4 – Mechanical Test Methods for Lamina

This chapter identifies some of the experimental techniques applicable to composite materials. The possible errors associated with strain gage analysis are presented along with a discussion of the effects of strain gage misalignment. Strain gage reinforcing effects for both axial loading and flexure are discussed. A selected number of test fixtures for estimating mechanical properties in tension, compression, and shear are discussed. The various techniques for establishing the shear modulus ( G 12 ) are presented, and a relative comparison of the methods is discussed. Flexure testing for estimating E x is also discussed. Methods for determining physical properties of lamina (density and coefficients of thermal and hygral expansion) are presented. A brief discussion of fiber testing is also given. The mechanical properties of selected materials are presented in tables.