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Articles 1 - 13 of 13

Full-Text Articles in Mechanical Engineering

The Quasi-Static Deformation, Failure, And Fracture Behavior Of Titanium Alloy Gusset Plates Containing Bolt Holes, Therese Hurtuk, Craig Menzemer, Anil Patnaik, Tirumalai Srivatsan, Kannan Manigandan, T. Quick Oct 2015

The Quasi-Static Deformation, Failure, And Fracture Behavior Of Titanium Alloy Gusset Plates Containing Bolt Holes, Therese Hurtuk, Craig Menzemer, Anil Patnaik, Tirumalai Srivatsan, Kannan Manigandan, T. Quick

Craig Menzemer

In this article, the influence of bolt holes, specifically their number and layout on strength, deformation, and final fracture behavior of titanium alloy gusset plates under the influence of an external load is presented and discussed. Several plates having differences in both the number and layout of the bolt holes were precision machined and then deformed under quasi-static loading. The specific influence of number of bolt holes and their layout on maximum load-carrying capability and even fracture load was determined. The conjoint influence of bolt number, bolt layout pattern, nature of loading, contribution from local stress concentration, and intrinsic microstructural …


The Quasi-Static Deformation, Failure, And Fracture Behavior Of Titanium Alloy Gusset Plates Containing Bolt Holes, Therese Hurtuk, Craig Menzemer, Anil Patnaik, Tirumalai Srivatsan, Kannan Manigandan, T. Quick Aug 2015

The Quasi-Static Deformation, Failure, And Fracture Behavior Of Titanium Alloy Gusset Plates Containing Bolt Holes, Therese Hurtuk, Craig Menzemer, Anil Patnaik, Tirumalai Srivatsan, Kannan Manigandan, T. Quick

Anil Patnaik

In this article, the influence of bolt holes, specifically their number and layout on strength, deformation, and final fracture behavior of titanium alloy gusset plates under the influence of an external load is presented and discussed. Several plates having differences in both the number and layout of the bolt holes were precision machined and then deformed under quasi-static loading. The specific influence of number of bolt holes and their layout on maximum load-carrying capability and even fracture load was determined. The conjoint influence of bolt number, bolt layout pattern, nature of loading, contribution from local stress concentration, and intrinsic microstructural …


Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta Aug 2015

Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta

Joan Carletta

We demonstrate a high throughput, all-electronic Coulter-type sensor with four sensing microapertures to detect and count micro-scale particles. Four particle samples are utilized for this study: polymethacrylate particles 40 µm and 20 µm in diameter, Juniper Scopulorum (Rocky Mountain Juniper) pollen and Cottonwood pollen particles. The two types of pollen particles are roughly 20 µm in diameter. The particles are mixed with deionized water and forced to pass through the microapertures. Voltage pulses across all four apertures are recorded and analysed. Results demonstrate that the sensor can detect and count particles through its four sensing apertures simultaneously. Thus, the counting …


Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta Apr 2015

Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta

Dr. Jiang Zhe

We demonstrate a high throughput, all-electronic Coulter-type sensor with four sensing microapertures to detect and count micro-scale particles. Four particle samples are utilized for this study: polymethacrylate particles 40 µm and 20 µm in diameter, Juniper Scopulorum (Rocky Mountain Juniper) pollen and Cottonwood pollen particles. The two types of pollen particles are roughly 20 µm in diameter. The particles are mixed with deionized water and forced to pass through the microapertures. Voltage pulses across all four apertures are recorded and analysed. Results demonstrate that the sensor can detect and count particles through its four sensing apertures simultaneously. Thus, the counting …


Analytical Models For Atomic Friction, Yalin Dong, Ajay Vadakkepatt, Ashlie Martini Apr 2015

Analytical Models For Atomic Friction, Yalin Dong, Ajay Vadakkepatt, Ashlie Martini

Dr. Yalin Dong

In this methods article, we describe application of Prandtl–Tomlinson models and their extensions to interpret dry atomic-scale friction. The goal is to provide a practical overview of how to use these models to study frictional phenomena. We begin with the fundamental equations and build on them step-by-step—from the simple quasistatic one-spring, one-mass model for predicting transitions between friction regimes to the two-dimensional and multi-atom models for describing the effect of contact area. The intention is to bridge the gap between theoretical analysis, numerical implementation, and predicted physical phenomena. In the process, we provide an introductory manual with example computer programs …


Zwitteration Of Dextran: A Facile Route To Integrate Antifouling, Switchability And Optical Transparency Into Natural Polymers, Bin Cao, Linlin Li, Haiyan Wu, Qiong Tang, Bingbing Sun, He Dong, Jiang Zhe, Gang Cheng Apr 2015

Zwitteration Of Dextran: A Facile Route To Integrate Antifouling, Switchability And Optical Transparency Into Natural Polymers, Bin Cao, Linlin Li, Haiyan Wu, Qiong Tang, Bingbing Sun, He Dong, Jiang Zhe, Gang Cheng

Dr. Jiang Zhe

This communication reports a facile method for zwitteration of dextran with carboxybetaine (CB), which integrates superior antifouling properties, switchability between zwitterionic and cationic forms, as well as enhanced optical transparency into one polysaccharide material. This study provides a new avenue for generating multifunctional zwitterionic CB materials in situ.


