A SMOOTHED STRAIN BASED ELEMENT FOR GEOMETRICALLY NONLINEAR ANALYIS OF PLATE/SHELL STRUCTURES
This paper reports the development and application of the assumed strain smoothing method for geometrically nonlinear analysis of plate/shell structures using a bilinear quadrilateral flat element. The von Karman’s large deflection theory and the Total Lagrangian (TL) approach are utilized in the small strainlarge deformation formulation within the context of the first-order shear deformation theory (FSDT). The most important feature of the developed element is the evaluation of linear membrane-bending and nonlinear geometric stiffness matrices based on integrations along the boundaries of smoothing elements. This technique can give more accurate numerical integrations even with badly shaped elements or coarse discretization. Several numerical examples have been carried out and the present element is found to yield excellent results in comparison with other available finite element solutions as well as theorical/experimental results. It is also observed that the present element is able to offer good prediction in geometrically nonlinear analysis of thick to moderately thin plates/shells without shear-locking. The success of the present flat/shell element provides a further demonstration of efficient flat quadrilateral elements for nonlinear analysis.