Axial Loading Tests and Simplified Modeling of Sandwich Panels with GFRP Skins and Soft Core at Various Slenderness Ratios

作者：Mathieson Hale; Fam Amir^*

来源：Journal of Composites for Construction, 2015, 19(2): 04014040.

DOI：10.1061/(ASCE)CC.1943-5614.0000494

• Sandwich
• Skin
• Soft core
• Foam
• Axial load
• Buckling
• Wrinkling
• Slenderness

Experimental and analytical studies were conducted to investigate the axial strength and failure modes of sandwich panels with glass fiber reinforced polymer (GFRP) skins and soft polyurethane core. A total of 45 specimens of 78 x 150 mm cross-section and of lengths L-e varying from 500 to 2,400 mm [i.e., slenderness ratio (KLe:r) of 15-70, where r is the radius of gyration] were tested concentrically using pin-ends (K = 1). The effects of skin thickness and an internal GFRP rib on axial behavior were studied. The study first assessed the level of out-of-straightness and concluded that all specimens generally fall within an acceptable limit of span/1,000. A model based on sandwich panel theory, accounting for excessive shear deformations of the soft core, was used to predict axial strength at a wide range of KLe:r and then used in a parametric study. It was shown that short panels with KLe:r of 15-17 experienced local failure, outwards skin wrinkling in non-ribbed panels, or skin crushing in ribbed panels. Slender panels with KLe:r of 41-70 experienced global buckling followed by secondary local failure. Panels with intermediate slenderness (17-41) showed mixed failure modes. The load at which local failure governs at low KLe:r appears to be a constant, independent of KL(e)r, whereas the global buckling load decreases significantly with increasing KLe:r. Increasing skin thickness appears to be more effective at high KLe:r whereas increasing core shear modulus appears to be more effective at low KLe:r.

• 出版日期2015-4