Flexural properties of stitched sandwich structure beam with different modulus in tension and compression

In order to establish a theoretical prediction method of position of neutral plane and flexural stiffness for stitched sandwich structure beam with characteristics of different elastic modulus in tension and compression, and verify the effectiveness of the method through related experiment. Firstly, the stitched sandwich structure beam was looked as a quasi-layered structure, taking the characteristics of different modulus in tension and compression as well as different geometry on the top and bottom panel of materials into consideration, a modified Reissner plate theory was developed to evaluate the flexural stiffness and neutral plane position. Secondly, three-point flexural test of stitched sandwich structure beam was carried out, and digital image correlated (DIC) method was also adopted to measure the position of neutral plane. Finally, theoretical predictions were performed for flexural stiffness and position of neutral plane. The results show that theoretical prediction values are in good agreement with experimental data, which demonstrate the validity of the theoretical prediction method.