Dr Jason Shore


Postgraduate Research Student

Academic and research departments

Surrey Space Centre.

About

My research project

Publications

J. Shore, A. Viquerat, G. Aglietti, G. Richardson (2020)Rotational Stiness of Drum Deployed Thin-Walled Tubular Booms, In: Thin-Walled Structures150106704 Elsevier BV

Tape springs are a type of thin-walled deployable boom that are used extensively in the space industry to deploy sensors, drag sails and antennas. When a tape spring is stowed it coils into a cylindrical shape and so deployment drums are manufactured as cylinders to match. The consequence of this is that when the tape spring is deployed a portion of the cross section remains flat against the cylindrical drum. This has the effect of reducing the stiffness of the tape spring. In this paper a Finite Element (FE) model is presented to capture this reduction. An experimental method for validating the FE model is also presented on which Beryullium-Copper (BeCu) and glass fibre polypropylene (PP) composite tape springs were tested. The FE model is able to predict the rotational stiffness of the BeCu tape springs more accurately than the composite tape springs. The disagreement in the case of the composite tape springs is attributed to inaccuracies in the available data for the mechanical properties, and the assumption that the tape spring does not compress through the thickness. Increasing the drum length has been shown to decrease the rotational stiffness due to increased flattening at the root. BeCu tape springs show an increase of 82\% in the rotational stiffness when the flattened drum region reduces from 90\% to 30\% of the tape springs' width. Glass fibre PP tape springs with a layup of [$\pm$34/0/$\pm$34] show an increase of 65\% when the drum length percentage reduces from 82\% to 27\%. A parametric study showed that the rotational stiffness can be significantly improved with the introduction of local root reinforcing plies.

Jason Shore, Andrew Viquerat, Guy Richardson, Guglielmo Aglietti (2021)The natural frequency of drum-deployed thin-walled open tubular booms, In: Thin-Walled Structures Elsevier

Thin-walled tape springs are extended from cylindrical deployment drums to support instruments and sensors in a cantilevered manner on spacecraft. Attaching tape springs onto the deployment drums results in a partially flattened and partially restrained cross section, which is far from the ideal case of a fixed-free beam. The consequence is a more compliant root condition that has the potential to couple and amplify on-board microvibrations with the natural frequency of the extended instrumentation. In this paper it is shown that an Euler-Bernoulli beam model can be used to calculate the natural frequency of drum-deployed tape springs using elastic boundary conditions to represent the root condition. A Finite Element (FE) model and experimental data are used to validate the beam model's correctly predicted relationships between the natural frequency and tape spring length, f 1,Res. ∝ L −1.5 , and its rotational stiffness, f 1,Res. ∝ k 0.5 rot. For the investigated beryllium copper tape springs the FE model and beam model are in excellent agreement with experiment, with the error < 10%. For carbon fibre epoxy tape springs there is also strong agreement between the FE model and experiment, and approximately 10-20% error with the beam model. On a scale from a hinged beam to a fixed-free beam, the non-* dimensionalised beam equation reveals that the drum-deployed tape springs are close to the hinged beam end of the scale. Two stiffening methods are proposed to increase the stiffness of the tape springs, and hence move the tape springs towards being a fixed-free beam.