Session: 17-01-01: Research Posters

Paper Number: 149931

149931 - On the Dynamic Behavior of Mechanical Metamaterial With Tunable Frictional Energy Dissipation: Numerical and Experimental Study 

Over the last decades, numerous investigations have been carried out on artificially architectured metamaterials due to their extraordinary physical properties, which cannot be achieved by conventional materials. Among different metamaterial categories, mechanical metamaterials have gained significant attention due to their exceptional properties, including negative bulk modulus, programmable deformation patterns, phononic bandgaps, superior thermoelectric properties, and high specific energy absorption, providing substantial benefits for applications like vibration isolation and impact protection. Energy dissipation metamaterials, such as those that dampen energy through friction, are crucial for effectively controlling excessive vibrations and preventing catastrophic failures due to their ability to dissipate mechanical energy. Despite their innovative designs, additively manufactured metamaterials often face limitations in achieving and optimizing broad bandgaps at specific frequency ranges where wave propagation is effectively blocked. These limitations arise primarily due to the complex interactions between material geometry, mechanical properties, and wave dynamics, which are further complicated by non-linear effects such as frictional contacts. While existing studies have made significant strides in exploring the theoretical and idealized aspects of metamaterials, they often fall short in addressing the complexities introduced by energy dissipation mechanisms such as frictional interactions. This oversight results in a substantial knowledge gap, as the real-world behaviors of these materials under practical conditions are not adequately captured. Frictional forces can introduce non-linearities and additional damping mechanisms that significantly alter the wave propagation characteristics of metamaterials. These interactions can either enhance or diminish the effectiveness of the bandgaps in blocking specific frequency ranges and change the intensity of attenuation of elastic waves passing through the metamaterial, thereby impacting the material's overall performance. Current research tends to simplify or overlook these frictional effects, focusing instead on idealized models that do not fully account for the nuances of practical deployment. In the proposed study, the elastic wave dispersion characteristics of a programmable mechanical metamaterial with tunable frictional energy dissipation are investigated. To achieve this objective, a comprehensive computational finite element analysis is performed using COMSOL Multiphysics software. The designed metamaterial employs Coulomb friction for energy dissipation, activated when a small gap closes, causing two walls to slide across one another under planar loading conditions. The investigation begins with a frequency domain analysis without friction to establish baseline wave dispersion characteristics and identify inherent bandgaps. Following this, time-dependent simulations assess the impact of various friction coefficients on wave attenuation and energy dissipation, capturing the dynamics between frictional forces and elastic waves. Furthermore, systematic experimental studies were performed on the additively manufactured metamaterials to assess the agreement between experimental and numerical results by analyzing the transmission loss diagrams.

Keywords: Frictional Energy Dissipation, Mechanical Metamaterial, Wave propagation, Finite-element analysis

Presenting Author: Fatemeh Delzendehrooy Iowa State University

Presenting Author Biography: Fatemeh Delzendehrooy is a current aerospace engineering (engineering mechanics) student at Iowa State University. She holds a M.Sc. in Aerospace Engineering specializing in Structural Design from Iran University of Science and Technology and a B.Sc. in Mechanical Engineering from Shiraz University. Her research areas include experimental and computational material characterization, additive manufacturing, fracture mechanics, and composite structures.

Authors:

Fatemeh Delzendehrooy Iowa State University
Carson Willey Air Force Research Laboratory
Vincent Chen Air Force Research Laboratory
Abigail T. Juhl Air Force Research Laboratory
Azadeh Sheidaei Iowa State University