A new dawn in the use of advanced composite materials
There exists in Industry a market for low cost, lightweight, stiff, high strength engineering struts. Performance struts are used within satellites, aircraft, bridges, buildings and vehicles. They have many different applications, such as structural supports, actuators, robotic arms and manipulators, and as load transferring links in high speed machinery.
The need to reduce the mass of structures has in recent years, led to considerable interest in the use of advanced composite materials (i.e. FRP’s, MMC’s and Ceramics) which possess a greater specific strength and stiffness than metals, and thus offer performance gains over traditional struts in compression. However, members made from such special materials can present problems in the method of their attachment to the rest of the overall structure.
The innovative HPC-Strut product meets this challenge by exploiting an elegant and simple design assembly concept, giving it distinct pricing and technical advantages over both conventional all-metallic, and advanced all composite struts.
In order to improve on current lightweight strut technology, the HPC-Strut product offers increased buckling resistance by utilising the benefits of both metals and advanced composite materials but without connection and thermal mismatch problems. The HPC-Strut design is unique and is based on sound mechanical engineering principles and established materials and manufacturing techniques.
The main feature of the HPC-Strut product is the way joint difficulties are overcome by utilising the most useful properties of the materials comprising the strut assembly: the high strength and stiffness to weight ratio of the advanced material, together with the ductility of metals. The degree of innovation lies in the unique way the advanced material is incorporated into, and worked by the strut assembly, without having to rely on either mechanical fastening or adhesive bonding, thus eliminating the major problem usually associated with the implementation of materials of this kind.
The tensile performance of the sleeved strut assembly is streamlined by the fact that only the inner metallic tube is directly supporting axial loads. The tensile strength of the strut is thus calculated ignoring the outer composite sleeve, whereas during compressive loading the presence of the outer composite sleeve is of significance: the composite contributes to resisting any tendency of the assembly to flex, thereby increasing the maximum compressive buckling load that the strut can sustain.
No composite-metal fasteners or adhesive joints
Elimination of assembly thermal mismatch
Bespoke tension/compression capacities
Simple assembly /
Repairable and upgradeable
The HPC-Strut offers significant performance gains over struts composed of traditional materials (with respect to specific strength and stiffness ie weight), and over struts composed entirely of advanced materials (with respect to cost, simplicity, replaceability, and integrity of connections).
The HPC-Strut is novel on an international basis and has the potential to be exploited across a wide range of application industries including low cost spacecraft vehicle applications within the Access to Space market, civil and military aerospace, robotic arm and manipulator fields, high speed machinery and progressive civil engineering structures.