Computational Engineering Models for the Design of Mechanical Counterpressure Spacesuits

Superficially, mechanical counterpressure (MCP) spacesuits appear much simpler in design and operation than a gas-filled spacesuit (e.g. the use of taut fabric wrapped around the body removes the challenges of retaining a seal through bearings and reduces that of defending the suit against puncture). However, the unique strains on the surface of an individual�s skin during joint flexure, changes in the local radius of the body, and formation of concavities (where no pressure can be applied) cause MCP suits to be extremely strenuous to design. This paper describes work performed to employ computation engineering principles to the design of MCP suits. Models to compensate for the deformation of the body under MCP were developed. The use of the slip-layer (a comfort layer to be worn beneath the MCP layer) to improve pressure-uniformity was investigated. This considered the use of tuned friction between the layers to allow a controlled reduction in tension and so to apply less pressure around smaller radii without the inclusion of additional tensioning elements. Detailed models for the behaviour of suit elements were developed and a methodology was outlined for the automation of design processes. Overall, this work demonstrates a new methodology for investigating MCP suit concepts that enables research to focus on the design of individual elements, allowing overall suit design to be automated.