Lattice Structures Design Based on Topology Optimization: Modeling, Ad- ditive Manufacturing and Experimental Analysis

Resumo

Materials made with architected microstructures present tunable mechanical properties and can be used to obtain lightweight structures and, at the same time, with high strength. In lattice structures, for example, topology and truss diameter can be varied so that the material is efficiently distributed in the design domain. Due to the complex geometries of these structures, designing them using computer-aided design tools is a challenging task.

In this work, a parametric modeling was developed in the Rhinoceros program using the Grasshopper extension to assist in the construction of models of lattice structures with varying truss diameters. The developed parametric modeling allows defining the topology and the diameter of the truss bars, which greatly simplifies the generation of models of porous solids. Microstructure models were generated and manufactured in polyamide 12 through selective laser sintering to assess whether it is feasible to print the trusses from the established parameters. The problem of a simply supported beam with a concentrated load at the center was solved using the topology optimization method and the density field was used to generate the variable density models. Both regular and variable density beam models have been designed to have the same mass and additively manufactured with the use of the selective laser sintering technique. Experimental analyzes were carried out using three-point bending tests and the results show that the solution using variable density has a large increase in stiffness when compared to solutions with uniform density.