Adhesion efficiency between phases in fibre-reinforced polymers by means of the concept of boundary interphase

The Thermal Conductivities of Periodic Fibrous Composites as Defined by a Mathematical Model

“…The fiber content was determined, as customary, by igniting samples of the composite and weighting the residue, which gave the weight fraction of glass as: 0.28%. 79.6 w f ± = This and the measured values of the relative densities of permaglass (pf = 2.55 gr/cm 3 ) and of the epoxy matrix (p = 1.20 gr/cm 3 ) gave the value Uf = 0.65. Furthermore, chip specimens with a 0.004 m diameter and thicknesses varying between 0.001 and 0.0015 m made either of the fiber composite of different filler contents, or of the matrix material, were tested by the authors on a differential scanning calorimetry (DSC) Thermal Analyzer at the zone of the glass transition temperature for each mixture, in order to determine the specific heat capacity values.…”

“…In a model developed by Theocaris et al [1,2] this intermediate phase has been considered initially as being a homogeneous and isotropic material. In a better approximation [3] a more complex model has been introduced, according to which the fiber was surrounded by a series of successive cylinders, each one of them having a different elastic modulus in a step-function variation with the polar radius. Moreover, mathematical analyses of inhomogeneous interphases started, probably, with the work of Kanaun and Kudryavtseva [4] on the effective elasticity of a medium with spherical inclusions surrounded by radially inhomogeneous interphase zones.…”

An Upper Bound of Longitudinal Elastic Modulus for Unidirectional Fibrous Composites as Obtained from Strength of Materials Approach

“…In a simplified approach which was adopted in previous papers [7,8], this natural intermediate phase was assumed to be a homogeneous and isotropic material, whereas in another groups of studies [9][10][11] more advanced and prominent models were introduced, the main feature of which was the fibre to be occupied by a series of successive coaxial cylinders, each of which has a different stiffness in a step-function variation in terms of polar radius. Further, a valuable experimental study towards the estimation of mechanical and thermal properties of unidirectional fibrous composite materials was carried out by Clements and Moore [12] whereas a theoretical and experimental investigation of mechanical properties of polymeric particulate and unidirectional fibrous composites by the interphase concept was performed in a previous paper [13].…”

The Thermal Conductivities of Periodic Fibrous Composites as Defined by a Mathematical Model

“…In [5,6] the previously mentioned third phase (interphase) was assumed as a homogeneous and isotropic, whereas in [7], an improved model was suggested, according to which the fiber was surrounded by a series of successive cylinders, each of which has a different elastic modulus in a step-function variation with the polar radius.…”