Polymer 33.1: 100-105
Fawaz, S. A., Anthony N. Palazotto, and Chyi-Shan Wang (1992)
Axial tensile moduli, compressive moduli and compressive strengths of rigid-rod poly(p-phenylene benzobisoxazole) and stiff-chain poly(p-phenylene terephthalamide), Kevlar™, fibres were measured with a Tecam Micro-tensile Testing Machine. This machine was configured to allow for testing of single fibres in direct tension and compression at extremely small gauge lengths. The appropriate gauge lengths were estimated based on the discussion of Euler buckling and non-uniform stress distribution in anisotropic materials. The measured tensile and compressive moduli were analysed for corrections to machine compliance and possible gauge length error. The corrected compressive moduli were slightly lower than the corrected tensile moduli, probably due to fibre misalignment under compression and the fibrillar nature of the fibres. The fibre axial compressive strengths measured by direct compression were comparable to those measured from recoil and composite tests but lower than those from cantilever beam and elastica loop tests.