Abstract: A manufacture method of a three dimensional (3D) braided composite tube with a throat section includes: providing an assembled mandrel comprising an upper mandrel and a lower mandrel, and braiding an 3D braided inner layer on the upper mandrel; winding fiber yarns to form a fiber yarn layer over the 3D braided inner layer; tightening the 3D braided inner layer to the assembled mandrel by an appropriate tension force when winding; and infiltrating resin and increasing temperature to cure the resin for obtaining a composite tube with a narrower throat section. The present invention takes advantage of winding fiber yarn outer layer to keep the radius of the throat of the 3D braided inner layer to meet design requirement. Additionally, the hoop strength of the throat section is increased so that the metal shell can be made thinner to reduce the weight of the rocket nozzle.

Abstract: A manufacture method of a three dimensional (3D) braided composite tube with a throat section includes: providing an assembled mandrel comprising an upper mandrel and a lower mandrel, and braiding an 3D braided inner layer on the upper mandrel; winding fiber yarns to form a fiber yarn layer over the 3D braided inner layer; tightening the 3D braided inner layer to the assembled mandrel by an appropriate tension force when winding; and infiltrating resin and increasing temperature to cure the resin for obtaining a composite tube with a narrower throat section. The present invention takes advantage of winding fiber yarn outer layer to keep the radius of the throat of the 3D braided inner layer to meet design requirement. Additionally, the hoop strength of the throat section is increased so that the metal shell can be made thinner to reduce the weight of the rocket nozzle.