Evaluating a Test Parameter in Static Bending for Pinus sp. Wood

Abstract. The study aimed to analyze the longitudinal modulus of elasticity (E_m), based on static bending tests, in different spans and confirm that it’s necessary adopt as 21 the ratio between span and height of the cross section of the specimen to turn no significant the influence of shear stress on vertical deflection. So, simplified equation to determine E_m can be employed. Specimens of Pinus elliottii var. elliottii and Pinus elliottii var. elliottii × Pinus cariabeae hondurensis (hybrid), came from Itapeva region, São Paulo State, Brazil, were considered. Bending tests were conducted in Labs of Experimental Campus Itapeva, UNESP, adapting recommendations of Brazilian Code ABNT NBR 7190. Twelve specimens of each species were tested. The trend lines for the plotted graphics showed clearly a nonlinear behavior until the neighborhood of ratio 21 and no expressive variations after this point, confirming that normative recommendations are correct.