Swelling stress, differential

The anomalous increase of the water uptake observed in Fig. 10 when approaching equilibrium at 60 °C has been associated to the damage. The abrupt upturn of the sorption curve may be explained considering a possible crazing of the low crosslinked internodular matrix induced by the differential swelling stresses that can arise, at high water contents, between areas of different crosslinking density. 

Protein swelling Differential stress due to rapid dehydration Changes in lipid fluidity... 

Recorded normal stresses in borehole SG2 (CT Oo. Or), are reproduced, together with predictions of several teams in Figure 26a,b,c. Measuring cells were located at radial distances of 2.59 m, 2.97 m and 3.25 m respectively. The observed increase in total stress is due to differential rock dilation effects induced by the varying temperature field and by the increasing swelling pressure at the tunnel wall. 

The load or force that causes stress around a discontinuity may be applied externally to a material or structure. More often, in bonded joints the force arises from differential shrinkage and swelling of the bonded members or particles. In adhesive joints and most wood products, forces tending to cleave the joint (mode I loading) are of primary importance. Sliding shear (mode II) and torsional shearing (mode III) forces are less important. However, most wood joints experience a combination of mode I with either mode II or mode III shear. 

Qualitative explanations for the hysteresis in sorption for cellulosic materials have been advanced. Urquhart [23] hypothesized that hysteresis could be caused by a differential availability of hydroxyl groups in cellulose during the adsorption and desorption branches of the RH cycle. A second explanation for hysteresis stems from the observed plasticity of the cellulose gels, which swells upon adsorption. Desorption results in some irreversible (plastic) deformation, which results in a higher moisture content of the structure as compared to the adsorption process. His theory postulated that the lost work during a stress strain cycle is equal to the lost work represented by the hysteresis loop between two relative humidity levels. 

An inventor took his new PMMA kitchen bowl from the dishwasher, which had just completed its duties. The bowl shattered when he poured a bottle of gin into it. Subsequent investigation showed that the PMMA absorbed about 2 % of water under hot, wet conditions in the dishwasher, and that only the surface layers dried out during the dry heating stage. The surface was therefore under tensile stress due to differential swelling when the ethanol exhibited its powers as a solvent crazing agent. 

Sulfonated membranes take up liquid water, which enables them to conduct protons, but which also results in swelling of the membrane. Hence, stresses occurring during temperature and humidity cycling [169,170] can lead to mechanical failure of the membrane. Mechanical failure can also result from nonuniform contact pressure [171], high differential initial gas pressure over the membrane, and punctures as well as fatigue from stresses occurring. 

Some of the desired properties such as the electrical performance are relatively easy to measure and interpret. However, thermomechanical characteristics, such as dimensional stability and warp and twist, depend upon a number of interacting complex physical and chemical properties including differential thermal expansion, swelling and stresses built in during cure or lamination. They are therefore more difficult to predict or quantify in a precise manner from simple measurements of basic properties. 

When a fuel pin is first placed in the reactor the fuel is subjected to a large radial temperature gradient. If the fuel is coherent, large thermal stresses are produced. The solution of this problem enables the pellet crack distributions to be described and can also be extended to include the effects of differential fuel swelling, and, by allowing Poisson s ratio to approach 0.5, include the creep behavior. 

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