CHARACTERIZATION OF A FIBER-REINFORCED PPS COMPOSITE BY DYNAMIC-MECHANICAL ANALYSIS - EFFECT OF ASPECT RATIO AND STATIC STRESS

Dynamic mechanical analysis has been increasingly used to study and characterize the mechanical properties of materials in general and of composites in particular, owing to the frequent dynamic loading situations found where composites are used. Whilst the DMA techniques have been established for homogeneous materials, a more precise approach for anisotropic materials is currently required. This paper analyses the effects of the bending aspect ratio and of applied static and dynamic stresses on the resulting dynamic modulus for a fibre-reinforced PPS composite. Results indicate that for such composites with a high E/G ratio, shear deformation cannot be ignored and a large bending aspect ratio is required before the dynamic modulus approaches a limiting value, but does not reach the value of the Young's modulus in tension. Increasing the applied static stress also increases the resulting measured modulus, with the effect being greater, the higher the E/G ratio.