Evolutionary design of nonuniform cellular structures with optimized Poisson's ratio distribution. (5th March 2018)

• Record Type: Journal Article
• Authors: Han, Yafeng; Lu, Wenfeng
• Is Part Of: Materials & design. Volume 141(2018)
• Page Start: 384
• Page End: 394
• Publication Date: 2018-03-05
• Subjects: Nonuniform cellular structure -- Poisson's ratio -- Evolutionary algorithm -- Re-entrant structure -- Additive manufacturing; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2017.12.047
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: For negative Poisson's ratio (NPR) cellular structures, most previous research focus on the design of unit cells, and then repeat the unit cell to construct uniform cellular structures. However, there is a disadvantage that these structures do not have much design freedom to achieve high-level functions, such as performing a desired deformation. As a solution, an evolutionary design method is proposed to develop nonuniform cellular structures. To conduct this method, the design domain is divided into finite unit cells with tunable Poisson's ratio (PR). With a given objective deformation, the value of each unit cell's PR is optimized using evolutionary algorithm (EA). In order to reduce the computational cost of the algorithm, discrete cosine transform (DCT) is applied to encode the structure for evolving. Considering the geometrical complexity of the optimized nonuniform cellular structures, additive manufacturing (AM) is chosen to build them physically. Both two-dimensional (2D) and three-dimensional (3D) design cases were developed and analyzed to validate the proposed method. The computational and experimental results showed good conformation with each other. Most importantly, this novel design method brings huge potential to NPR cellular structures with high-level functions and much wider applications. Graphic abstract: Image 1 Highlights: Variable Poisson's ratio was easily achieved by modifying interior angel of the traditional reentrant structure. Cellular structures with various deformation properties was built by connecting unit cells with different Poisson's ratio. Evolutionary algorithm guaranteed the Poisson's ratio distribution was optimum for the given objective deformation. Application of "discrete cosine transform encoding" can significantly reduce the computational cost.