Abstract This paper presents a new experimental procedure based on Digital Projection Moiré (DPM) for analyzing the non-linear behaviour of sandwich beam with compliant foam core. This kind of core is very flexible relative to the face sheets. Its behaviour is associated with localized effects in the form of displacements and stresses. These effects in turn influence the overall behaviour of the sandwich beam. In this study, the three-point bending results of sandwich beam are in agreement with FEA results obtained using the ABAQUS finite element code. The theoretical predictions based on the high-order sandwich panel theory (HSAPT) are also in good agreement with the experimental and FEM results. It is shown that the results from the proposed procedure are very accurate. Furthermore, it is suggested that the present method is advantageous for whole-field testing for many applications in evaluation of composite materials and sandwich structures and is more user-friendly.