Effect of Resin Pins on the Failure Behavior of Foam Core Sandwich Beams under Three-Point Loading

Studies show limitations in increasing the mass fraction of resin pins in aviation components. The main objective of the present study is to investigate the effect of resin pins with different diameters and numbers on the bending performance and damage mode of sandwich structures with a constant mass fraction of resin pins. The obtained results show that the phi 2 specimen (i.e., the diameter of the resin pin in the sample is 2 mm) increases the load-bearing capacity by 41.8%. The deformation process of sandwich beams with and without resin pins is similar. However, the failure modes are different due to the diameters, amounts, and spacing of resin pins. Moreover, the uncertainty analysis of the experimental results is carried out by CT three-dimensional reconstruction of foam and finite element method (FEM). The obtained results show that the resin absorbed by the cells on the foam surface is the primary source of simulation errors. To resolve this problem, a new method is proposed to estimate the range of experimental results and improve the simulation accuracy by compensating for the diameter of the resin pin.