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oai:figshare.com:article/34023864 2026-09-29T13:18:35Z category_26536 category_28813 category_30289 category_26755 category_30142 category_29212 category_25789 category_24964 category_26764 category_26770 category_26779 category_26773 category_29776 category_30127 category_29812 category_29224 category_29815 category_29821 category_26533 category_29011 category_24979 category_24988 category_25012 category_24973 category_24994 category_25168 item_type_14 month_year_09_2026

Shape Optimization for the Design of Linear and Nonlinear Metamaterials to Improve Nonlinear Ultrasonic Testing — NDE 2021 Conference Talk [Video Presentation] Pravinkumar Ghodake (3701242) Engineering education Applications in physical sciences Other physical sciences not elsewhere classified Acoustics and noise control (excl. architectural acoustics) Acoustics and acoustical devices; waves Computational complexity and computability Computational modelling and simulation in earth sciences Data visualisation and computational (incl. parametric and generative) design Mechanical engineering asset management Numerical modelling and mechanical characterisation Mechanical engineering not elsewhere classified Solid mechanics Theoretical and applied mechanics Nonlinear optics and spectroscopy Numerical analysis Numerical computation and mathematical software Numerical solution of differential and integral equations Numerical and computational mathematics not elsewhere classified Engineering design Computer aided design Design practice and methods Industrial and product design Design not elsewhere classified Design history, theory and criticism Models and simulations of design Theory and design of materials SHAPE OPTIMIZATION shape optimization algorithms shape optimization computations Shape optimization shape optimization Shape Optimization nonlinear ultrasonics Nonlinear ultrasonics Nonlinear Ultrasonics linear metamaterials Nonlinear Metamaterials nonlinear metamaterials harmonic scattering harmonic scattering intensities Harmonic Scattering Angle-resolved Harmonic Scattering phononic crystals Phononic Crystals Phononic crystals bandgap bandgap bulk material bandgap calibration curves Finite Element AnalysisAlthough COMSOL comsol studies MATLAB non-gradient optimization ultrasonic testing Ultrasonic testing -- Equipment and supplies Ultrasonic testing -- Research Ultrasonic Testing (UT) Ultrasonic Testing Ultrasonic testing ultrasonic testing of concrete NDE 2021 ISNDT ISNDT Virtual Conference eJNDT NDT steel-glass layered metamaterials second harmonic suppression parasitic harmonics structural health monitoring Structural Health Monitoring (SHM). Structural health monitoring systems Structural health monitoring Aircraft availability Structural health monitoring; Interfacial debonding; ACTs; Vibration-based Structural Health Monitoring Sensors Structural health monitoring. Structural Health Monitoring (SHM) structural health monitoring (SHM) Structural health monitoring (SHM) Structural health monitoring structural health monitoring, data-driven methods, thermal response, bridges Structural health monitoring; Hybrid ceramic bearings; Systematic review; Meta-Analysis Structural Health Monitoring STRUCTURAL HEALTH MONITORING Pravinkumar Ghodake Pravinkumar Ramchandra Ghodake Design Optimization Design & Technology Generative design research Elastodynamics simulations Composite materials Fiber Metal Laminates Impact mechanics This conference contribution is a research presentation delivered by Pravinkumar Ghodake (Department of Mechanical Engineering, IIT Bombay) at NDE 2021 — Virtual Conference & Exhibition, organized by the Indian Society for NDT (ISNDT), 09–11 December 2021. The work was published in the e-Journal of Nondestructive Testing (eJNDT), ISSN 1435-4934, Vol. 27(4), Special Issue, Session: Advanced Ultrasonic NDE-Metamaterials. Title of contribution: "Shape Optimization for the Design of Linear and Nonlinear Metamaterials to Improve Nonlinear Ultrasonic Testing" Abstract: Monochromatic ultrasonic bulk waves generate higher harmonics when they interact with early-stage damages such as dislocations, dislocation substructures, and microcracks. During nonlinear ultrasonic experiments, system-generated