Topology optimization of microstructure configuration of super-light materials

For super-light materials, based on the application of boundary conditions of macrostructure to those of unit cell with microstructure, topology optimization of the unit cell with microstructure was solved by using the finite element model, variable density approach and optimization criteria method. The optimization model based on volume constraint and strain energy was aimed to gain the unit cell with maximal stiffness. Topology optimization was achieved through repeating the progress of using optimization criteria method, changing the relative density of each element, and saving elements whose density values are lower than the threshold for next step's iterative computation. By adopting the appropriate penalty factor and threshold to control iterative, the convergence rate and precision was improved. Optimization results show that by applying this method, optimal microstructure of the unit cell can be obtained to gain the porous material with maximal stiffness under the same volume constraint, while the cost and the weight of the structure are lowered down.