<Ogirinal>Tensile Shear Creep Test of Steel-Balsa-Steel Sandwich Panel as Floor Deck (I) : Stress Distribution and Deformation of Specimen

Abstract

Stress analysis by finite element method of tensile shear test specimens of steel-balsa-steel sandwich panel for creep test was made statically. The stress distribution of five different shapes of sandwich panel specimens, two of them in accordance with ASTM-C-273, were analysed through the calculation of normal stress (σ_Y), maximum principal stress (σ_1), shear stress (τ_XY) and principal shear stress (τ_max). The presence of stress singularities at the reentrant corners made by specimen and loading plates suggests fracture occurance in balsa core near the corner. Stress intensity factors (KA) in balsa core near the corner were calculated under assumption of similarity with that in homogeneous body. The results obtained were as follows: 1) σ_Y, σ_1 and τ_max of balsa core concentrated near the reentrant corners, and τ_XY distribution was uniform throughout the balsa core, 2) Comparing K_A of various specimens it was suggested that the estimated fracture load on specimens shaped within the range specified by ASTM standard (length l/thickness t≧12) did not vary. Fracture load of specimens with l/t=8.2, 6.3 and 4.2 were lower than those of the standard specimens. Therefore, the standard shape will be utilized in the further investigation: tensile shear creep test of sandwich panel as floor deck (II).