A Study of the Fiber-Matrix Interface in Composite Materials

1992 ◽  
Vol 59 (2S) ◽  
pp. S163-S165 ◽  
Author(s):  
Jin O. Kim ◽  
Haim H. Bau

A novel experimental technique for studying the characteristics of the interface between the fibers and the matrix in both undamaged and damaged fiber-reinforced composite materials is described. The experimental technique involves the transmission of stress waves in one or more fibers of the composite. The characteristics of the stress waves, such as speed, dispersion, and attenuation, are measured. These measured variables can be correlated with the characteristics of the bonding between the fiber and the matrix.

2019 ◽  
Vol 1 (1) ◽  
pp. 276-280
Author(s):  
Lenka Markovičová ◽  
Viera Zatkalíková ◽  
Patrícia Hanusová

Abstract Carbon fiber reinforced composite materials offer greater rigidity and strength than any other composites, but are much more expensive than e.g. glass fiber reinforced composite materials. Continuous fibers in polyester give the best properties. The fibers carry mechanical loads, the matrix transfers the loads to the fibers, is ductile and tough, protect the fibers from handling and environmental damage. The working temperature and the processing conditions of the composite depend on the matrix material. Polyesters are the most commonly used matrices because they offer good properties at relatively low cost. The strength of the composite increases along with the fiber-matrix ratio and the fiber orientation parallel to the load direction. The longer the fibers, the more effective the load transfer is. Increasing the thickness of the laminate leads to a reduction in the strength of the composite and the modulus of strength, since the likelihood of the presence of defects increases. The aim of this research is to analyze the change in the mechanical properties of the polymer composite. The polymer composite consists of carbon fibers and epoxy resin. The change in compressive strength in the longitudinal and transverse directions of the fiber orientation was evaluated. At the same time, the influence of the wet environment on the change of mechanical properties of the composite was evaluated.


Author(s):  
H. G. Kim ◽  
Ian R. Grosse ◽  
S. V. Nair

Abstract Knowledge of internal stress fields in fiber or whisker reinforced composites is crucial to the design, manufacturing and applications of composites. Finite element analysis (FEA) presents the only rigorous approach to a solution of this problem. However, the application of FEA to composites requires careful attention to the geometry of the optimum mesh used in the analysis. Standard energy analysis and mesh refinement procedures have yet to be generalized or extended to the special case of fiber or whisker reinforced non-homogeneous composites. Current automatic mesh generation codes do not provide the optimum mesh for composites. This paper is concerned with the development of a generalized approach for optimal mesh refinement in a short fiber reinforced composite. Optimization procedures are based on the calculation of the error in energy norm for global convergence and the traction differential approach at the fiber/matrix interface for local convergence whereas the mesh refinement strategy is based on the use of elongated elements at the fiber/matrix interface. An isoparametric finite element model that has a periodic hexagonal array of elastic fibers surrounded by an elastic matrix was used in the investigation. It is shown that this approach provides the optimum mesh with a much more rapid convergence than conventional meshes. In this manner converged local solutions can be obtained with significantly lower degrees of freedom than by conventional mesh refinement methods.


Author(s):  
Chad Braver ◽  
Matthew Tumey ◽  
Adam Harlow ◽  
Qingyou Han

The mechanical properties of fiber-reinforced composite materials are highly dependent on proper saturation of the resin within the reinforcement fibers. The research evaluates the effect of ultrasonic treatment during composite curing, in an effort to increase interlaminar bonding strength, lower void content, and improve the matrices ability to transfer stresses to the reinforcement fiber. The testing methods that were performed evaluated the effects or the ultrasonic treatment on the specimen in three point bending, and shear between layers of the matrix. The mechanical properties and the microstructure of the test specimen are discussed.


2018 ◽  
Author(s):  
Karla Rosa Reyes ◽  
Karla Rosa Reyes ◽  
Adriana Pavia Sanders ◽  
Lee Taylor Massey ◽  
Corinne Hagan ◽  
...  

2021 ◽  
pp. 096739112110141
Author(s):  
Ferhat Ceritbinmez ◽  
Ahmet Yapici ◽  
Erdoğan Kanca

In this study, the effect of adding nanosize additive to glass fiber reinforced composite plates on mechanical properties and surface milling was investigated. In the light of the investigations, with the addition of MWCNTs additive in the composite production, the strength of the material has been changed and the more durable composite materials have been obtained. Slots were opened with different cutting speed and feed rate parameters to the composite layers. Surface roughness of the composite layers and slot size were examined and also abrasions of cutting tools used in cutting process were determined. It was observed that the addition of nanoparticles to the laminated glass fiber composite materials played an effective role in the strength of the material and caused cutting tool wear.


Author(s):  
Mohamed Gaith ◽  
Cevdet Akgoz

A new procedure based on constructing orthonormal tensor basis using the form-invariant expressions which can easily be extended to any tensor of rank n. A new decomposition, which is not in literature, of the stress tensor is presented. An innovational general form and more explicit physical property of the symmetric fourth rank elastic tensors is presented. The new method allows to measure the stiffness and piezoelectricity in the elastic fiber reinforced composite and piezoelectric ceramic materials, respecively, using a proposed norm concept on the crystal scale. This method will allow to investigate the effects of fiber orientaion, number of plies, material properties of matrix and fibers, and degree of anisotropy on the stiffness of the structure. The results are compared with those available in the literature for semiconductor compounds, piezoelectric ceramics and fiber reinforced composite materials.


Sign in / Sign up

Export Citation Format

Share Document