Open Access. Powered by Scholars. Published by Universities.®
- Publication
- Publication Type
Articles 1 - 10 of 10
Full-Text Articles in Engineering
Frequency Response And Recovery Of Muscles And Effects Of Wrapping The Lower Leg On Surface Velocity Measurements, Cameron David Smallwood
Frequency Response And Recovery Of Muscles And Effects Of Wrapping The Lower Leg On Surface Velocity Measurements, Cameron David Smallwood
Theses and Dissertations
This thesis is comprised of two studies. The objective of the first study was to find the frequency response and stiffness of the biceps brachii muscle group during recovery from exercise induced damage and to determine whether these data could be used to track muscle recovery by correlating changes in the frequency response with changes in muscle stiffness. Stiffness moduli were collected using Shear Wave Elastography (SWE) which were then applied to a proportional first mode frequency analysis. Data were collected for the muscle stiffness and frequency response for fifteen subjects (25.6 +- 4.5). By comparing the proportion of the …
Experimental And Theoretical Investigation Of Mechanical Response Of Laser-Sintered Diamond Lattice Structures, Clayton Neff, Neil Hopkinson, Nathan B. Crane
Experimental And Theoretical Investigation Of Mechanical Response Of Laser-Sintered Diamond Lattice Structures, Clayton Neff, Neil Hopkinson, Nathan B. Crane
Faculty Publications
Typically additive manufacturing (AM) processes are limited to a single material per part while many products benefit from the integration of multiple materials with varied properties. To achieve the benefits of multiple materials, the geometric freedom of AM could be used to build internal structures that emulate a range of different material properties such as stiffness, Poisson’s ratio, and elastic limit using only one build material. This paper examines the range of properties that can be simulated using diamond lattice structures manufactured from Nylon 12 with a commercial laser sintering process. Diamond lattices were fabricated with a unit cell length …
Controlling Normal Stiffness In Droplet-Based Linear Bearings, Qi Ni, Nathan B. Crane
Controlling Normal Stiffness In Droplet-Based Linear Bearings, Qi Ni, Nathan B. Crane
Faculty Publications
While Capillary forces are negligible relative to gravity at the macroscale, they provide adequate force to effectively manipulate millimeter to micro meter objects. The fluidic actuation can be accomplished using droplets that also act as bearings. While rotary droplet bearings have been previously demonstrated, this paper considers the performance potential of discrete droplets acting as linear bearings. Specifically, it addresses the positioning accuracy of a droplet-based bearing consisting of a droplet between a moving plate and a stationary substrate with constrained wetting region under a normal load using both closed form analytical solutions and numerical simulations. The vertical force and …
Material Selection Shape Factors For Compliant Arrays In Bending, David T. Fullwood, Todd G. Nelson, Jared T. Bruton, Nathan E. Rieske, M. Patrick Walton, Larry L. Howell
Material Selection Shape Factors For Compliant Arrays In Bending, David T. Fullwood, Todd G. Nelson, Jared T. Bruton, Nathan E. Rieske, M. Patrick Walton, Larry L. Howell
Faculty Publications
Similar to the general class of metamaterials, compliant arrays (CAs) are engineered from an array of subelements that combine to produce a response that is typically not available from a at panel made of a single material. As such, analysis and design of CA systems requires the integration of both the material and geometrical properties of the array. This paper proposes a convenient and efficient method of combining these essential elements using analytically derived shape factors for bending modes. The approach is validated experimentally, and used to demonstrate large regions of previously inaccessible property combinations in material selection charts that …
Refinement And Characterization Of Synthetic Vocal Fold Models, Shelby Charisse Ward
Refinement And Characterization Of Synthetic Vocal Fold Models, Shelby Charisse Ward
Theses and Dissertations
Understanding vocal fold mechanics is an integral part of voice research and synthetic vocal fold models are an essential tool in characterizing vocal fold mechanics. These models contain multiple layers with varying stiffness, much like human vocal folds. The purpose of this thesis is to improve the current models and modeling techniques, as well as investigate the impact of asymmetry on model vibration. A new design for an MRI-based model is detailed. This model has a more realistic geometry than the simplified models and mimics some of the vibratory characteristics observed in human vocal folds. The MRI-based model was used …
