Viscoelastic behaviour of pumpkin balloons

T. Gerngross, Yixiang Xu, S. Pellegrino

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The lobes of the NASA ULDB pumpkin-shaped super-pressure balloons are made of a thin polymeric film that shows considerable time-dependent behaviour. A nonlinear viscoelastic model based on experimental measurements has been recently established for this film. This paper presents a simulation of the viscoelastic behaviour of ULDB balloons with the finite element software ABAQUS. First, the standard viscoelastic modelling capabilities available in ABAQUS are examined, but are found of limited accuracy even for the case of simple uniaxial creep tests on ULDB films. Then, a nonlinear viscoelastic constitutive model is implemented by means of a userdefined subroutine. This approach is verified by means of biaxial creep experiments on pressurized cylinders and is found to be accurate provided that the film anisotropy is also included in the model. A preliminary set of predictions for a single lobe of a ULDB is presented at the end of the paper. It indicates that time-dependent effects in a balloon structure can lead to significant stress redistribution and large increases in the transverse strains in the lobes.
Original languageEnglish
Pages (from-to)1683-1690
Number of pages8
JournalAdvances in Space Research
Volume42
Issue number10
DOIs
Publication statusPublished - 17 Nov 2008

Keywords

  • atmospheric balloons
  • viscoelasticity
  • creep
  • polyethylene film
  • schapery

Fingerprint Dive into the research topics of 'Viscoelastic behaviour of pumpkin balloons'. Together they form a unique fingerprint.

Cite this