TY - GEN
T1 - Imperfection-insensitive axially loaded cylindrical shells
AU - Ning, Xin
AU - Pellegrino, Sergio
N1 - Funding Information:
We thank Dr. Martin Mikulas (National Institute of Aerospace) and Professor Ekkehard Ramm (University of Stuttgart) for helpful comments and advice, and Professor Petros Koumoutsakos (ETH Zurich) for recommending the CMA-ES algorithm to us. We also thank John Steeves (Caltech) for providing the properties of the composite material used in the present study, Keith Patterson and Ignacio Maqueda (Caltech) for help and advice regarding the fabrication and testing of wavy shells. Financial support from the Resnick Institute at California Institute of Technology is gratefully acknowledged.
PY - 2013
Y1 - 2013
N2 - The high efficiency of monocoque cylindrical shells in carrying axial loads is curtailed by their extreme sensitivity to imperfections. For practical applications, this issue has been alleviated by introducing closely stiffened shells which, however, require expensive manufacturing. Here we present an alternative approach that provides a fundamentally different solution. We design symmetry-breaking wavy cylindrical shells that avoid imperfection sensitivity. Their cross-section is formulated by NURBS interpolation on control points whose positions are optimized by evolutionary algorithms. We have applied our approach to both isotropic and orthotropic shells and have also constructed optimized composite wavy shells and measured their imperfections and experimental buckling loads. Through these experiments we have confirmed that optimally designed wavy shells are imperfection-insensitive. We have studied the mass efficiency of these new shells and found them to be more efficient than even a perfect circular cylindrical shell and most stiffened cylindrical shells.
AB - The high efficiency of monocoque cylindrical shells in carrying axial loads is curtailed by their extreme sensitivity to imperfections. For practical applications, this issue has been alleviated by introducing closely stiffened shells which, however, require expensive manufacturing. Here we present an alternative approach that provides a fundamentally different solution. We design symmetry-breaking wavy cylindrical shells that avoid imperfection sensitivity. Their cross-section is formulated by NURBS interpolation on control points whose positions are optimized by evolutionary algorithms. We have applied our approach to both isotropic and orthotropic shells and have also constructed optimized composite wavy shells and measured their imperfections and experimental buckling loads. Through these experiments we have confirmed that optimally designed wavy shells are imperfection-insensitive. We have studied the mass efficiency of these new shells and found them to be more efficient than even a perfect circular cylindrical shell and most stiffened cylindrical shells.
UR - http://www.scopus.com/inward/record.url?scp=84880804711&partnerID=8YFLogxK
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U2 - 10.2514/6.2013-1768
DO - 10.2514/6.2013-1768
M3 - Conference contribution
AN - SCOPUS:84880804711
SN - 9781624102233
T3 - 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference
BT - 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
T2 - 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
Y2 - 8 April 2013 through 11 April 2013
ER -