Study On Thermal Conductivity Of 3D Braided Composites

In this paper, I use the thermal conductivity instrument to study the thermal conductivity of carbon fiber/epoxy resin three-dimensional braided composite materials and carbon fiber/epoxy resin laminate. The effects of braiding Angle, fiber volume content and temperature on the heat conduction properties of three-dimensional braided composite material were analyzed. The thermal conductivity performances of the three-dimensional Braided Composites (4D), three dimensional and five directional braided composites (5D) and laminated composites were compared. Through the experiment and analysis, the following conclusions were got:In the case of the same fiber volume fraction, the thermal conductivity of three-dimensional four-directional braided composite, three-dimensional five-directional braided composites and laminated composites increased with the increasing of braiding angle/orientation angle; with the same braiding angle/ orientation angle under the circumstances, the thermal conductivity of three-dimensional four-directional braided composite, three-dimensional five-directional braided composites and laminated composites increased with the increasing of fiber volume fraction; when the braiding angle and fiber volume content is same, the thermal conductivity of the three-dimensional five-directional braided composites is smaller than that of the three-dimensional four-directional braided composite. The three-dimensional braided composite and laminated composites with the same fiber volume fraction or the fiber orientation, the heat transfer coefficient of the laminated composites is bigger than that of the three-dimensional braiding composite.Under the same other parameters, testing by changing the direction of the sensor, I verified the heat transfer properties of the three dimensional four-directional braided composites (4D), three dimensional five-directional braided composites (5D) and laminated composites. The heat transfer coefficients meadured by corresponding to braiding angle and measured by changing the direction of the sensor are little difference. In the case of the same fiber volume fraction, thermal conductivity of three-dimensional four-directional braided composite, three-dimensional five-directional braided composites and laminated composites increased with the increasing of braiding angle/orientation angle; at the same braiding angle/ orientation angle under the circumstances, the thermal conductivity of three-dimensional four-directional braided composite, three-dimensional five-directional braided composites and laminated composites increased with the increasing of fiber volume fraction.I measured the heat transfer performance of the three dimensional four-directional braided composites (4D), three dimensional five-directional braided composites (5D) and laminated composites, at room temperature,50 degrees,70 degrees and 90 degrees, respectively. I concluded that, for different orientation Angle and fiber volume content of laminated composites, when the orientation Angle and fiber volume content are identified, the heat conduction coefficient of laminated composite materials is decreased with the increase of temperature. For different braiding Angle and fiber volume content of three dimensional composite materials, when the braiding Angle and fiber volume content are identified, the heat transfer coefficient of braided composites is decreased with the increase of temperature.