Flexural Rigidity (D) in Beams

Abstract

This thesis presents the theory behind the symmetrical and unsymmetrical beams with different cross-sections, the mathematical procedure in calculating the flexural rigidity of symmetrical beams and summarizing the experimental verification by mathematical data processing of the flexural rigidity by three-point bending.

The core of the method section is to test theoretically by using the composite compressive strength modeler (CCSM) software and experimentally in the laboratory by using the material bending machine a solid fiberglass and a sandwich beam. The results obtained for the solid fiberglass was found to be theoretically 32 Nmm2 and experimentally 31.1 Nmm2. For the sandwich beam along the direction of the orientation of the fiber theoretically 155 Nmm2 and experimentally 153.3 Nmm2. As for the sandwich beam with the same properties but with a direction perpendicular to the fiber theoretically 45.1 MNmm2 and experimentally 47.22 Nmm2. The comparison of flexural rigidity values was found to be 3.1% for the solid fiberglass, 1.1% for the sandwich beam along the direction of the orientation of the fiber and -4.6% with a direction perpendicular to the fiber. Moreover, for the four-section module, the values obtained for the moments of the outer layer contributed seven times more to rigidity than the inner layer and for the six-section module the second outermost layer contributed seven times more than the innermost layer and the outermost layer nineteen times more to rigidity than the innermost layer.