Experimental investigation of energy absorption of sandwich panels with pyramidal lattice core made by brazing method

The use of lattice structures has always been envisaged by researchers and various industries because of their unique mechanical properties and low weight. One of the main challenges in this area is the manufacturing process of these structures, particularly in mass production and commercialization. Pyramid-metal tubular lattice structures are among the most optimal lattice structures for energy absorption. The connection of tubes to metal plates is one of the main challenges in the construction of these types of structures. In this research, rather than using metal molds and fixtures, the toothed appendages are created by cutting the ends of the tube and place them in the holes of the plates in order to fix the position of the tubes in the brazing process. Mechanical locking of tubes and plates enhances connection strength and structural stiffness. In this study, specimens have been made with various geometries and the effect of geometrical parameters such as the length to diameter ratio of the tube and its angle of orientation on energy absorption were investigated. The manufacturing process used in this research was very efficient and none of the samples were damaged at the joint. Increasing the orientation angle from 45 to 55 increases the specific energy uptake by up to 40%.