Analysis of Circular Hole and Thermal Cycle Effects on the Mechanical Properties in Multi-Layer Polymer Composite Reinforced with Nanoparticles

In this research, the analysis of the effects of circular hole and thermal cycle fatigue on the mechanical properties in multi-layer polymer composite reinforced with nanoparticles are investigated. First, multi-walled carbon nanotubes with 0.1% weight fraction of nanoparticles are added to the epoxy resin ML506. The. In order to homogenize particle in the resin, it is mixed with a magnetic stirrer for 30 minutes. The material is placed in an ultrasonic device for 40 minutes to homogenize the resin and nanoparticle completely. The resin reinforced with glass fibers constitute symmetric cross ply laminates stacking sequence [02/902]s, and nanocomposite samples are made with hand layup method. In this study, open-hole specimens with diameter of 2 and 4mm are investigated. To study the thermal cycles, nanocomposite samples of 3 levels of thermal cycles including 0, 180, and 360 cycles were investigated. The samples are exposed to a temperature range of 0 to 100oC. After that, the specimens undergo tensile testing. Using the tensile test, the modulus of elasticity and tensile strength are compared for the different thermal cycles and the diameter of the holes. By increasing the number of thermal cycles, the tensile strengths of nanocomposite samples are not significantly changed. Also, with increasing the diameter of the hole, the tensile strength is decreased. The elasticity modulus with increasing thermal cycles for all specimens have been minimal changes. Also, a linear regression model was developed, using MINITAB software for strength and elastic modulus in terms of number of thermal cycles and diameter to width ratio.