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Explicit thickness integration for three‐dimensional shell elements applied to non‐linear analysis
Author(s) -
Mahe M.,
Sourisseau J. C.,
Ohayon R.
Publication year - 1993
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.1620360703
Subject(s) - numerical integration , tangent stiffness matrix , tangent , mathematics , displacement (psychology) , matrix (chemical analysis) , stiffness matrix , shell (structure) , stiffness , mathematical analysis , numerical analysis , geometry , structural engineering , materials science , engineering , psychology , composite material , psychotherapist
The problem of multilayered degenerated 3‐D shell elements for which the numerical integration is performed for each ply is that of the high generation time in non‐linear analysis when the number of plies is important. But these elements give accurate results for thin and moderately thick shells, so in order to reduce the generation time explicit thickness integration is investigated. We first write an expansion of the strain‐displacement matrix in power series of the thickness variable in order to obtain explicit expressions of the tangent stiffness matrix and internal force vector, appearing in the non‐linear formulation. Explicit expressions of non‐linear stiffness matrices are presented, using the explicit integration‐first approximation. Simple expressions of several matrices, sub‐matrices and vectors appearing in the formulation are given here in order to obtain an important computing‐time gain. Next, some numerical validation tests comparing the classical element with numerical thickness integration and this one are discussed to prove validity of this formulation.