Experimental Determination of the Mechanical Behavior of Glass Fiber Reinforced Polypropylene Composites

AbstractThermoplastic composites have been widely used in structural and engineering applications, due to their high specific strength and stiffness, high strain to failure, better impact strength, shorter processing cycle time, infinite shelf life, and recyclability. This paper discusses the influence of the forming pressure and coupler concentration on the mechanical behavior of glass fiber reinforced polypropylene composite laminates. The Design of Experiments’ (DOE) full factorial approach was adopted for conducting the composite laminate fabrication experiments. The thermoplastic composite laminates were fabricated in a hot compression molding machine, using the film stacking technique. This is an innovative approach to develop thermoplastic composite laminates, using the available low cost raw materials, instead of high end prepreg materials. As per the ASTM standard, the tensile and flexural tests were carried out, in order to evaluate the influence of the parameters on the mechanical behavior of the composite laminates. The Tensile and flexural strengths of the thermoplastic composite laminates were the responses measured to identify the most influencing parameter. The experimental results show that the increase in forming pressure and coupler concentration initially increases both the mechanical properties, and then decreases the properties of the composite laminates. Compared to the coupler concentration, the forming pressure greatly improves both the tensile and flexural properties. Using the Scanning Electron Microscope (SEM), a morphological analysis was carried out to observe the bonding between the matrix and reinforcement

Mechanical and Tribological Behaviour of Treated and Untreated Moringa Oleifera Pods Fiber Reinforced Epoxy Polymer Composite for Packaging Applications

Researchers now focus on the use of natural fiber polymer composites materials for packing applications. This attention is due to their low cost and renewable characteristics. Fabrication of composites with the use of renewable resources has many benefits of alternating from an appropriate management and reduction in industrial wastages, ecofriendly behaviour to cost effectiveness. The artificial fibers in packing industries can be replaced by natural fibers in the areas where stiffness and high strength are not the primary requirement. In the last decade the use of Natural fibers in the place of artificial fibers for reinforcements in epoxy resin matrix ratio has been gaining momentum. In this work, the different quantity of treated and untreated Moringa pods Oleifera fiber were reinforced LV5012 CNSL hardener with LY556 Epoxy by using hand lay-up technique. Mechanical behaviour (tensile, flexural and impact), Tribological and water absorption behaviour are evaluated. The microstructural analysis of fabricated composite was done by using Scanning Electron Microscope (SEM) to analysis the fiber strength, internal fiber failure, cracks and interfacial properties of the fractured surfaces. Based on the results, treated MOPF polymer composites have found better mechanical, wear and water absorption properties to be used for packaging applications compared with untreated MOPF polymer composites

Modelling and Optimization of Friction Stir Welding Parameters for Dissimilar Aluminium Alloys Using RSM

AbstractThe friction stir welding (FSW) process parameters play a major role in deciding the joint characteristics. Response Surface methodology (RSM) was used to predict the ultimate tensile strength, yield strength and displacement of friction stir welded (AA6061-T6 and AA7075-T6) aluminium alloy. The experiments were conducted based on three factors namely rotational speed, welding speed and axial force. The empirical relationships were developed by response surface methodology (RSM) incorporating FSW tool parameters (rotational speed, welding speed, axial forceand process parameterstensile strength, Yield strength (YS) and Displacement (DP) by Central composite design (CCD) technique

Hydrodynamic cavitation for sonochemical effects

A comparative study of hydrodynamic and acoustic cavitation has been made on the basis of numerical solutions of the Rayleigh-Plesset equation. The bubble/cavity behaviour has been studied under both acoustic and hydrodynamic cavitation conditions. The effect of varying pressure fields on the collapse of the cavity (sinusoidal for acoustic and linear for hydrodynamic) and also on the latter's dynamic behaviour has been studied. The variations of parameters such as initial cavity size, intensity of the acoustic field and irradiation frequency in the case of acoustic cavitation, and initial cavity size, final recovery pressure and time for pressure recovery in the case of hydrodynamic cavitation, have been found to have significant effects on cavity/bubble dynamics. The simulations reveal that the bubble/cavity collapsing behaviour in the case of hydrodynamic cavitation is accompanied by a large number of pressure pulses of relatively smaller magnitude, compared with just one or two pulses under acoustic cavitation. It has been shown that hydrodynamic cavitation offers greater control over operating parameters and the resultant cavitation intensity. Finally, a brief summary of the experimental results on the oxidation of aqueous KI solution with a hydrodynamic cavitation set-up is given which supports the conclusion of this numerical study. The methodology presented allows one to manipulate and optimise of specific process, either physical or chemical

Effect of grain refinement on superplastic forming of magnesium alloy AZ31 under three different conditions using rectangular die

In this work, the rectangular die is fabricated and superplastic forming of the magnesium alloy is carried out. The AZ31 alloy is taken under three different conditions such as base sample (without processing), rolled sample and shot peened sample. The die design is exported using a CAD model and subsequent fabrication process is performed. The superplastic deformation property of the magnesium alloy is explored through the blow forming method. Inert gas (argon) is passed under high pressure with temperature (250 °C) to blow the metal into a rectangular shape. Finally, the formed component is subjected to microstructural and mechanical studies