EFFECT OF SHEAR MODULAR RATIO (GF/GM) AND TRANSVERSE SHEAR MODULUS ON THE TWISTING STRENGTH OF A FIBER- REINFORCED COMPOSITE ROD

Abstract

In this research, the effect of shear modular G23 variation is investigated on the twisting strength of a unidirectional fiber reinforced composite rod subjected to various uniform static twisting moments. An optimization of the best modular ratio is also made to determine the maximum allowable twisting strength. The problem is simulated by the software of ANSYS v12 to determine the stress fields distribution throughout rod domain and the section of highest shear stresses in different planes (critical sections), a graphical representation has been made to the results obtained from a finite element analysis to rod of interest. The elastic properties of the composites investigated are found using the rules of mixtures and Halpin-Tsi equation along with the sftware of Matlab v6.5. Various types of fibers and matrices are used to change the shear modulus of G23 . It is found that most dominant effect is that of matrices whose the increase of its shear modulus (Gm ) is getting inversely proportional to angle of twist (θ) according to a certain polynomial function of a second degree and there is a minor effect of fibers on it. The results of the analysis made by the package of ANSYS v12 were compared with the analytical solution showing the same behavior and reasonably convergent values.