentally observed ultimate properties were found to be strongly pressure sensitive and the data were formalized in a specific stress failure criterion.

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Differences between stress and strain control in the non-linear behavior of complex fluids

Rheologica Acta ◽

10.1007/s00397-010-0450-0 ◽

2010 ◽

Vol 49 (9) ◽

pp. 909-930 ◽

Cited By ~ 77

Author(s):

Jörg Läuger ◽

Heiko Stettin

Keyword(s):

Complex Fluids ◽

Stress And Strain ◽

Strain Control ◽

Linear Behavior ◽

Non Linear

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Spectral Response of Stationary Jack-Up Platforms Loaded by Sea Waves and Wind using Perturbation Method

Polish Maritime Research ◽

10.2478/pomr-2021-0049 ◽

2021 ◽

Vol 28 (4) ◽

pp. 53-62

Author(s):

Bogdan Rozmarynowski ◽

Wojciech Jesien

Keyword(s):

Dynamic System ◽

Perturbation Method ◽

Mechanical Response ◽

Spectral Response ◽

Wave Structure ◽

Stationary Condition ◽

Offshore Platforms ◽

Sea Waves ◽

Non Linear ◽

Jack Up

Abstract The paper addresses non-linear vibrations of offshore jack-up drilling platforms loaded by sea waves and wind in their stationary condition using the perturbation method. Non-linearity of dynamic equations of motion for fixed offshore platforms yields from two factors. The first is load excitation generating non-linear velocity coupling in a dynamic system. This coupling is inherent in the modified Morison equation, involving the excitation function in the form of the sum of the inertial and velocity forces of sea waves, taking into account relative wave–structure kinematics. Moreover, the wind acting on the exciting side causes similar effects. The second source is the subsoil–structure interaction problem, modelled by a system of springs and dashpots that yields stochastic non-linearity of the dynamic system. The matrix equations of structural motion in FEM terms are set up. The perturbation method is adopted to determine the mechanical response of the system, making it possible to determine response spectra of the first and the second approximations for displacements and internal forces of the platform. The paper is the continuation of research detailed in the paper [1]. It is assumed, that the fluctuation parts of the dynamic loading forces are in line with the direction of sea wave propagation. Sea current and lift forces effects are neglected in this study. A numerical example refers to structural data of the Baltic drilling platform in the stationary configuration, i.e. when three legs support the deck above the seawater level.

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Analytical Study of Elastic-Plastic Fracture in the Crack-Lap Shear Multilayered Beam Configuration

Journal of Theoretical and Applied Mechanics ◽

10.2478/jtam-2018-0023 ◽

2018 ◽

Vol 48 (4) ◽

pp. 61-77

Author(s):

Victor Rizov

Keyword(s):

Analytical Study ◽

Mechanical Response ◽

Fracture Behaviour ◽

Stress Strain ◽

Lap Shear ◽

Linear Fracture ◽

Strain Relation ◽

Stress Strain Relation ◽

Non Linear ◽

Multilayered Beam

Abstract This paper reports an analytical study of delamination fracture in the Crack-Lap Shear (CLS) multilayered beam configuration with taking into account the material non-linearity. A delamination crack was located arbitrary along the beam height. It was assumed that the CLS mechanical response can be described by using a power-law stress-strain relation. It should be mentioned that each layer may have different material constants in the stress-strain relation. Besides, the thickness of each layer may be different. The classical beam theory was applied in the present study. The non-linear fracture behaviour was analyzed by the J-integral. Analytical solutions of the J-integral were obtained for homogeneous as well as for multilayered CLS beams. In order to verify the solutions obtained, analyses of the strain energy release rate were developed with considering material non-linearity. Material properties and crack location effects on the non-linear fracture behaviour were investigated. The analysis revealed that the J-integral value increases when the material non-linearity is taken into account. It was found also that the J-integral value decreases with increasing the lower crack arm thickness. The approach developed here is very convenient for parametric fracture analyses. The solutions derived can be used for optimization of the CLS multilayered beams with respect to their fracture performance.

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