Radial strain

To avoid these complications, we will rely on an empirical approach to estimate the effect of radial strain-rate distribution on degradation yields. 

Fig. 45. Radial strain rate distribution function and its influence on the degradation yield O (r0 orifice radius, r axial distance from the orifice center) C(r2/r0) variation of the strain rate as a function of (r/r0)2 obtained from the reciprocal of the degradation yield curve of a monodisperse polymer fraction (see Fig. 46) C(r/r0) radial distribution of the strain rate in the plane of the orifice, calculated from the function C(r2/rg)...

The gage used to record the strain pulse produced in the rock was a radial strain gage consisting of a resistance-wire sensing element shielded with. Cu and bonded to a short... 

Fijiurc 4. Neutron ditTruclion results showing the disirihution of tlie vnlumc uvcniged (a) radial strain and (h) axi strain as a l unetion of axial position along the interior of the sped men. ... 

If two phases with viscosities and Nf, are constricted at the same radial strain rate Cq, the driving stress differences in the two phases are 6eoAg and 6e()Nf. If the stress states have a common stress the two magnitudes of will differ by 6eo(Ng — Nf,). If is, for example, Ag/lO, the order of... 

Figures 9 and 10 compare radial strains at r=0.685m and 1.45m, respectively. Although large discrepancies still exists among the models, a consistent trend can still be detected between the measured and calculated strains at r=0.685m. At r= 1.45m in the rock, the JNC results of the strain is consistent with the experimental data in trend, and CNSC model results were under-predicted, due to the fixed outside boundary that is too close to the center (radial distance of 3 m).

In addition, four miniature LVDTs have been performed and used (two diametrically opposite pairs) for direct measurement of local radial deformations. These transducers are in contact with the neoprene membrane at middle height of the specimen (figure 2). They are capable of measuring large strains in particular if barrelling of the specimen occurs. Average axial and radial strains are computed from these measurements. 

The last term in this equation is simpfy the velocity, whicdi for a volume flow-rate Q must be AQ/ttD, and the gradient of Z> is clearfy 2 tan a, where a is the half-angle of the conical die chaimel. The rate of radial strain becomes... 

The melt is incompressible to a good approximation hence the axial and radial strain-rates are related ... 

Besides that, compressive force can be manipulated to facilitate cell lysis and collect their cellular components for later cell-based assay. Similarly, Wang et al. fabricated a micromechanical stimulator fliat is capable of providing controlled compressive or tensile strain to the cultured cells in vitro (Fig. 4). Experimental characterization of its PDMS membrane deformation showed that the microdevice can provide —6 % compressive to 25 % tensile radial strain to the cultured cells within the membrane center [6], which allowed simultaneous investigation of both mechanical strains on the same cells. Zhou et al. developed a microchip platform with microchannels that resembles the mechanical environment of small blood vessels in vivo (Fig. 5). They demonstrated that the deformation of the membrane by hydraulic pressure induced cyclic circumferential strains on the adhered mesenchymal stem cells and thus caused significant stmctural and biochemical changes to the cells [7]. 

The specimen fractures circumferentially at a distance (for lightly lubricated low-carbon steel) of 35-40 mm (1.38-1.57 in.) from the hole, where radial strain peaks sharply. The circumferential strain varies gradually from a maximum of 10-20% at the pole to flange or zero at the lock bead. 

Applied electric field [MV/m] Young s modulus [MPa] Dielectric constant Radial strain l%l Elastic energy [J/m l Elastic energy [Jem 3]... 

We can see that when the content of the DOP is increased, the electric field required to actuate the dielectric elastomer is reduced, while the output radial strain is nearly the same, as is shown in Fig. 6.18(a). This occurs because the DOP causes the elastic modulus of the material to decrease, although at the same time there is a decrease in permittivity of the material. In addition, Fig. 6.18(b) illustrates that the contents of the Ti02 at 40 PHR creates a synthetic elastomer with better actuation than the other contents in the same electric field. However, the electric field strength of the material in this case is lower than in the case where the content of the Ti02 is... 

Thirdly, synthetic elastomer was proposed in the effort of finding a new dielectric elastomer material. Comprehensive performance characterization proved that the new material has the highest energy density among the tested materials and the actuation is feasible. Furthermore, by adding different fillers, the properties of the synthetic elastomer material can be adjusted as needed. For instance, different content of DOP and Ti02 show better radial strain of actuation and also increase the elastic energy of the material. 

The ultimate strain in compression was determined experimentally. The results were 1.6% in the x-direction (radial direction at 0°) and 1.82% in the y direction (radial direction at 90°). The ultimate compressive strain at 45° was not determined experimentally. The lowest of the strain values measured in the x- and y direction (1.6%) is taken for the critical radial strain at +45°. The calculated ultimate compressive strength values are presented in Table 5.6. 

Small-diameter arterial grafts using biotextiles 431 Radial strain, therefore, can be expressed thus ... 

The slope s absolute value of linear section on the radial strain—axial strain curve is defined as Poisson s ratio. The data of confining pressure and Poisson s ratio from Table 1 are also plotted in Figure 6. Fitting analysis is conducted as following ... 

The sample preformed radial expansion with a maximum radial strain of -1.14% in the process of loading. After strain-softening, the radid strain changed into -3.86%. However, in the process of unloading, the radial strain went down, when the deviate stress was 0, the radial strain was -3.04%. In the following process the radial strain still went down in a low rate, about -2.89% radial strains... 

---