Uniaxial compressive response

The uniaxial compressive response of the four materials was examined using cylindrical specimens with a diameter of 10mm and a height of 15 mm. The compression testing was... 

The stress-strain response of ideal networks under uniaxial compression or extension is characterized as follows ... 

E.B. Bagley, D.D. Christianson and W.J. Wolf, Frictional Effects in Compressional Deformation of Gelatin and Starch Gels and Comparison of Material Response in Simple Shear, Torsion and Lubricated Uniaxial Compression, J. Rheol., 29 103-108 (1985). 

We have found that the microstructural changes and stress response of our model protein monolayer to uniaxial compression is very sensitive to the nature of the particle-particle interactions. The structural differences of the same systems at equilibrium are much less obvious. These findings suggest that the validation of simulation models by comparing their qualitative behavior under large-deformation compression (expansion) with the experimental results is likely to be more powerful than the comparison of just the equilibrium properties of the adsorbed films. 

The finely crystalline zeolitic matrix of tuffs cements the other non zeolitic particles and is responsible for the overall mechanical properties of the material. The compactness and the consequent physical-mechanical properties are somewhat variable as they are function of various parameters, such as mineral composition, tuff genesis, and original conditions of the deposit, especially as regards looseness of the parent material, grain size distribution, and others. Table 3 summarizes some data on unit weight, y, porosity, P, and uniaxial compressive strength, a, of a few tuff samples and other stone materials. 

Fig. 6.7 A comparison of the nominal stress, t, vs. the stretch response of neoprene in uniaxial compression and plane-strain compression at T = 293 K of the eight-chain model and data from experiments (from Arruda and Boyce (1993) courtesy of Elsevier).

Figure 9.28 shows the stress train eurves of a whole eomplement of deformation modes with all flow stresses normalized with tq, giving the dependenees of e/ro, the normalized global equivalent deviatorie shear resistances, on Se, the global equivalent plastic strain. The predieted stress strain eurve for plane-strain eompression agrees well with the data points of the Gal ski et al. experiments. We note that the predicted response for uniaxial tension is also elose to the predietion for plane-strain compression and that these two, as examples of irrotational flow, differ markedly from the simple shear results and also from the experimental results and the predictions for uniaxial compression, in comparison with the experimental results of Bartczak et al. (1992b). 

Cassidy JJ, Hiltner A, Baer E (1990) The response of the hierarchical structure of the intervertebral-disk to uniaxial compression. J Mater Sci Mater Med 1 69-80... 

The challenges inherent in the measurement of stress-strain response of thin film materials by means of direct tensile testing are commonly more than offset by the distinct advantage that properties characterizing deformation resistance of the material in the plastic range can be determined under isothermal conditions for a relatively simple state of stress on the specimen. However, these techniques are not readily amenable to modifications that can accommodate uniaxial compression, simple shear stress, equi-biaxial stress or states stress on the specimen. As a result, it is difficult to draw conclusions concerning the dependence of plastic response on stress path history. It is noted that results for some cyclic tension-compression experiments were reported by Hommel et al. (1999). 

Previous work indicates that the indentation response of mica glass-ceramic materials is a function of the macroscopic uniaxial compressive yield stress, Y and a strain-hardening characteristic. A range of behavior, from quasi-ductile to nominally brittle, could be attained by simply varying the size and shape of the grains through... 

Casern, D. T. (2008) Mechanical Response of an AI-PTFE Composite to Uniaxial Compression over a Range of Strain Rates and Temperatures. ARL-TR-4560, Army Research Laboratory, Aberdeen Proving Ground,... 

UHMWPE specimens subjected to very small strains, while exploration of hyperelasticity theory led to the conclusion that it is often safer to use a more sophisticated constitutive model when modeling UHMWPE. The use of linear viscoelasticity theory led to a reasonable prediction for the response of the material during a uniaxial compression test however, even small changes to the strain rate rendered the previously identified material parameters unsatisfactory. Isotropic J2-plasticity theory provided excellent predictions under monotonic, uniaxial, constant-strain rate, constant-temperature conditions, but it was unable to predict reasonable results for a cyclic test. The augmented Hybrid Model was capable of predicting the behavior of UHMWPE during a uniaxial tension test, a cyclic uniaxial fully... 

One important issue in dealing with the nonlinear viscoelastic response of materials is the amount of data needed to determine the material parameters in the models. As noted above, even the general finite elasticity theory requires significant work to obtain the material parameters over the full three-dimensional deformation space. This is one reason that the VL framework is so attractive, when it works. Therefore, it is of interest to investigate whether or not the model can be extended to include compressibility. Pesce and McKenna (146) performed torsional tests on polycarbonate as described above. They then asked whether the VL function could be used to predict the tension and compression responses of the material. An important assumption in their approach was that the VL function determined from the torsional measurements using equations 45, 46, 47, 48, 49, 50, 51 (described immediately above) could be used to predict uniaxial data. When the incompressible equations 50 were applied to try to estimate the uniaxial stress-deformation data (isochronal), these equations did not work. However,... 

There are two major mechanisms by which glassy polymers yield in response to stress. Shear deformation is a localized phenomenon that may appear as shear bands. When a polystyrene cube is uniaxially compressed, the bands appear at a... 

Uniaxial tension testing with superposed hydrostatic pressure has been described by Vernon (111) and Surland et al. (103). Such tests provide response and failure measurements in the triaxial compression or tension-compression-compression octants. 

In addition to the compression loading, uniaxial extension of entangled PDMS chains have been investigated by pulling a small portion of the material and measuring elastic response before the rupture happens [419]. The multiple ruptures observed in the force-distance curves (Fig. 43) have been interpreted as fractures of an entangled network of PDMS chains formed between the tip and the silica grafted surface. At small deformations, also the capillary forces were shown to contribute in the force. The elastic part of the curves was described us-... 

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