Depreciation of natural resources leads to an increasing demand for sustainable materials. Fiber-reinforced plastics are known for combining low specific weight with high stiffness and toughness, making them the preferred material for the design of lightweight structures. However, one of the main problems with the use of this material is the limited recyclability of the material due to the necessity to split up the fiber and matrix composite into its constituents. Furthermore, the use recycled fibers require the use a recyclable sizing or alternatively, the cleaning, and re-application of new sizing to the fibers. The goal of this paper is to introduce a method to improve the mechanical properties of glass fiber reinforced thermoplastic polymers through a re-usable chemical modification of the fiber-matrix interface by using adhesion promoting coatings. The surface reactions in this approach are suitable for a wide spectrum of matrix systems. In a second part of the present paper, a characterization method for determination of the interface properties is suggested. For this purpose, micro tensile specimens are prepared and tested. The experiments are evaluated numerically using a finite element simulation based on 1:1 models of the specimens in conjunction with reverse engineering.
Objective of the present study is the definition of a continuum damage mechanics material model describing the degradation of fiber reinforced materials under fatigue loads up to final failure. Based on the linear elastic framework, a brittle damage model for fatigue conditions is derived, where the damage constitutes the only nonlinearity. The model accounts for damage effects by successive degradation of the elastic moduli. Assuming that material damage is driven by microplastic work, a stress-driven damage evolution equation is defined. For generality, a fully three-dimensional formulation on single ply level is employed. The model is implemented into a finite element program. In a validation against experimental data on filament-wound carbon fiber reinforced material, the model proves to provide a good numerical approximation of the damage during the cyclic loading history up to final material failure.
A major issue concerning Carbon Fibre Reinforced Polymer (CFRP) materials under cyclic loading is that the materials often undergo material degradation starting from the initial stage of the loading. For a laminate that consists of different fibre orientation plies, this becomes crucial as it causes redistribution of stresses and strains during the lifetime of the component. Understanding the importance of a reliable fatigue damage and degradation model in the development of reliability assessment of CFRP materials, the present studies contribute to this by considering the effect on a single-ply material level, exclusively under fatigue loading. The model is restricted to be applied to stiff and brittle materials with characteristic properties similar to those of carbon-epoxy composites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.