Dynamic and Static Torsional Characterization of Pultruded Hybrid Cylindrical Composite Rods

Abstract

The objective of this paper is to demonstrate the effects of hybridization on the static and dynamic behavior of pultruded composite rods subjected to a torsional mode of deformation. Candidate materials that were tested included cylindrical composites made from unidirectional glass and graphite fibers, and hybrids of glass-graphite/epoxy in various shell-core type configurations, fabricated by the pultrusion manufacturing process. The dynamic torsional stiffness and damping were evaluated by the FFT based impulse-frequency response vibration technique. The static shear modulus was obtained using a conventional low torque tester and the initial tangent modulus method. This study has shown that for a given fiber volume fraction glass/epoxy exhibits higher shear modulus than graphite/epoxy; and hybridization of these two material systems results in better dynamic performance by placing glass fibers in the outer shell region.

Energy Absorption of Pultruded Hybrid GlassGraphite Epoxy Composites under High Strain-Rate SHPB Compression Loading

“…Fiber-reinforced pultruded composites are being used frequently in many advanced applications due to their many advantages such as structural strength, improved mechanical properties, low weight, and durability [1] [2]. These properties, along with their low-cost, enabled pultruded composites to replace traditional materials such as steel, wood, aluminum, and other composites in structural applications [3].…”

“…Graphite fibers, on the other hand, have a very high tensile modulus as well as high strength and low weight. Disadvantages of graphite fibers include low impact resistance and higher cost [1] [2]. Several investigations have been performed on pultruded glass and graphite/epoxy "hybrids" in the Composite Materials Research Laboratory at the University of Mississippi [2]- [9].…”

“…Disadvantages of graphite fibers include low impact resistance and higher cost [1] [2]. Several investigations have been performed on pultruded glass and graphite/epoxy "hybrids" in the Composite Materials Research Laboratory at the University of Mississippi [2]- [9]. By the "hybridization" of both glass and graphite fibers in various proportions within the same epoxy matrix, structures can be designed to achieve optimal balance of the two materials' properties.…”

“…By the "hybridization" of both glass and graphite fibers in various proportions within the same epoxy matrix, structures can be designed to achieve optimal balance of the two materials' properties. For example, Kumar and Mantena [2] investigated the characteristics of pultruded cylindrical rods under static and dynamic torsional modes of deformation. While pure glass/epoxy exhibited higher shear modulus than pure graphite/epoxy, the hybridization of these two materials with specific amount of glass fibers in the outer shell region resulted in better dynamic performance.…”

Dynamic Response of Pultruded Glass-Graphite/Epoxy Hybrid Composites Subjected to Transverse High Strain-Rate Compression Loading

“…On the other hand, graphite fibers possess very high tensile modulus, low weight and low impact resistance. A number of investigations have been carried out on pultruded composites [1]- [13]. Their results illustrate that hybridization with different percentages of glass and graphite within the same epoxy matrix has a significant effect on the mechanical properties.…”