Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding

Spatially constrained soft structures under dynamic perturbation may evolve into a variety of organized morphological patterns such as wrinkles and random folds. These surface transformations are usually triggered by system bifurcation instabilities and regulated by energy redistribution. Among them...

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Main Author: Du, Huifeng
Other Authors: Fang, Nicholas X.
Format: Thesis
Published: Massachusetts Institute of Technology 2023
Online Access:https://hdl.handle.net/1721.1/147375
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author Du, Huifeng
author2 Fang, Nicholas X.
author_facet Fang, Nicholas X.
Du, Huifeng
author_sort Du, Huifeng
collection MIT
description Spatially constrained soft structures under dynamic perturbation may evolve into a variety of organized morphological patterns such as wrinkles and random folds. These surface transformations are usually triggered by system bifurcation instabilities and regulated by energy redistribution. Among them, elastomeric materials sliding on smooth surfaces generate separation pulses due to tangential stress gradients. When the material slides at a speed much lower than those of elastic surface waves, the process is dominated by surface adhesion and relaxation effects coined as Schallamach waves. In contrast, fast traveling separation pulses at the sliding interface exceeding the Rayleigh and shear wave velocities have been theoretically conjectured but not experimentally validated. Besides, the highly dynamic nature of the problem requires a combination of different methods to understand the instability generation mechanisms and evaluate the system responses. Therefore, the purpose of this research is to advance the understanding of the dynamic behavior of instability-triggered detachment waves, and to establish a methodology for more quantitative analyses of the wave propagation, energy transformation and its physical impacts on the surrounding media. Through a synergistic effort combining analytical studies, numerical simulation and experimental observations, we established a framework suitable for the description of: i) mechanisms governing the formation and evolution of separation pulses induced by frictional contact; ii) the necessity and effectiveness of our combined approaches to address the highly nonlinear, multi-scaled dynamic problem; iii) quantitative analysis of the transient wave properties of intersonic surface detachment, and the transformation of energies into other forms (acoustic radiation) during wave propagation in space, and iv) important implications of this work and insights into how the new understanding could shift the landscape of structural design for applications involving soft material contact.
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spelling mit-1721.1/1473752023-01-20T03:04:56Z Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding Du, Huifeng Fang, Nicholas X. Massachusetts Institute of Technology. Department of Mechanical Engineering Spatially constrained soft structures under dynamic perturbation may evolve into a variety of organized morphological patterns such as wrinkles and random folds. These surface transformations are usually triggered by system bifurcation instabilities and regulated by energy redistribution. Among them, elastomeric materials sliding on smooth surfaces generate separation pulses due to tangential stress gradients. When the material slides at a speed much lower than those of elastic surface waves, the process is dominated by surface adhesion and relaxation effects coined as Schallamach waves. In contrast, fast traveling separation pulses at the sliding interface exceeding the Rayleigh and shear wave velocities have been theoretically conjectured but not experimentally validated. Besides, the highly dynamic nature of the problem requires a combination of different methods to understand the instability generation mechanisms and evaluate the system responses. Therefore, the purpose of this research is to advance the understanding of the dynamic behavior of instability-triggered detachment waves, and to establish a methodology for more quantitative analyses of the wave propagation, energy transformation and its physical impacts on the surrounding media. Through a synergistic effort combining analytical studies, numerical simulation and experimental observations, we established a framework suitable for the description of: i) mechanisms governing the formation and evolution of separation pulses induced by frictional contact; ii) the necessity and effectiveness of our combined approaches to address the highly nonlinear, multi-scaled dynamic problem; iii) quantitative analysis of the transient wave properties of intersonic surface detachment, and the transformation of energies into other forms (acoustic radiation) during wave propagation in space, and iv) important implications of this work and insights into how the new understanding could shift the landscape of structural design for applications involving soft material contact. Ph.D. 2023-01-19T18:48:59Z 2023-01-19T18:48:59Z 2022-09 2022-11-04T16:31:41.434Z Thesis https://hdl.handle.net/1721.1/147375 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Du, Huifeng
Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding
title Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding
title_full Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding
title_fullStr Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding
title_full_unstemmed Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding
title_short Dynamic Studies of Instability-Triggered Intersonic Surface Detachment Waves in Soft Material Sliding
title_sort dynamic studies of instability triggered intersonic surface detachment waves in soft material sliding
url https://hdl.handle.net/1721.1/147375
work_keys_str_mv AT duhuifeng dynamicstudiesofinstabilitytriggeredintersonicsurfacedetachmentwavesinsoftmaterialsliding