Compressive strength of a rigid-rod polymer fiber embedded in an isotropic matrix
- Max-Planck-Institut fuer Polymerforschung, Mainz (Germany)
Rigid-rod polymer fibers like PPTA impress through their high tensile strength, whereas their compressive strength is comparatively disappointing. Thus, there is a long standing interest in understanding and improving the compressive strength of such materials. Theoretical approaches thus far are mostly based on assuming that the onset of compressive failure can be described in terms of elastic buckling. Here we present the results of an approximate elastic stability analysis for a uniaxially anisotropic fiber embedded in an isotropic elastic matrix. This case, which thus far has not been treated properly, corresponds most closely to the experiments which yield the best quantitative measurements. In the limit of a weak matrix, i.e. the matrix shear modulus is small compared to the fiber shear modulus, we obtain a simple formula for the fiber`s compressive strength in terms of its longitudinal Young`s modulus and the matrix`s Poisson`s ratio and shear modulus. In the limit of a strong matrix, the fiber`s compressive strength is solely determined by its shear modulus. The intermediate regime can be accurately described by a simple interpolating expression.
- OSTI ID:
- 127049
- Report Number(s):
- CONF-950402--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ceramic coated rigid rod polymer fibers
Low-temperature compressive strength of glass-fiber-reinforced polymer composites