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This paper evaluates the effect of two experimental parameters, namely microvise blade geometry and blade separation, on the scatter in measured interfacial strength in microbond experiments, with the help of two-dimensional (2D) and three-dimensional (3D) finite element models. The 3D model better captures the ‘exact’ loading nature of the problem as compared to the 2D model but it is computationally intensive. Stress distributions obtained by finite element analysis are compared with those from the shear-lag model often used to analyze microbond experiments. This comparison determines the effectiveness of using shear-lag analysis in microbond experiments and for explaining the reasons for commonly observed data scatter.

This experimental investigation reports on the durability of epoxy-clay nanocomposites upon exposure to multiple environments. Nanocomposites are fabricated by mixing the clay particles using various combinations of mechanical mixing, high-shear dispersion, and ultrasonication. Clay morphology is characterized using X-ray diffraction and transmission electron microscopy. Specimens of both neat epoxy and the epoxy-clay nanocomposite are subjected to two environmental conditions: combined UV radiation and condensation on 3-hour repeat cycle and constant temperature-humidity, for a total exposure duration of 4770 hours. The presence of nanoscale clay inhibits moisture uptake, as demonstrated by exposure to constant temperature-humidity. Nonetheless, both materials lose mass under exposure to combined UV radiation and condensation due to the erosion of epoxy by a synergistic process. Surprisingly, the epoxy-clay specimens exhibit greater mass loss, as compared to neat epoxy. Mechanical testing shows that either environment does not significant affect the flexure modulus of either material. On the other hand, both materials undergo degradation in flexural strength when exposed to either environment. However, the epoxy-clay nanocomposite retains 37% more flexure strength than the neat epoxy after 4072 hours of exposure.

Vacuum-assisted resin transfer molding (VARTM) has been used to fabricate engineered composite materials from postconsumer carpet waste. The process is unique and applicable to any type of carpet. This method utilizes the three-dimensional material architecture of carpet to result in composites with improved mechanical properties, as compared to other recycled carpet-based materials. The technique can be used to make laminated structures for load-bearing applications. As a result, this can lead to the recycling of waste carpet with the potential of reduced environmental impact. The potential applications of these composites include low-cost containers, civil infrastructure

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