Elastic-Plastic Wrinkling of Sandwich Panels With Layered Cores

Abstract

Elastic-plastic wrinkling of compression loaded sandwich panels made with layered cores was studied analytically and experimentally. A core with a stiff layer near the sandwich skins can improve various properties, including wrinkling and impact strengths, with only a minor weight penalty. The 2D plane stress and plane strain bifurcation problems were solved analytically, save for a determinantal equation which was solved numerically. Experiments were performed on aluminum skin/foam core sandwich panels with different combinations of stiff and soft core materials. Good correlation between experiments and theory was obtained.

Symmetrical Facing Wrinkling of Composite Sandwich Panels

“…The similar equations that differ from each other by numerical factor can be found in the well-known monographs and handbooks [3][4][5][6][7] as well as in some recent studies [8,[10][11][12][13][14][15][16][17][18][19].…”

“…Grenestedt and Danielsson [16] studied elastic and elastic-plastic skin wrinkling of graded and layered foam core sandwich panels.…”

Imperfection-induced Wrinkling Material Failure in Sandwich Panels

“…The most obvious one is general for all the stability problems solved by the linear methods -there is no account for any type of initial imperfections. Most reported experimental results on the wrinkling failure of sandwich panels show that the classical wrinkling formulae provide the correct trends, but with a nonconservative load or stress prediction, e.g., [1,10,11].…”

Wrinkling in sandwich panels – an analytical approach

“…The first approaches to treat wrinkling failure has already been taken in 1930s [1,2]. Further, this failure mode has been investigated in many studies and a number of solutions, mostly in linear-elastic 2D formulation, were proposed, for example [3][4][5][6][7][8][9][10][11][12][13][14] (the list of references can easily be continued). The studies dealing with 3D case have received less attention, and references [15][16][17][18][19][20][21][22][23][24][25][26] seem to fill the list of available solutions.…”