Simple torsion test for shear moduli determination of orthotropic compositesThe shear moduli G13 and G23 for two different composites (AS/3501 and T300/5209) of uniaxial and cross-ply fiber orientations were determined by torsion testing of flat specimens of rectangular cross section. Torsion tests were run under controlled angle of twist in an electro-hydraulic servo-controlled test system. Both laser and potentiometer methods of measuring the angle of twist were used. The in-plane shear modulus was calculated with a formula for transversally isotropic materials and a formula for orthotropic materials, while the out-of-plane shear modulus was calculated from the orthotropic material formula. Neither the uniaxial nor the angle-ply composite materials studied were transversely isotropic. The degree of anisotropy for the angle-ply materials was several times greater than that of the uniaxial composites. For specimens of uniaxial fiber orientation, the in-plane shear moduli could be calculated to a good approximation by using the isotropic formula and test machine deflection data.
Document ID
19790033024
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Sumsion, H. T. (NASA Ames Research Center Moffett Field, CA, United States)
Rajapakse, Y. D. S. (NASA Ames Research Center Moffett Field, Calif., United States)
Date Acquired
August 9, 2013
Publication Date
January 1, 1978
Subject Category
Composite Materials
Meeting Information
Meeting: ICCM/2; Second International Conference on Composite Materials