Johnson Ezenwankwo - Academia.edu (original) (raw)

Papers by Johnson Ezenwankwo

Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engi... more Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engineering. They present many advantages over their synthetic counterparts, including environmental concerns, ease of disposal and reuse, and a high strength-to-weight ratio. Aerospace engineering and other critical engineering sectors are actively turning to NFRPCs for various reasons. Reinforcement in polymeric composites plays a vital role in forming the framework support system upon which the matrix is based; this, in turn, affects the vital mechanical properties of the composite formed and its impact-bearing characteristics. This paper evaluates selected mechanical properties of glass fibre and rayon yarn. The laminates were made so that the thickness was approximately equal. Five tensile tests each were performed following ASTM 3039/D3039-08 standard, and the average of each set is plotted and compared accordingly. The material is weighed, and the fibre and matrix volume fractions are calculated. The standard failure location, area and mode are described with the ASTM standard. A simplified micromechanical analysis is employed to demonstrate the homogenization of the laminate's representative volume element (RVE) to obtain the relevant engineering constants.

Annals of DAAAM for ... & proceedings of the ... International DAAAM Symposium .., 2022

Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engi... more Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engineering. They present many advantages over their synthetic counterparts, including environmental concerns, ease of disposal and reuse, and a high strength-to-weight ratio. Aerospace engineering and other critical engineering sectors are actively turning to NFRPCs for various reasons. Reinforcement in polymeric composites plays a vital role in forming the framework support system upon which the matrix is based; this, in turn, affects the vital mechanical properties of the composite formed and its impact-bearing characteristics. This paper evaluates selected mechanical properties of glass fibre and rayon yarn. The laminates were made so that the thickness was approximately equal. Five tensile tests each were performed following ASTM 3039/D3039-08 standard, and the average of each set is plotted and compared accordingly. The material is weighed, and the fibre and matrix volume fractions are calculated. The standard failure location, area and mode are described with the ASTM standard. A simplified micromechanical analysis is employed to demonstrate the homogenization of the laminate's representative volume element (RVE) to obtain the relevant engineering constants.

This study conducts a comparative evaluation of the performance of modules and the arrays under s... more This study conducts a comparative evaluation of the performance of modules and the arrays under standard test conditions. An equivalent circuit model was developed alongside a computational scheme. The model input data were obtained from the manufacturer’s specification datasheets. They were used to analyse the maximum Fill Factor (FF) and Relative Power Losses (RPL) for Parallel (P), Series (S) and Series-Parallel (SP) configurations. For matching modules, the RPL was insignificant, but for mismatched modules, the parallel configuration (P) and series-parallel (SP) yielded RPL of 1.3 %, while the series configuration (S) produced RPL of 2.6 %. Thus, short circuit defects associated with the P and SP configuration were well below the open circuit defects associated with the series configuration (S). These results clearly show that the large photovoltaic plant needs to be configured with multiple blocks or strings of SP configuration in order to suppress RPL. In addition, the designe...

Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engi... more Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engineering. They present many advantages over their synthetic counterparts, including environmental concerns, ease of disposal and reuse, and a high strength-to-weight ratio. Aerospace engineering and other critical engineering sectors are actively turning to NFRPCs for various reasons. Reinforcement in polymeric composites plays a vital role in forming the framework support system upon which the matrix is based; this, in turn, affects the vital mechanical properties of the composite formed and its impact-bearing characteristics. This paper evaluates selected mechanical properties of glass fibre and rayon yarn. The laminates were made so that the thickness was approximately equal. Five tensile tests each were performed following ASTM 3039/D3039-08 standard, and the average of each set is plotted and compared accordingly. The material is weighed, and the fibre and matrix volume fractions are calculated. The standard failure location, area and mode are described with the ASTM standard. A simplified micromechanical analysis is employed to demonstrate the homogenization of the laminate's representative volume element (RVE) to obtain the relevant engineering constants.

Annals of DAAAM for ... & proceedings of the ... International DAAAM Symposium .., 2022

Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engi... more Natural fibre-reinforced polymer composites (NFRPC) have taken centre stage in materials and engineering. They present many advantages over their synthetic counterparts, including environmental concerns, ease of disposal and reuse, and a high strength-to-weight ratio. Aerospace engineering and other critical engineering sectors are actively turning to NFRPCs for various reasons. Reinforcement in polymeric composites plays a vital role in forming the framework support system upon which the matrix is based; this, in turn, affects the vital mechanical properties of the composite formed and its impact-bearing characteristics. This paper evaluates selected mechanical properties of glass fibre and rayon yarn. The laminates were made so that the thickness was approximately equal. Five tensile tests each were performed following ASTM 3039/D3039-08 standard, and the average of each set is plotted and compared accordingly. The material is weighed, and the fibre and matrix volume fractions are calculated. The standard failure location, area and mode are described with the ASTM standard. A simplified micromechanical analysis is employed to demonstrate the homogenization of the laminate's representative volume element (RVE) to obtain the relevant engineering constants.

This study conducts a comparative evaluation of the performance of modules and the arrays under s... more This study conducts a comparative evaluation of the performance of modules and the arrays under standard test conditions. An equivalent circuit model was developed alongside a computational scheme. The model input data were obtained from the manufacturer’s specification datasheets. They were used to analyse the maximum Fill Factor (FF) and Relative Power Losses (RPL) for Parallel (P), Series (S) and Series-Parallel (SP) configurations. For matching modules, the RPL was insignificant, but for mismatched modules, the parallel configuration (P) and series-parallel (SP) yielded RPL of 1.3 %, while the series configuration (S) produced RPL of 2.6 %. Thus, short circuit defects associated with the P and SP configuration were well below the open circuit defects associated with the series configuration (S). These results clearly show that the large photovoltaic plant needs to be configured with multiple blocks or strings of SP configuration in order to suppress RPL. In addition, the designe...