Fiber Composite Article Review

.....mechanical feasibility of a hybrid Epoxy/Glass/Flax composite material for handling bone fracture fixation like fracture plates. The introduction begins with definition of 'advanced engineering composite material'. The term means combination of both strong and soft constituents that are mixed together to enable the production process leading to enhancement of properties of the matrix as well as helping in the transference of the load between strong and soft materials due to their major thermal, mechanical, physical and corrosion resistance. These materials see use in engineering applications like biomechanical, aerospace, and automotive.

The study continues with the introduction noting some drawbacks to synthetic fibers, with key mention of glass and carbon. Such drawbacks include high energy consumption, non-renewability, and non-recyclability. In fact, interest has grown and shifted to use of natural fibers. Natural fibers provide manufacturers with several advantages such as ease in recycling, sustainability, easier to manufacture (requires less energy), and they are lighter and subsequently cheaper. Composite materials have seen consideration for use in fracture fixation mechanism like IM nails and other biomedical applications. The authors continue with section 2: material and experimental methods highlighting the manufacturing of Epoxy/Flax/Glass specimens.

These composite plates have angle ply and unidirectional staking sequences. They are made using twelve layers of flax fibers as the core and four layers of glass fiber. The general study design included testing such as tension, Rockwell hardness tests, compression, and three point bending. The tests were performed to identify mechanical properties of the Epoxy/Glass/Fiber composite specimens. The authors examined flexural modulus, longitudinal strength, flexural strength, and Young's modulus and hardness.

The objective included determining the moisture rate absorption to see how long sch materials will degrade due to exposure over long time periods. This needs to the next section, moisture absorption tests and then followed by the next section, tension tests. The authors used ASTM standards for the tensile test experiments. They measured ultimate strain as well as ultimate strength and then calculated standard deviation along with mean value. The compression tests facilitated obtainment of the modulus of elasticity via application of linear regression to what the authors noted as linear domain of experimental stress-strain curve.

The bending tests saw experimentation on 5 specimens using the three-point bending with the final section detailing Rockwell hardness tests. The results sections showed varied results beginning with the moisture absorption test which saw a steady state after forty days. The tension test saw results involving brittle fracture that demonstrated linear behavior until failure. The compression test revealed delimitation of all five specimens at adjacent surface of both the flax and glass plies. The bending test results proved to show fiber breakage and matric cracking followed by buckling of flax plies. Section 3.6 discussed comparison to previous studies suggesting scattered results exist within the literature concerning composite reinforced mechanical properties. General findings as well as practical implications revealed that this study was the first to explore Glass/Epoxy/Flax mechanical properties for the use of orthopedic application like bone plating.

Of the limitations discussed one noted the curvature of the plate playing a significant part in the stabilization of bone fragments within the fracture site. The authors used nothing but straight specimens that could have affected general stiffness including ultimate strength. For instance, curvature may minimize compressive load-to-failure. Considerations for future work concerns biocompatibility that includes osteogenesis and cytotoxicity tests using the same flax fiber/epoxy hybrid. The authors states future studies must be made to assess fatigue behavior of Flax/Glass/Epoxy composite under certain conditions that include biocompatibity of existing composite material.

Works Cited

Manteghi, Saeed et al. "Investigation Of The Mechanical Properties And Failure Modes Of Hybrid Natural Fiber Composites For Potential Bone Fracture Fixation Plates." Journal of the Mechanical Behavior of Biomedical Materials 65 (2016): 306-316. Web.