Shape Optimization of Tunable Poisson's Ratio Metamaterials With Disk B-Splines

We propose an explicit representation method using disk B-splines for Poisson's ratio metamaterial design. Disk B-spline representation generalizes the concept of the B-spline control point into a control disk, enhancing the ability to manipulate both the shape and thickness of the region. Therefore, this representation is frequently employed for shape optimization. The optimized metamaterials described by disk B-spline are decomposed into a sequence of circles constructing one implicit function. A novel optimization model based on disk B-spline representation is proposed, and the homogenization theory is used for calculating effective Poisson's ratio (PR). The numerical examples contained missing rib metamaterials, petal-like metamaterials, and extreme PR metamaterials, which are studies to illustrate the advantages and effectiveness. By explicitly manipulating the parameters of the disk's B-spline, a broad spectrum of unexpectedly negative Poisson's ratio from -0.1 to -0.9 sequences can be achieved, and arbitrary Poisson's ratios structures can be obtained through interpolating continuous parameters. It's also extended to encompass 3D structures. We validate the accuracy of our results by comparing them with simulations performed using commercial software.