Stress axial, distribution curves

Figure 4.13 shows the distribution curves of axial stress (a) of composite materials under different interface elastic moduli (.E). 

In the stress analysis of composite materials, the parameters are as follows. The elastic modulus of resin matrix = 1.67 GPa, Poisson s ratio = 0.2, yield strength = 3.5 MPa the elastic modulus of the SiC whisker Ef = 410 GPa, Poisson s ratio Vf = 0.17 the exterior stress o is set to 0.8 Mpa and the volume fraction of the whisker in the composite material is 12.5%. The distribution curve of the axial stress of composite material reinforced with whiskers with different L/D ratios is shown in Figure 4.15. In the figure, Zj(//) stands for the axial... 

Figure 4.15 Distribution curve of axial stress of composite material reinforced by whiskers with different L/D ratios.

As shown in Figure 4.15, with an increase of the L/D ratio of whiskers, the distribution curve of the axial stress of composite material moves upward, and the stress borne by whiskers and resins increases. At the same time, the stress borne by the resin matrix changes only slightly. The L/D ratio of the whisker has a significantly greater impact on the whisker stress than on the resin matrix. 

In summary, a planar interface causes the mean focal position to be significantly deeper that the usually quoted paraxial focal depth, and there is also a large spread in the axial illumination, resulting in a large depth of focus. When the system is coupled to a confocal collection aperture, the collection efficiency curves are relatively complex, with a generally rapid fall in the collection efficiency with focal depth. For a given (large) focal depth, there will be an optimum numerical aperture for efficient collection of Raman intensity. The results of this theory will be compared to measured spectra in Section III, which describes an experiment to map the stress distribution within the diamonds of a diamond anvil cell. 

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