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In this paper, we present the results of finite element analysis (FEA) performed to investigate nature of stress and their distribution at optimum point along the two turning tables of a micro-controller based versatile machine tool desktop learning module. Commercial Autodesk Inventor was used to create both three-dimensional (3-D) and 2-D models as well as performing simulation. Dynamics simulation generated the motion load expected to act on the tables when used for real-life operation which were in turn used to perform FEA. The motion of the dc servo motor driving the tables and other parts of the module is designed to be controlled by programmable chips. Before creating FEA simulation for the tables, numerical divergence were prevented by varying the mesh settings to obtain the settings at which the results of the analyses converges which was obtained at 0.03 average element size and 0.04 minimum element size. Finite element analysis carried out on the tables shows that aluminium alloy 4032-T6 chosen will serve in the fabrication of physical prototype. FEA revealed the nature and level of stresses that will be experienced on the tables, it also revealed region where these stresses will concentrate on them. The analysis also estimated the expected weight of the turning tables 1&2 to be 1.23536 to 0.257182 Kg respectively and show that the minimum factor of safety was constantly 15 ul within the tables which shows that they will not fail during operation. [ABSTRACT FROM AUTHOR]

Kenaf and Sisal fibres generally have some advantages such as their eco-friendly nature, biodegradability, renewable nature are lighter than synthetic fibres. The aim of this study is to evaluate the potentials of using weaved and un-weaved indigenous sisal and kenaf fibre to reinforce polyester resin based on the physical and mechanical properties obtainable from the resulted composites. The composites materials and sampling were prepared in the laboratory by introducing 10g of the fibre which is about 20% fibre content into the matrix using 1) the hand lay-up method for un-weaved samples, and 2) coating method for weaved samples, with the aid of a mechanical roller. Samples were prepared based on ASTM: D3039-08 for tensile test. Properties such as tensile strength and modulus, hardness, impact strength, flexural strength, density and water absorption were analysed. The results of the characterization showed that density of the material reduced on introduction of fibres while the rate at which the material absorbs water increased though sisal fibre reinforced materials absorbed more. This was due to the void content of composite which increased due to the fibre inclusion within the composite. The results also show that the flexural strength of the composite material developed increased with fibre introduction, though weaved fibre possesses more strength than un-weaved ones. Finally, no particular composition possesses optimum value for all the properties measured. [ABSTRACT FROM AUTHOR]

In this work, kaolin based ceramics using styrofoam, sawdust, and powdery high density polyethylene as pore formers were experimentally investigated. Prior to batch formulations, the kaolinite used was wet beneficiated. This was followed by mixing starting materials with pore formers, producing green bodies which were then uni-axially compacted into standard sample dimensions and fired at various sintering temperatures of 850°C, 1000°C and 1150°C for 2 hours in a furnace. The physical and mechanical properties of the sintered samples were investigated and the generated data analysed. It was observed that the apparent porosity and water absorption of the samples decreased with increased sintering temperature, while the bulk density, apparent density and cold crushing strength of the samples increased with increased sintering temperature. It was concluded that the samples which were sintered at 850°C with 5% wt pore former of powdery high density polyethylene gave the optimum properties in terms of the porosity and mechanical strength of the samples. [ABSTRACT FROM AUTHOR]