Mathematical models for evaluating the influence of degradation on the tensile and flexural properties of palm kernel shell ash/epoxy composites

Abstract

This work developed mathematical models for predicting the influence of degradation on the mechanical properties of palm kernel shell ash (PKSA) reinforced epoxy composites. The composites after production were divided into three parts, one part was used as the control samples while the other two parts were buried in soil and water, respectively for 90 d after which experimental tests were carried out based on the ASTM standards. The experimental data from the tensile and flexural properties were analyzed and modeled using a multiple regression analysis to generate higher-order polynomial equations solved to obtain the predicted values. Comparison and validation of the models was carried out through the use of data analysis (T-test and Perron-Frobenious theorem). The result gotten revealed that the tensile properties could be accurately predicted by the developed models at reinforcement of (≤8 w/% and ≥16 w/% for normal), (≤8 w/% for soil) and (≤8 w/% for water) while flexural strength was accurately predicted at reinforcement of (≤6 w/% and ≥18 w/% for normal), (≤6 w/% and ≥14 w/% for soil) and (≥ 1 w/% for water).