Effects of short fiber tip geometry and inhomogeneous interphase on the stress distribution of rubber matrix sealing composites

Abstract

The normal and interfacial shear stress distributions with flat fiber tip of short-fiber-reinforced rubber matrix sealing composites (SFRC) compared with the shear lag model were investigated by using the finite element method (FEM). The results indicate that stress values do not agree with those calculated by the shear lag model. The effect of different geometrical shapes of fiber tip on the stress distributions of SFRC was also investigated. The geometrical shapes of fiber tip under present investigation are flat, semi-elliptical, hemispherical, and circular cone, respectively. The results show that the hemispherical fiber tip transfers the load with less stress concentration and is contributed to controlling the interface debonding failure more effectively than other shapes of fiber tip. Further study on the effect of the inhomogeneous interphase properties on the normal and interfacial shear stresses of hemispherical fiber tip was also conducted. The results indicate that the normal stress increases with the increase of the interphase thickness and interfacial shear stress remains unchanged, and the normal stress values of SFRC with interphase are higher than those without interphase. The interphase elastic modulus has no influence on the stress distributions along the direction to the fiber axis. The stress distributions along the radial direction in the interphase end are largely dependent on the interphase elastic modulus, and the interfacial shear stress is larger than the normal stress, which reveals that a significant part of the external load is transferred from the fiber to the matrix through shear stresses within the interphase.

A new structure-property connection in the skeletal elements of the marine sponge Tethya aurantia that guards against buckling instability

“…Thus, our numerical results do not contradict Eshelby’s solution. In fact, they are consistent with results from computational models of short fiber reinforced composites4546, full-field elasticity solutions for rigid line inclusions47, and photoelasticity experiments on line-like inclusions48. Based on the insight gained from our computational mechanics calculations, we modeled the effect of the spongin by replacing the tractions applied to the ends of the RoC with opposing point forces, ± P M at the Sxa’s ends (see Fig.…”

Effects of thermal histories on interfacial properties of carbon fiber/polyamide 6 composites: Thickness, modulus, adhesion and shear strength

“…However, inconsistencies are still exist. For example, thin interface thickness and high interface Young's modulus resulted in efficient stress transfer at the fiber interface using a simple representative volume element (RVE) approach based on the finite element analysis (FEA) [2], while results simulated by Yu et al [3] indicated that the normal stress increased with the increase of the interface thickness and interfacial shear strength (IFSS) remained unchanged, and the interface modulus had no influence on the stress distributions along the direction to the fiber axis. Kim and Mai [4] also reported that there were inconsistencies on the influence of thickness and modulus on the LTE.…”

Interphase effect on the interfacial debonding behavior in short-fiber-reinforced rubber composites

“…ε 0 is the axial tensile strain at r = r m . The aspect ratio of fiber s can be written as f / slr = (9) When the shear stress at the interface reaches a critical value τ a , the friction sliding will happen. Ordinarily, the frictional resistance is less than τ a .…”

“…A number of micromechanics models have been developed to predict the stress transfer, among which the shear-lag model [6,7] and the finite element analysis [8,9] are the most widely used. Yuan et al [10] presented an interphase layer mode to describe the interphase of composites and analyzed the effects of the interphase thickness and interfacial shear strength on the peak load.…”