Large deflection analysis of pneumatic envelopes using a penalty parameter modified material model

• Published in: Finite elements in analysis and design Vol. 37; no. 3; pp. 233 - 251
• Main Authors: Liu, Xinxiang, Jenkins, Christopher H., Schur, Willi W.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2001; Elsevier
• Subjects: Computational techniques; Exact sciences and technology; Finite-element and galerkin methods; Fundamental areas of phenomenology (including applications); Mathematical methods in physics; Other structures; Physics; Solid mechanics; Structural and continuum mechanics; Structural mechanics (beam, string...); Theory and numerical methods; Constitutive equation; Compression; High strain; Indeterminate structure; Deflection; Strain energy; Displacement(deformation); Encoding; Numerical method; Transverse load; Finite element method; Degenerate state; Parachutes; Linear codes; Modelling; Non linear effect; Balloons; Modified material
• ISSN: 0168-874X; 1872-6925
• DOI: 10.1016/S0168-874X(00)00040-8

The computational challenge associated with pneumatic envelopes, such as balloons and parachutes, is due to the complication of their underconstrained and no-compression nature. Underconstrained behavior leads to large displacements without concomitant strain energy; no-compression behavior leads to a degenerate, wrinkled state. In this paper, we discuss issues surrounding modeling such structures. We provide a method to analyze pneumatic envelopes through a penalty parameter-modified constitutive relation embedded in a non-linear finite element code. Such an approach is also adaptable to the user-provided material function port available with many commercial finite element codes. Validation examples given are the inflated cantilever cylinder subjected to transverse tip load, inflated cantilever cylinder subjected to twist moment, and the inflation of a round parachute.