Michael R. Bonthron

Michael R. Bonthron

PhD Student in Mechanical Engineering

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A list of all the posts and pages found on the site. For you robots out there is an XML version available for digesting as well.

Pages

Posts

Future Blog Post

less than 1 minute read

Published:

This post will show up by default. To disable scheduling of future posts, edit config.yml and set future: false.

Blog Post number 4

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

Blog Post number 3

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

Blog Post number 2

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

Blog Post number 1

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

portfolio

publications

talks

Transition Waves in Multistable Mechanical Metamaterials under Periodic Excitation

Published:

Multistable mechanical metamaterials have recently provided unique platforms with wave guidance and wave steering capabilities. Arrays of symmetric/asymmetric bistable elements, such as elastically/plastically deformed arches, can be patterned to control the signal transmission and to passively achieve nonreciprocal wave propagation. In this work, sequential nonlinear transition wavefronts will be obtained by imposing an oscillatory transverse displacement to an element of a multistable metamaterial made of one-dimensional array of arches. Different excitation amplitude and frequencies will be considered and it will be showed how these features can be harnessed to control transition wavefronts propagation. In addition, the effect of multiple oscillatory inputs at different positions of the array will be investigated. The dynamics of the system will be theoretically studied by solving the continuum equations of motion with both direct time integration methods and numerical continuation techniques (i.e., pseudo-arclength continuation). Nonlinear wave interference, collision-like cases, and internal resonance phenomena will be characterized based on different oscillatory excitation parameters. This study will open avenues to the use of dynamic inputs to control sequential transition wavefronts in mechanical metamaterials

Porous Metamaterials with Twofold Buckling Instability

Published:

Soft porous metamaterials with periodically-distributed pores are commonly known for their auxetic behavior. This nonlinear response is the result of a short-wavelength global buckling mode under compressive loading. Unlocking new pathways to trigger global buckling mode shapes with different pores rearrangements could open new avenues for developing intelligent, programmable, and multifunctional devices. In this work, we explore a novel soft porous metamaterial that demonstrates different short-wavelength global buckling modes under positive and negative pressure. We investigate the design space to characterize this twofold buckling instability and post-buckling behavior by varying the geometric parameters of the porous metamaterial. Our investigation includes analytical critical buckling pressures, numerical simulations, and experimental validation of manufactured metamaterials tested upon inflation and deflation. In terms of applications, we demonstrate the superior capability of the pneumatically-driven metamaterial to selectively grasp slender objects with preprogrammed mode shapes. Leveraging both positive and negative pressure for actuation purposes introduces a new class of programmable buckling-based soft actuators with highly tunable reconfiguration patterns.

Chaotic Motion in Multistable Mechanical Metamaterials under Periodic Excitation

Published:

Multistable mechanical metamaterials (MMM) have demonstrated wave guidance capabilities, energy harvesting, and mechanical computing by arranging multistable unit cells into arrays. The transition between stable configurations of MMM has primarily been activated and modeled considering quasi-static forcing. In this work, transverse oscillatory loads are used to manipulate the response of a one-dimensional chain of bistable arches. By varying the magnitude and frequency of excitation, we tailor the motion of the structure with respect to its stable equilibrium states. We reveal regions within the parameter space ranging from intrawell motion constrained to a single energy well to periodic and chaotic interwell motion which vacillates between multiple energy wells. The dynamics of the nonlinear system will be analytically studied by solving the continuum equations of motion with direct time integration methods, numerical continuation techniques (pseudo-arclength continuation), and methods from dynamic analysis (Lyapunov Exponents). This study will open avenues to designing and reprogramming structures to exhibit or prohibit large motion for programmable bands of input magnitude and frequencies.

teaching