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The durability of a machine structure is based on its mechanical performance through its entire service life. To avoid structural failures in machines, it is a standard design practice that machines be analyzed based on the types of loading (static and fatigue) associated with it in order to design safe and dependable machine structures. These types of analyses are performed with the purpose of estimating the behavior of the mechanical parts under specific operational conditions. The aim of this research is to investigate the effect of different loading to the maximum load on the redesigned shafts of an existing cassava peeling machine capable of peeling at least one (10) tons of   cassava tubers with different weight, size or shape per day  to ascertain the effects on the bending moment, shear force, deflection angle, shear stress and bending stress, and evaluate if there is need to reduce or increase the thickness of the shafts to a standard considered to be safe and economical. The three shafts of the cassava peeling machine have been carefully analyzed to check for their fatigue life under different loading conditions. From the analysis, with stress values of 48.640MPa, 49.1289MPa, 3.06089MPa and shaft diameter values of 34.6799mm, 34.7955mm, 13.7941mm evaluated from the reduced stress diagrams and ideal diameter diagrams for abrasive cylinder shaft, peeling cylinder shaft, and retainer shaft respectively, gave positive results because none of stress values were greater than reduced stresses (calculated stress value from Tresca’s theory) on the respective shafts. Therefore, a standard steel shaft of 35mm diameter is appropriate for manufacturing of the machine and also safe and economical.

This paper focuses on the application of Taguchi Robust Design to determine the optimum tensile strength of Ukam-Plant Fibre Reinforced CNSL Composite using indigenous or locally sourced vegetable or plant based natural fibres (Ukam-plant fibres) that are Lignocellulose as potential raw material. Tensile tests were conducted on the replicated samples of Ukam-Plant Fibre Reinforced CNSL Composite to obtain the optimum properties. Hounsfield Mosanto Tensometer, a universal testing machine was used to conduct tensile tests to determine the control factor levels quality characteristics considered necessary to optimize the mechanical property being investigated. Methodology of traditional and experimental design approach of Taguchi was used for the larger the better to obtain the highest signal to noise ratio (SN ratio) for the quality characteristic being investigated and also to correlate the control factors (fibre condition i.e. untreated, silane treated and alkaline treated, volume fraction and fibre size). Minitab 16 software was used for statistical analysis to fine-tune conclusions and produce quantitative estimates. The optimum settings were as follows: alkaline treatment, volume fraction of 50%, and 50mm of fibre size which resulted in 18.69MPa optimum tensile strength. The experimental results obtained agreed satisfactorily with the Minitab 16 software predictions. The mechanical property studied revealed that composite depends significantly on the reinforcement combination of control parameters.

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