Quasi-static bending behavior of sandwich beams with thin-walled tubes as core

• Novel sandwich beams with core made of a series of thin-walled tubes are proposed.
• Experiments of such beams under three-point bending are conducted.
• Analytical models and finite element analysis are performed.

Quasi-static three-point bending tests on sandwich beams with a series of identical thin-walled tubes as core are conducted. Three types of cores are studied, namely, closely arranged identical circular tubes, spaced circular tubes, and spaced square tubes. Relationships between the force and displacement at the mid-span of the sandwich beam are obtained from the experiments. Deformation mechanisms for beams with spaced circular tubes and square tubes are analyzed. FE simulations are also carried out using ABAQUS/EXPLICT and the results are compared well with the experimental and analytical results. Energy absorption and partition are calculated and they match well with the simulation. When the mass of the beams is equal, the smaller the diameter of the tube is, the larger the energy absorption the beam has. Optimized sandwich beam with the square tubes is identified as a more effective structure which has the largest energy absorption of all the structures investigated in this paper.