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Methods for Evaluating Articular Cartilage Quality
Published in Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi, Articular Cartilage, 2017
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi
Friction tests are applied by sliding a probe across the cartilage surface and collecting data for the two forces of interest. This can be done at the macroscale (Jay et al. 2004) or microscale (Coles et al. 2008) level of the joint to determine the frictional characteristics of the sample. An alternative approach is to measure friction using a rheometer, which moves two surfaces rotationally. This device can also measure both the simple and dynamic shear properties of cartilage. Simple shear testing can provide a measure of the shear modulus, G. () τ=Gγ
Polymers
Published in Bryan Ellis, Ray Smith, Polymers, 2008
Mechanical Properties General: Other values of tensile modulus [15], tensile strength [2,5,12,13,22,28,32,34], flexural strength [28] and dynamic elastic modulus [7] have been reported. Shear modulus decreases with increasing temp. [52] Young's modulus reaches a max. at nitrile rubber content of approx. 20% and thereafter decreases [42]. Tensile storage and loss moduli [35] and their variation with temp. [51] have been reported
Materials for Optical Systems
Published in Anees Ahmad, Handbook of Optomechanical Engineering, 2018
The elastic properties of crystalline materials can be described by a 6 × 6 matrix of constants called elastic stiffness constants.12 From these constants, the elastic properties of the material: Young’s modulus E (the elastic modulus in tension), bulk modulus K, modulus of rigidity G (also called shear modulus), and Poissons ratio ν, can be calculated. The constants, and consequently the properties, vary as functions of temperature. Young’s modulus of elasticity is the measure of stiffness or rigidity of a material; the ratio of stress, in the completely elastic region, to the corresponding strain. Bulk modulus is the measure of resistance to change in volume; the ratio of hydrostatic stress to the corresponding change in volume. Shear modulus, or modulus of rigidity, is the ratio of shear stress to the corresponding shear strain under completely elastic conditions. Poisson’s ratio is the ratio of the absolute value of the rate of transverse (lateral) strain to the corresponding axial strain resulting from uniformly distributed axial stress in the elastic deformation region. For isotropic materials, the properties are interrelated by the following equations: () G=E2(1+ν) () K=E3(1−2ν)
Influence of bedding and jointing sand on the shear strength characteristics of Interlocking Paver Blocks – bedding sand interface
Published in International Journal of Pavement Engineering, 2022
Arjun Siva Rathan RT, Sunitha V, Murshida P, Anusudha V
Small scale direct shear test was used to find the shear behaviour of the bedding and jointing sand gradation. The shear box size was of 60 mm *60 mm *25 mm. The test procedure adopted was as per IS 2720 Part 13 (1986). The sand was mixed with an Optimum Moisture Content of 6%. The normal stresses used for the study were 50, 100, 150 and 200 kPa. The readings were recorded digitally using a data logger that is connected with two LVDTs for displacement measurement and a load cell for load measurement. The test was stopped either when the shear displacement reaches 25 mm or when steady state was reached. The shear modulus was calculated by the ratio of shear stress and shear strain considering the slope in the elastic region. The secant modulus was calculated from the derived shear modulus and Poisson’s ratio. The Poisson’s ratio adopted throughout the study was 0.35.
Effect of frequency on cyclic response of marine clay saturated with various pore fluids
Published in International Journal of Geotechnical Engineering, 2021
Swagatika Senapati, Subhadeep Banerjee, Thyagaraj T.
Shear modulus at small strain amplitude was obtained using RC tests for a shear strain range of 0.001–0.1%. The basic principle of these tests is to vibrate the top of the cylindrical soil sample in a torsional mode while bottom portion of the sample is fixed to the pedestal of RC apparatus (ASTM D4015-15 (2017)). To carry out these tests, samples were enclosed in a triaxial chamber and subjected to all-round air pressure. To avoid the diffusion of air through the membrane, the samples were placed in two latex membranes and a layer of silicon grease was applied outside the membranes (Sas, Gabrys, and Szymanski 2017). The RC tests were performed in undrained isotropic conditions. The axial deformations of the samples were measured by the internal Linear Variable Displacement Transducer mounted on the motor placed inside the chamber. The shear modulus is calculated from the shear wave velocity obtained from the tests performed at various confining pressures.
Effect of convection on boundary layer structures in finite thermoelasticity
Published in Journal of Thermal Stresses, 2019
Now, if we fix b = 1, and vary the value of t (or vary the convection coefficient h), we again obtain a boundary layer growth as can be seen in Figure 17. As the value of t (or h) increases, also increases. In fact, when the convection coefficient is increased, more heat is lost through convection, and this causes the temperature θ to drop. This in turn leads to a decrease in the shear modulus μ, as confirmed by Eq. (42). Now, by definition, the shear modulus is the ratio of the shear stress to the shear strain. Since the shear stress remains constant in this case, the shear strain has to increase. This in turn means that the deformation will be greater for higher values of h. Hence, the increase in is justified, as per Eq. (2).