Comparison of theoretical and experimental maximum stress of polyester composite and aligned sisal fibers

Natural fibers such as sisal, jute, and curauá have lengths that allow the production of aligned specimens. In the case of sisal fiber, this length varies from 700 to 1100 mm, making it possible to manufacture composites with lengths that fit the dimensions provided for in specific standards such as ASTM D3039M. This work seeks to evaluate the mechanical resistance of a composite of natural Sisal fiber aligned 0° unidirectional in the form of a plate, making a comparison in the tension obtained with experimental data through the universal testing machine EMIC with the theoretical data applying the mixing rule. The methodology used to manufacture these plates was manual, which fits the proposal of using little equipment or technology to obtain these composite materials. On the occasion, glass plates and double-sided tape were used so that the fibers maintained their alignment and it was possible to manufacture them. The results were satisfactory and within expectations for this type of orientation and fiber, obtaining a maximum tension of 147.10 MPa for the experimental test and 147.24 obtained theoretically by the mixture rule equation. Experimental data usually differ from theoretical ones and one of the proposals of this work is to evaluate the possible possibilities of factors that influence this differentiation.