Effect of lattice dimensions on bending properties of sandwich structures

With the development of additive manufacturing methods, the mechanical performance and weight reduction studies of sandwich structures formed with different beam structure models have become easier. There are many options to achieve the best mechanical performance, such as changing the plate or core structure material, as well as changing the distribution or shape of the material. Fused Deposition Modelling (FDM) is a process with flexibility, simple processing, short production time, opportunity for custom design and the ability to increase the functionality of honeycomb sandwich structures. 3D printers working on the principle of Fused Deposition Modelling (FDM) are one of the most frequently applied methods in additive manufacturing technologies with the use of thermoplastic materials such as PLA and ABS. In this study, three-point bending tests of five different sandwich structures formed by using 7075 aluminium plates and bonding the core structure material prepared by FDM method from PLA filament with biodegradable material with resin were performed. In this study with rectangular lattice design, it is aimed to create an idea for other two-dimensional truss structures of different shapes. The area of the truss structure was kept the same and its mechanical performance was analysed by changing the size of its edges. The lattice areas of the specimens are 12 mm². While the truss structure of one of the specimens is square, the other four truss structures are formed by horizontal and vertical positioning of two rectangles of the same dimensions. According to the test results, it was seen that the number of beams in the direction perpendicular to the force has a significant effect on the force it provides, while the vertically positioned ones show a considerably lower performance compared to the others.