Translated Abstract
Hollow lattice truss structure is accepted as one of the best candidates under various loading condition, cellular materials with hollow lattice truss topologies exhibit higher compressive strengths than equivalent structures with solid trusses owing to their greater resistance to plastic buckling. In this paper, we explore to further improve the quasi-static and dynamic mechanical performance of conventional hollow pyramidal lattice by proposing the concept of inserting foams into the inclined circular tubes.
In this paper, the quasi-static and dynamic compressive properties of metallic sandwich panels with foam filled hollow pyramidal core are investigated. The specimens，including vertical tube, PMI foam filled vertical tube, hollow pyramidal structure, PMI foam filled pyramidal structure, are fabricated and the mechanical responses of the structures under quasi-static compression are studied experimentally. Meawhile, numerical simulations are carried out by using finite element software ABAQUS. Upon validating the simulation results with experimental measurements, the quasi-static compressive response, energy absorption as well as the collapse modes are systematically investigated and analyzed. In addition, the quasi-staic responses of hollow pyramidal structure and PMI foam filled pyramidal structure are compared under the same mass design constraint, relevant material selection chart was presented. At last, to provide insight into the varying role of foam filler with increasing compression velocity from 10m/s to 200m/s, the crushing response and collapse modes of hollow and PMI foam filled metallic pyramidal-cored sandwich panels were studied.
Obtained results reveal that under quasi-static uniaxial compression, it was found that inserting PMI foams into the interstices of a sandwich panel with pyramidal core increase significantly both its peak strength and energy absorption per unit mass. For the case of same mass design, it is shown that an appropriate foam-tube combination must be selected to improve the compressive properties of the pyramidal structure. Under dynamic crushing, strengthening due to foam insertion and inertial stabilization both act to provide support for the tubes against buckling. At relatively low compression velocities, the struts are mainly strengthened by the foam filler; at high compression velocities, inertia stabilization play a more dominant role.
Corresponding authors email
