Full-field experimental analysis of a sandwich beam under bending and comparison with theories

摘要

Sandwich plates with two thin stiff face-sheets and a soft center core have been used in many constructions for which the dominating load is transverse bending. Many theoreticalumerical analyses have been devoted to studying the deformation mechanism of such a structure. But relatively limited experimental investigations are present in this field and they are often self-content with little connection to the existing theoretical pursuits. In this paper, a composite sandwich structure made with carbon fiber woven face sheets and a relatively compliant foam core was loaded in 3-point bending. Images were captured of the specimen before and after deformation, which were then analyzed with a Digital Image Correlation (DIC) program. The full field displacements and strain fields were obtained for the specimen. The experimental deflection of the beam was compared with five theoretical models and one numerical solution. The result shows that only one model predicts the reality well.