Topological optimization of thin elastic metamaterial plates for ultrawide flexural vibration bandgaps. (15th March 2023)

• Record Type: Journal Article
• Authors: Yan, Gengwang; Yao, Song; Li, Yingli; Zhou, Wenxi
• Is Part Of: International journal of mechanical sciences. Volume 242(2023)
• Publication Date: 2023-03-15
• Subjects: Elastic metamaterial plates -- Topology optimization -- Adaptive genetic Algorithm -- Plane wave expansion method -- Finite element method -- Vibration attenuation; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2022.108014
• Languages: English
• ISSNs: 0020-7403

Abstract

Highlights: The combined AGA/IFPWEM optimization algorithm is proposed to efficiently design thin EMs plates with ultrawide FVBGs. The effects of initial topologies and material volume fraction constraint on the unit cell optimization are explored. The physical mechanisms including the iso-frequency contours, the phase, and group velocities are studied. The flexural wave propagation in finite-size lattices composed of optimized unit cells is investigated numerically and experimentally. ABSTRACT: The properties of bandgaps (BGs) for manipulating elastic/acoustic waves are highly determined by the spatial distribution of materials in the primitive unit cell. In this work, the topological optimization strategy is implemented to design thin elastic metamaterial plates to broaden the total relative width of flexural vibration bandgaps (FVBGs). It is formulated based on the adaptive genetic algorithm (AGA) and solved using the improved fast plane wave expansion method (IFPWEM), which can contribute to improving the efficiency of optimization. The effects of initial designs and material volume fraction constraints on the optimization are discussed in detail. Based on the optimized solutions evolved from Initialization IV and volume fraction constraint f 0 = 0.25, the wave propagation (iso-frequency contours, the phase, and group velocities) is utilized to investigate the physical mechanisms. The numerical and experimental results of the finite-size lattices composed of optimized unit cells demonstrate that out-of-plane flexural waves can be transmitted or prohibited, which is in perfect match with the predicted results of band structures. Additionally, the present methodology is expected to explore their potential application in the vibration attenuation of the two-component thin elastic metamaterials plates. Graphical abstract: Image, graphical abstract