Shear strength under pressure

Plastic Forming. A plastic ceramic body deforms iaelastically without mpture under a compressive load that produces a shear stress ia excess of the shear strength of the body. Plastic forming processes (38,40—42,54—57) iavolve elastic—plastic behavior, whereby measurable elastic respoase occurs before and after plastic yielding. At pressures above the shear strength, the body deforms plastically by shear flow. 

In the perfectly elastic, perfectly plastic models, the high pressure compressibility can be approximated from static high pressure experiments or from high-order elastic constant measurements. Based on an estimate of strength, the stress-volume relation under uniaxial strain conditions appropriate for shock compression can be constructed. Inversely, and more typically, strength corrections can be applied to shock data to remove the shear strength component. The stress-volume relation is composed of the isotropic (hydrostatic) stress to which a component of shear stress appropriate to the... 

Acoustic cavitation (AC), formation of pulsating cavities in a fluid, occurs when a powerful ultrasound is applied to a non-viscous fluid. The cavities are formed when the variable acoustic pressure in the rarefaction phase exceeds the cohesive strength of the fluid. Under acoustic treatment (AT), cavities grow to resonance dimensions conditioned by frequency, amplitude of oscillations, stiffness properties and external conditions, and start to pulsate synchronously (self-consistently) with acoustic pressure in the medium. The cavities undergo significant strains (compared to their dimensions) and their size decreases under compression up to collapsing. This nonlinear behavior determines the active, destructional character of the cavities near which significant shear velocities, local pressure and temperature bursts occur in the fluid. Cavitation determines the specific character of acoustic treatment of the fluid and effects upon objects resident in the fluid, as well as all consequences of these effects. 

To determine the changes in the shear strength of the filter cakes of dolomite and quartz experiments have been done in the seven different saturation degree under three different pressures. The results are given in Figure 5 and 6 for dolomite and quartz, respectively. 

Merkel S., Jephcoat A. P., Shu J., Mao H.-K., Gillet P., and Hemley R. J. (2002) Equation of state, elasticity, and shear strength of pyrite under high pressure. Phys. Chem. Mineral. 29, 1-9. 

Within the cylindrical hole serving as a sample chamber, a suitable, normally liquid, pressure transmitting medium is used to provide hydrostatic pressure conditions. However, soft salts like CsCl with low shear strength have also been employed in some experiments. One of the conditions for a suitable pressure medium is that even under irradiation by X-rays it does not undergo chemical reactions with the investigated sample. 

A solution is developed for the build-up, steady and post-arrest dissipative pore fluid pressure fields that develop around a penetrometer that self-embeds from freefall into the seabed. Arrest from freefall considers deceleration under undrained conditions in a purely cohesive soil, with constant shear strength with depth. Consider a lance falling through the water column that has reached terminal velocity, Uo, and subsequently impacts the soft sediments of the seabed, as illustrated in Figure 5. The non-dimensional pressure, Pd, may be used to define the build-up of pressure following the impact of the penetrometer with the surface of the seabed. The penetrometer impacts the seabed at velocity Uo, represented in dimensionless magnitude as Ud, and decelerates to arrest. Non-dimensional pressures are plotted as the product PdXd, since it is known that the peak pressures, sh-... 

Pressure-sensitive adhesives (PSAs) are used in various forms for packaging, medical and masking tapes and labels. PSAs are viscoelastic materials that exhibit sohd-like and liquid-like behavior so that their performance can be evaluated by tack (the capability of a PSA to adhere instantly under light pressure), peel strength (the tensile force required to remove a PSA) and shear strength (flow resistance) [1, 2]. 

Component B is sprayed as a very thin film on clean (or oily) steel and allowed to evaporate for 2 minutes. Component A is applied to the other steel substrate in a film thickness of 3-10 mils. The two surfaces are mated under contact pressure. Shear strengths of 3200 psi were achieved, with peel strengths on the order of... 

Using experimental values of maximum excess pore pressure developed and Equation 9.7, they found that the maximum reduction in undrained shear strength of the soil would be on the order of 35% under repeated load application. 

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