higher harmonics — mainly due to instrumentation, transducers, non-uniform and inconsistent clamping force, and couplant effects — are also sent through the testing specimen, resulting in masking of the pure harmonic response due to the damages present inside the material. To stop such system-generated higher harmonics, layered metamaterials are commonly used due to the formation of bandgaps. During the design of such phononic devices, calculation of the optimal geometric parameters — such as the thickness of individual layers of different materials and the total thickness of the phononic device — is challenging and time-consuming due to large sets of parametric sweeps.In this study, a shape optimization problem is defined for the design of linear and nonlinear phononic devices to stop a wide range of higher harmonics. Steel and glass are selected due to their possible bandgap structure. The shape optimization problem is solved using non-gradient algorithms with the main objective of reducing amplitudes of the higher harmonics (2f, 3f, and 4f). Even though the amplitudes of the higher harmonics (3f, 4f) are lower, as we try to stop energy corresponding to 2f after optimization, the phononic device might divert this energy to other harmonics such as 1.5f, 2.5f, 3f, 3.5f, and 4f. The linear and nonlinear wave propagation problems are solved using COMSOL finite element software, and the optimization loop is added by integrating MATLAB and COMSOL. The stopping of the higher harmonics is demonstrated after using the obtained optimal solution of the shape optimization problems. The process of solving the forward finite element problem and then solving an inverse problem of finding the optimal layer thicknesses — by applying weak constraints on the total thickness of the metamaterial lattice — is fully automated. Various computational studies are carried out to demonstrate the applicability of the proposed approach for the design of linear and nonlinear metamaterials. In some cases, the design of linear metamaterials is sufficient, as the same can be used as a nonlinear metamaterial. Complete flexibility in the optimization can be added by optimizing all three variables: the thickness of steel and glass in a periodic structure, and the final thickness of the metamaterial based on the number of repeated periodic structures. Talk outline / timestamps: 0:00 Introduction to Nonlinear Ultrasonic Testing and Parasitic System Harmonics 2:15 Motivation: Masking Effects Caused by Instrumentation, Transducers, and Couplants 4:30 Phononic Bandgaps and Layered Metamaterial Design Principles 6:45 Formulation of the Shape Optimization Problem for Linear and Nonlinear Devices 9:10 Numerical Implementation: Coupling MATLAB and COMSOL for Automated Optimization 11:35 Results: Harmonic Suppression (2f, 3f, 4f) and Optimal Steel-Glass Layer Thicknesses 13:50 Conclusion and Summary of Applicability in NDE Video: <a href="https://youtu.be/PyJpewnetOQ" target="_blank" rel="noreferrer">https://youtu.be/PyJpewnetOQ</a> Published article (<a href="https://ndt.net/" target="_blank" rel="noreferrer">NDT.net</a> / eJNDT): <a href="https://www.ndt.net/search/docs.php?id=26801" target="_blank" rel="noreferrer">https://www.ndt.net/search/docs.php?id=26801</a> Research portfolio: <a href="https://sites.google.com/view/pravinkumarghodake/research" target="_blank" rel="noreferrer">https://sites.google.com/view/pravinkumarghodake/research</a> Note: This is a 14 min 37 sec conference presentation summarizing peer-reviewed research published in the e-Journal of Nondestructive Testing (eJNDT), linking advanced optimization techniques with structural wave mechanics. Keywords: shape optimization, nonlinear ultrasonics, linear metamaterials, nonlinear metamaterials, harmonic scattering, phononic crystals, bandgap, finite element analysis, COMSOL, MATLAB, non-gradient optimization, ultrasonic testing, NDE 2021, ISNDT, eJNDT, structural health monitoring 2026-09-29T13:18:35Z Text Conference contribution 10.6084/m9.figshare.34023864.v1 https://figshare.com/articles/conference_contribution/Shape_Optimization_for_the_Design_of_Linear_and_Nonlinear_Metamaterials_to_Improve_Nonlinear_Ultrasonic_Testing_NDE_2021_Conference_Talk_Video_Presentation_/34023864 CC BY 4.0