Three-point Bending Behavior Of Aluminum Foam Sandwich

Aluminum foam sandwich (AFS) can take advantage of the excellent properties of aluminum foam, and improve the insufficient strength of the aluminum foam for the practical application. So the aluminum foam sandwich beams have been widely applied in many fields. An important performance of sandwich beam structure is its resistance to bending performance. In order to have a research on bending deformation and failure modes of aluminum foam sandwich beam, in this paper, we setting the size of aluminum foam sandwich beam and related parameters for the bending test refer to the ASTM standard. And the effects of the structure parameters of sandwich beam such as core thickness, panel thickness and core structure on the static three-point bending properties and deformation behaviors of aluminum foam sandwich beams were investigated. The research are outlined as following:(1) The effects of the sandwich structure on the three-point bending properties of aluminum foam sandwich beams.The bending properties of aluminum foam sandwich beams by static three-point bending test were investigated by experimental method. The following results are found in this test:1) The sandwich structure can significantly improve the flexural properties of aluminum foam in three-point bending test. The load-deflection curve of AFS under static three-point bending is similar to that of aluminum foam. The load-deflection curve of AFS is significantly higher than the sum of foam core and its panels.2) The load-deflection curve of studied AFS in this paper exhibited three regions:a linear region, a rapid load drop region and a plateau region.(2)The effects of the core thickness on the three-point bending properties of aluminum foam sandwich beams.The bending properties of aluminum foam sandwich beams with the same panel thickness and different core thickness were investigated. Found that:1) in the three-point bending test, with the increase of the foam core thickness, the load has smaller decline in rapid load drop region, and plateau region appears early, and the limit loads were taken at the displacement about1.5mm to3mm.2) The limit load and bending stiffness increases with the increase of the panel thickness, and the bending load decreases with the increase of the foam core thickness.3) With the increase of the panel thickness, the failure mode of sandwich beams transition from indentation to core shear failure mode.(3) The effects of the panel thickness on the three-point bending properties of aluminum foam sandwich beams.The bending properties of aluminum foam sandwich beams with the same core thickness and different panel thickness were investigated. Found that:1) The limit load, bending stifness, and bending strength increase with the increase of the panel thickness.2) With the increase of the thickness of the panel, the load-deflection curve have less wave, and the effect of insufficient strength of the core to the deformation of sandwich beams increases.(4) The effects of the core structure on the three-point bending properties of aluminum foam sandwich beams.The bending properties of aluminum foam sandwich beams with different core structure were investigated. Found that:1)The bending properties of the aluminum foam sandwich beam which has a adhesive interface that perpendicular to the compression direction in its foam core is poor, and the bending properties of the aluminum foam sandwich beam which has a adhesive interface that parallel to the compression direction in its foam core is better.2) In practical application, we can use the foam core which has a adhesive interface that perpendicular to the compression direction to replace the whole foam core.