Enhancement of thrust vector control by composite reinforcements in conical elastomeric bearing

Abstract

Conical elastomeric bearings offer high propellant-carrying capacity and superior structural performance over a cylindrical elastomeric bearing in a solid propulsion rocket motor for comparable thrust vector control. In the present study, the performance and weight reduction of conical elastomeric bearings were significantly enhanced by employing composite reinforcements instead of conventional metallic reinforcements. The fabrication challenges, such as dimensional accuracy and defect mitigation of bidirectional curved composite reinforcements and composite conical elastomeric bearings, were addressed systematically using novel techniques for the given conical geometry. A combination of hand layup and match-die moulding process was developed to fabricate the composite reinforcements with bidirectional curvature. While a collapsible and reusable tooling using resin transfer moulding was devised to manufacture the conical and cylindrical elastomeric bearings. The performance of the composite conical elastomeric bearings was validated through qualification tests. A vectoring angle as high as $5^{°}$ was achieved for composite conical elastomeric bearings compared to $3^{°}$ achieved by the cylindrical elastomeric bearing with metallic reinforcements.