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The plastic yield and fracture of rubber-modified polystyrene specimens under tensile load have been investigated at room temperature. The experimental procedure consisted of rapidly alternating measurements of transmitted and emitted infrared (IR) radiation from samples under tensile stress. The load-displacement data were simultaneously recorded. Both single-edge-notched and dog-bone-shaped test coupons were studied. In each tensile test run, we observed a significant decrease of material transparency in the IR which occurred near the low yield point. A further increase in material deformation was accompanied by a substantial temperature increase. After material failure, the surface morphology of the test specimens in the vicinity of the crack was examined using atomic force microscopy (AFM). Our results are explained in the context of existing models of material crazing., The toughening properties of rubber added to a glassy polymer in form of small particles, and the ability of such two-component systems to endure large strains, have long been established [...]

The experimental thermal wave images of planar subsurface defects are inverted to determine an enhanced representation of the shape and size of planar subsurface defects. The inversion is effected by an algorithm. The inversion algorithm can also be used in the improvement of the spatial resolution of such defects. The calculations are performed on Macintosh IIfx computers for 128 by 128 pixel images. The inversion time is 1 minute or less.

A method for the measurement of anisotropic thermal diffusivities parallel to a solid sample surface is presented. The mirage effect is the basis of the approach and data from rare earths, ceramics and polymers were analyzed by multiparameter least-squares regression fitting. Variance estimations were used to test the reliability of the measurements. The utility of the mirage measurement technique for materials with very low-diffusivity was established.

Provides information on research carried out which examined the plastic yield and fracture of rubber-modified polystyrene specimens under tensile load. What the experimental procedure consisted of; Analysis of single-edge-notched and dog-bone-shaped test coupons; Results of the research carried out.

Demonstrates the bistable behavior of a vibrating tip near a solid surface. Interpretation of the measurements in terms of perturbed harmonic oscillators.