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Full-Text Articles in Engineering
Midfoot Motion And Stiffness: Does Structure Predict Function?, Kirk Evans Bassett
Midfoot Motion And Stiffness: Does Structure Predict Function?, Kirk Evans Bassett
Theses and Dissertations
In clinical settings, dynamic foot function is commonly inferred from static and passive foot measurements; however, there is little evidence that static foot structure can predict dynamic foot function during walking gait. Previous research seeking to find correlations between the two have focused primarily on sagittal plane midfoot angles even though the midfoot has triplanar motion, which misses potentially important information. Additionally, the focus on kinematics alone may miss the contributions that forces play in midfoot mechanics. To address the angle limitations, a novel Signed Helical Angle (SHA) was developed to capture the triplanar motion of the midfoot from a …
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 …
Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones
Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones
Theses and Dissertations
Finite element models were created in Abaqus 6.14 to characterize the rotational stiffness of shallowly embedded column-foundation connections. Scripts were programmed to automate the model generation process and allow study of multiple independent variables, including embedment length, column size, baseplate geometry, concrete modulus, column orientation, cantilever height, and applied axial load. Three different connection types were investigated: a tied or one part model; a contact-based model; and a cohesive-zone based model. Cohesive-zone modeling was found to give the most accurate results. Agreement with previous experimental data was obtained to within 27%. Baseplate geometry was found to affect connection stiffness significantly, …
Simple Models For Estimating The Rotational Stiffness Of Steel Column-To-Footing Connections, Joshua Edwin Tryon
Simple Models For Estimating The Rotational Stiffness Of Steel Column-To-Footing Connections, Joshua Edwin Tryon
Theses and Dissertations
Despite the crucial role they play in transferring loads from the superstructure to the foundation, steel column-to-footing connections have received little attention in research. Though shallow embedded connections are typically characterized as pinned, studies have shown that they exhibit significant rotational stiffness. The objective of this thesis is to quantify the rotational stiffness of such connections. A method named the continuum model is developed by which the rotational stiffness of embedded connections may be calculated. Outputs from this model are compared with experimental data on steel connections embedded in concrete. The continuum model is shown to be capable of reasonably …
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 …
Effect Of High Percentages Of Reclaimed Asphalt Pavement On Mechanical Properties Of Cement-Treated Base Material, Jacob Clark Tolbert
Effect Of High Percentages Of Reclaimed Asphalt Pavement On Mechanical Properties Of Cement-Treated Base Material, Jacob Clark Tolbert
Theses and Dissertations
Full-depth reclamation (FDR) is an increasingly common technique that is used to rehabilitate flexible pavements. Implementation of FDR on rehabilitation projects produces several desirable benefits. However, these benefits are not fully realized due to the fact that state department of transportation specifications typically limit the reclaimed asphalt pavement (RAP) content of pavement base material to 50 percent. The objective of this research was to evaluate the effects of RAP content, cement content, temperature, curing time, curing condition, and moisture state on the strength, stiffness, and deformation characteristics of cement-treated base (CTB) mixtures containing high percentages of RAP.For this research, one …
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 …
Compositional And Structural Properties Of Emulsion-Treated Base Material: 7800 South In West Jordan, Utah, Lisa Renay Gurney
Compositional And Structural Properties Of Emulsion-Treated Base Material: 7800 South In West Jordan, Utah, Lisa Renay Gurney
Theses and Dissertations
The objectives of this research were 1) to examine correlations between compositional and structural properties of emulsion-treated base (ETB) layers, determine which of these factors exhibit the greatest spatial variability, and determine if significant differences exist between different test sections on a given project and 2) to investigate temporal trends in the structural properties of base materials treated with asphalt emulsion and to assess the rate at which ETB design properties are achieved. The research conducted in this study focused on testing of the ETB layer constructed on 7800 South (SR-48) in West Jordan, Utah. The research conducted in this …
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 …
Strength And Deformation Characteristics Of A Cement-Treated Reclaimed Pavement With A Chip Seal, Bryan T. Wilson
Strength And Deformation Characteristics Of A Cement-Treated Reclaimed Pavement With A Chip Seal, Bryan T. Wilson
Theses and Dissertations
The objective of this research was to analyze the strength and deformation characteristics of a cement-treated base (CTB) constructed using full-depth reclamation, microcracked, and then surfaced with a single chip seal. In this field study, strength characteristics of the CTB layer were determined at the time of construction, and then both strength and deformation characteristics were evaluated after 9 months of low-volume, heavy truck traffic. After 9 months, observed distresses included transverse cracking, rutting, and chip seal joint failure. The loss of the chip seal was caused by poor chip seal construction practices and not a deficiency in the CTB …
