Elastic Foundation Analysis of Tilted Sandwich Debond (TSD) Specimen

Abstract

The tilted sandwich debond (TSD) specimen for characterizing debonding of a sandwich structure is analyzed using elastic foundation theory. The face sheet is considered as a cantilever beam in the debonded region of the specimen and as a beam of finite length supported by an elastic foundation in the bonded region. An analytical model for the beam deflection is developed that may be utilized for design of the specimen, fracture analysis, and data reduction of face/core debond toughness. A parametric investigation was conducted to examine how material and geometrical parameters of the constituents of the sandwich and test configuration influence the compliance of the TSD specimen. Testing was performed on a sandwich consisting of glass/vinylester face sheets over a H200 PVC foam core. The compliance predictions for this and a previously examined sandwich agreed favorably with experimental data over a large range of crack lengths and tilt angles. The debond toughness reduced from experimentally calibrated compliance and from the foundation model was consistent.