The Effects Of Wrist Orthoses On The Stiffness Of Wrist Rotations, Daniel Brad Seegmiller
The Effects Of Wrist Orthoses On The Stiffness Of Wrist Rotations, Daniel Brad Seegmiller
Theses and Dissertations
Wrist orthoses are the most common upper limb orthoses, being used by thousands of individuals each year to stabilize, immobilize, or support the wrist joint. Wrist orthoses achieve their function by altering the stiffness of the wrist joint (Figure 1-1). However, there is no quantitative understanding of how wrist orthoses affect wrist stiffness, and consequently, wrist orthosis development often relies on feel, intuition, or empirical heuristics rather than a methodical, quantitative approach. Because wrist movement control is dominated by wrist joint stiffness (Charles and Hogan 2011) a quantitative understanding of how wrist orthoses alter the stiffness of the wrist is …
Passive Stiffness Of Coupled Wrist And Forearm Rotations, Will Brandon Drake
Passive Stiffness Of Coupled Wrist And Forearm Rotations, Will Brandon Drake
Theses and Dissertations
The dynamics of wrist rotations are dominated by joint stiffness, which the neuromuscular system must account and compensate for when controlling wrist movements. Because wrist stiffness is anisotropic, movements in some directions require less torque than movements in others, creating opportunities to follow "paths of least resistance." Forearm pronation-supination (PS) can combine with wrist flexion-extension (FE) and radial-ulnar deviation (RUD) to allow the wrist to rotate in directions of least stiffness. Evaluating this hypothesis, and understanding the control of combined wrist and forearm rotations in general, requires a knowledge of the stiffness (the dominant mechanical impedance) encountered during combined wrist …
A Comparative Study Of Strength And Stiffness Of Thin-Walled Specimens Fabricated By Fdm And 3d Printing Technologies, Miranda Rodrigo
A Comparative Study Of Strength And Stiffness Of Thin-Walled Specimens Fabricated By Fdm And 3d Printing Technologies, Miranda Rodrigo
Theses and Dissertations
Rapid Prototyped part failure constitutes a major issue for both RP providers and customers. When parts fail the reputation of the vendor is heavily deteriorated, customer dissatisfaction increase and replacement of the broken parts is often necessary to avoid the loss of future business. Product design teams often run into situations where Rapid Prototyped parts are not able to withstand shipping and handling and delivered broken or while demonstrating and examining the parts. When done in the face of customers this builds a perception of poor quality and lack of aptitude on the design group as well as the RP …
Characterization And Biomechanical Analysis Of The Human Lumbar Spine With In Vitro Testing Conditions, Dean K. Stolworthy
Characterization And Biomechanical Analysis Of The Human Lumbar Spine With In Vitro Testing Conditions, Dean K. Stolworthy
Theses and Dissertations
Biomechanical testing of cadaveric spinal segments forms the basis for our current understanding of healthy, pathological, and surgically treated spinal function. Over the past 40 years there has been a substantial amount of data published based on a spinal biomechanical testing regimen known as the flexibility method. This data has provided valuable clinical insights that have shaped our understanding of low back pain and its treatments. Virtually all previous lumbar spinal flexibility testing has been performed at room temperature, under very low motion rates, without the presence of a compressive follower-load to simulate upper body weight and the action of …
The Development And Evaluation Of The Knife Finite Element, Brett W. Clark
The Development And Evaluation Of The Knife Finite Element, Brett W. Clark
Theses and Dissertations
This thesis presents the development and evaluation of the knife finite element which is a degenerate case of a hexahedral element. The knife connectivity is an artifact of automatic all-hexahedral mesh generators. Currently, knives are propagated to the surface of the mesh for removal. However since this disturbs the surface mesh, other alternatives are needed. This thesis investigates the option of leaving the knife connectivity in the mesh and treating it as a valid finite element. The shape functions and stiffness matrix for the knife element are derived and evaluated using theoretical and practical evaluations. It is concluded that the …