Dr. V. Gupta TU Delft

Mechatronic Metamaterials

This project proposes to combine the two engineering disciplines of mechatronics and metamaterials to create a mechatronic metamaterial (MetaMech) structure for active vibration suppression. This MetaMech structure is characterised by integrating smart material actuators like piezoelectric in a distributed manner into spatially architectured flexible structures (compliant mechanisms). The goal of MetaMech is to overcome (i) the mass limitation in passive damping and force limitation in active damping by an optimized distribution of active and passive material into a lattice metamaterial structure; and to overcome (ii) the fundamental limitations associated with known linear damping methods to enable broadband and/or varying mode suppression by developing adaptive nonlinear vibration suppression methods. If successful, MetaMech will be an adaptive damping material that enables not only the utilisation of compliant mechanisms for highly dynamic motion systems with larger deflections, but also increases the precision and speed of current motion systems that are limited by broadband vibration modes.

This collaborative project involves two academic partners from TU Delft and Twente University, along with four industrial partners: ASML, Demcon, Physik Instrumente (PI) and VDL.

Ultrawide bandgaps by HG lattice metamaterials

Continuous demand for the improvement of mechanical performance of engineering structures pushes the need for metastructures to fulfil multiple functions. Extensive work on lattice-based metastructure has shown their ability to manipulate wave propagation and produce bandgaps at specific frequency ranges. Enhanced customizability makes them ideal candidates for multifunctional applications. We explore a wide range of nonlinear mechanical behavior that can be generated out of the same lattice material by changing the building block into dome-shaped structures, which improves the functionality of the material significantly. We propose a novel hourglass-shaped lattice metastructure that takes advantage of the combination of two oppositely oriented coaxial domes, providing an opportunity for higher customizability and the ability to tailor its dynamic response. Numerical simulation, analytical modelling, additive layer manufacturing (3D printing) and experimental testing are implemented to justify the evaluation of their mechanics and reveal the underlying physics responsible for their unusual nonlinear behaviour.

Inverse design: Indian medieval architectural elements

In this study, we immerse in the intricate world of patterns, examining the structural details of Indian medieval architecture for the discovery of motifs with great application potential from the mechanical metastructure perspective. The motifs that specifically engrossed us are derived from the tomb of I’timad-ud-Daula, situated in the city of Agra, close to the Taj Mahal. In an exploratory study, we designed nine interlaced metastructures inspired from the tomb’s motifs. We fabricated the metastructures using additive manufacturing and studied their vibration characteristics experimen- tally and numerically. We also investigated bandgap modulation with metallic inserts in honeycomb interlaced metastructures. The comprehensive study of these metastructure panels reveals their high performance in controlling elastic wave propagation and generating suitable frequency bandgaps, hence having potential applications as waveguides for noise and vibration control. Finally, we devel- oped novel AI-based model trained on numerical datasets for inverse design of metastructures with a desired bandgap.

Computational Mechanics: Dispersion analysis of the hourglass lattice structure

The concept utilizes elastic wave resonances to form constructive or destructive interference, which creates ranges of frequencies at which waves are either allowed to propagate (pass bands) or blocked in one (stop bands) or multiple directions (complete band gaps (BGs)). The bandgap depends on the geometric configuration and material of the unit cell, stiffness properties of the periodic structure as well as host matrix of the resonating mass, which has been exploited in designing the metamaterial. The unit cell is designed with the hourglass lattice integrated with a cubic resonating mass at the center which helps to induce ultrawide bandgaps with effective mechanical properties. Using various parametric combinations, a detailed bandgap analysis was performed for a spherical and parabolic hourglass-based matrix. After numerical simulation, additive layer manufacturing (3Dā printing) and experimental testing are carried out to evaluate the system and reveal the underlying physics responsible for its unique dynamic behaviour.