Temporal And Spatial Variability In Base Materials Treated With Asphalt Emulsion, Tyler James Quick
Temporal And Spatial Variability In Base Materials Treated With Asphalt Emulsion, Tyler James Quick
Theses and Dissertations
The first objective of this research was to investigate temporal trends in the mechanical properties of base materials stabilized with asphalt emulsion and to assess the rate at which emulsion-treated base (ETB) design properties are achieved. The second objective of this research was to identify construction and environmental factors most correlated to specific mechanical properties of ETB layers and to determine which construction factors exhibit the greatest variability. Additional statistical analysis was performed to determine if significant differences existed between different test sections on a given project. In this research, three experimental sections were established along a pavement reconstruction project …
Passive Earth Pressures On A Pile Cap With A Dense Sand Backfill, Robert Ashall Marsh
Passive Earth Pressures On A Pile Cap With A Dense Sand Backfill, Robert Ashall Marsh
Theses and Dissertations
Pile groups are often used to provide support for structures. Capping a pile group further adds to the system's resistance due to the passive earth pressure from surrounding backfill. While ultimate passive earth pressure under static loading conditions can be readily calculated using several different theories, the effects of cyclic and dynamic loading on the passive earth pressure response are less understood. Data derived from the full-scale testing of a pile cap system with a densely compacted sand backfill under static, cyclic, and dynamic loadings was analyzed with particular focus on soil pressures measured directly using pressure plates. Based on …
Behavior Of A Full-Scale Pile Cap With Loosely And Densely Compacted Clean Sand Backfill Under Cyclic And Dynamic Loadings, Colin Reuben Cummins
Behavior Of A Full-Scale Pile Cap With Loosely And Densely Compacted Clean Sand Backfill Under Cyclic And Dynamic Loadings, Colin Reuben Cummins
Theses and Dissertations
A series of lateral load tests were performed on a full-scale pile cap with three different backfill conditions, namely: with no backfill present, with densely compacted clean sand in place, and with loosely compacted clean sand in place. In addition to being displaced under a static loading, the pile cap was subjected to low frequency, small displacement loading cycles from load actuators and higher frequency, small displacement, dynamic loading cycles from an eccentric mass shaker. The passive earth pressure from the backfill was found to significantly increase the load capacity of the pile cap. At a displacement of about 46 …
Dynamic Full-Scale Testing Of A Pile Cap With Loose Silty Sand Backfill, Immanuel Kaleoonalani Runnels
Dynamic Full-Scale Testing Of A Pile Cap With Loose Silty Sand Backfill, Immanuel Kaleoonalani Runnels
Theses and Dissertations
Pile caps are used in foundation design to aid multiple single piles to act as a pile group to resist lateral forces that may cause overturning moments. The pile cap and pile group resist these forces by pile-soil-pile interaction, base and side friction along the pile cap-backfill interface, and passive earth resistance. Passive earth resistance has been neglected in design due to a limited amount of full-scale testing. This research presents the results of a combination of hydraulic actuator and eccentric-mass shaker full-scale testing of a pile cap with loose silty sand backfill to quantify the contribution of the passive …
Statnamic Lateral Loading Testing Of Full-Scale 15 And 9 Group Piles In Clay, Rick Davon Broderick
Statnamic Lateral Loading Testing Of Full-Scale 15 And 9 Group Piles In Clay, Rick Davon Broderick
Theses and Dissertations
Studies of seismic and impact loading on foundation piles is an important and a focused interest in the engineering world today. Because of seismic and other natural events are unpredictable, uncontrollable and potentially unsafe it is a vital study to understand the behavior and relationship structures in motion have on there foundation. Statnamic Loading has become a popular method of studying this relationship in a controlled environment. Two groups of 9 and 15 driven hollow pipe piles were tested in saturated clay at the Salt Lake City Airport in July of 2002. The 9-pile group (3x3 configuration) was separated at …
Characterization Of Recycled Concrete For Use As Pavement Base Material, Brandon J. Blankenagel
Characterization Of Recycled Concrete For Use As Pavement Base Material, Brandon J. Blankenagel
Theses and Dissertations
The use of recycled concrete material (RCM) as pavement base material is a promising but unproven technique for road rehabilitation and construction. A telephone survey conducted to investigate the state of the practice concerning RCM usage in Utah County revealed that RCM is infrequently used in this application due primarily to a lack of practical knowledge about the engineering properties of the material. Therefore, this research was aimed at evaluating the physical properties, strength parameters, and durability characteristics of both demolition and haul-back sources of RCM available in Utah County for use as pavement base material. The study included extensive …
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 …