Papers by Keyword: Filament Wound Shell

Abstract: The external curing method is usually adopted as the traditional molding process of thermoset fiber composite shell, which places the wound shell into the thermal compression reactor or the oven to cure. This kind of process greatly limits the molding efficiency because winding and curing proceed respectively and separately. The internal curing can be adopted because of the hollow structure of the cylinder-shaped shell, which heats the mandrel with high pressure steam to realize the in-situ curing of the wound shell. This paper researches the new fiber composite molding process named heated mandrel winding. Not only does the heated mandrel winding inherit the advantages of internal curing process, it also greatly improves molding efficiency and quality. This paper introduces the process principle of heated mandrel winding and uses the finite element analysis software FLUENT to carry out the numerical simulation of steam flow and heat transfer during the mandrel heating process, and the simulation results are verified by experiment. According to the simulation results, the distribution and changing course of the flow field and temperature field of the system are obtained, and the relationships between the physical quantities including pressure, temperature and velocity and the parameters of the steam control and channel structure are analyzed.

Abstract: The fiber reinforced composite materials were widely used for aerospace aircrafts and missile weapons, and the delamination was a major problem which reduced the structural integrity and reliability of the solid rocket motor (SRM) composite shell seriously. In order to locate the delamination damage, the fiber Bragg grating (FBG) strain sensors network was embedded in SRM shell, and a multi-step approach of delamination damage location based on strain energy was performed: the strain field was measured in a scatter grid by the FBG strain sensors network in hydraulic testing; then the continuous displacement and strain field was reconstructed with relative sensors data using a moving least square (MLS) mesh-free fitting method; the strain energy of each subregions was calculated from the reconstructed data; finally the damaged subregions was identified successfully by singularity value of strain energy. The results of simulation and experiment indicated that the damage identification and location only required the measure of strain field of the SRM shell, and the presented approach achieved higher accuracy.