Development of a Finite Element Analysis (FEA) Framework for Predicting Performance of an EVA Space Suit Lower Arm Assembly

Abstract

The development of new spacesuits is in the critical path for the exploration of the Moon and Mars. Only two suits have been developed since the 1960’s, and neither have benefited from dynamic digital modeling of the design prior to manufacturing. This research develops a Finite Element Analysis (FEA) Framework for modeling the current Extravehicular Activity (EVA) spacesuit in order to measure the effects of several design variables on the predicted performance of crewmembers with varying anthropometric dimensions. It is specifically applied to an EVA pressurized arm and measures performance metrics such as the torque required at the elbow to deform the arm. In the past, fit evaluation has been determined by iterative qualitative assessments by the crewmember after the suit has been manufactured. This often results in poorly fitting suits which restrict mobility, increase energy expenditure, and compromise safety. The developed FEA model allows several variables to be assessed including material properties, delta pressure, details of the elbow joint design, and location of the joint. Results of the model are compared to existing analytical solutions and to the published literature for the current ISS spacesuit. Additionally, an experimental device is designed and constructed, and preliminary test data is compared to FEA-generated results. This FEA “Virtual Twin” model will be an important first step in the development of a “Digital Thread” for future space suit design and development.