Optical Cell For Combinatorial In Situ Raman Spectroscopic Measurements Of Hydrogen Storage Materials At High Pressures And Temperatures, Jason Hattrick-Simpers, Wilbur Hurst, Sesha Srinivasan, James Maslar Mar 2015

Optical Cell For Combinatorial In Situ Raman Spectroscopic Measurements Of Hydrogen Storage Materials At High Pressures And Temperatures, Jason Hattrick-Simpers, Wilbur Hurst, Sesha Srinivasan, James Maslar

Jason R. Hattrick-Simpers

An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storagematerials at pressures up to 10 MPa and temperatures up to 823 K. High throughput is obtained by employing a 60 mm diameter × 9 mm thick sapphire window, with a corresponding 50 mm diameter unobstructed optical aperture. To reproducibly seal this relatively large window to the cell body at elevated temperatures and pressures, a gold o-ring is employed. The sample holder-to-window distance is adjustable, making this cell design compatible with optical measurement systems incorporating lenses of significantly different focal lengths, e.g., microscope objectives and single element …


Development Of A New Lagrangian Float For Studying Coastal Marine Ecosystems, Alex Schwithal, Chris Roman Jan 2013

Development Of A New Lagrangian Float For Studying Coastal Marine Ecosystems, Alex Schwithal, Chris Roman

Christopher N. Roman

This paper presents an overview and initial testing results for a shallow water Lagrangian float designed to operate in coastal settings. The presented effort addresses the two main characteristics of the shallow coastal environment that preclude the direct of use of many successfully deep water floats, namely the higher variation of water densities near the coast compared with the open ocean and the highly varied bathymetry. Our idea is to develop a high capacity dynamic auto-ballasting system that is able to compensate for the expected seawater density variation over a broad range of water temperatures and salinities while using measurements …


Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert Dec 2012

Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert

Christopher N. Roman

Efficiently profiling the water column to achieve both high vertical and horizontal resolution from a moving vessel in deep water is difficult. Current solutions, such as CTD tow-yos, moving vessel profilers, and undulating tow bodies, are limited by ship speed or water depth. As a consequence, it is difficult to obtain oceanographic sections with sufficient resolution to identify many relevant scales over the deeper sections of the water column. This paper presents a new concept for a profiling vehicle that slides up and down a towed wire in a controlled manner using the lift created by wing foils. The wings …


Trajectory Generation In High-Speed, High-Precision Micromilling Using Subdivision Surfaces, Athulan Vijayaraghavan, Angela Sodemann, Aaron Hoover, J. Mayor, David Dornfeld Jul 2012

Trajectory Generation In High-Speed, High-Precision Micromilling Using Subdivision Surfaces, Athulan Vijayaraghavan, Angela Sodemann, Aaron Hoover, J. Mayor, David Dornfeld

Aaron M. Hoover

Motion control in high-speed micromilling processes requires fast, accurate following of a specified curvilinear path. The accuracy with which the path can be followed is determined by the speed at which individual trajectories can be generated and sent to the control system. The time required to generate the trajectory is dependent on the representations used for the curvilinear trajectory path. In this study, we introduce the use of subdivision curves as a method for generating high-speed micromilling trajectories. Subdivision curves are discretized curves which are specified as a series of recursive refinements of a coarse mesh. By applying these recursive …


Precis: A Usercentric Word-Length Optimization Tool, Mark Chang, Scott Hauck Jul 2012

Precis: A Usercentric Word-Length Optimization Tool, Mark Chang, Scott Hauck

Mark L. Chang

Translating an algorithm designed for a general-purpose processor into an algorithm optimized for custom logic requires extensive knowledge of the algorithm and the target hardware. Precis lets designers analyze the precision requirements of algorithms specified in Matlab. The design time tool combines simulation, user input, and program analysis to help designers focus their manual precision optimization efforts.


Bistability In A Simple Fluid Network Due To Viscosity Contrast, John Geddes, Brian Storey, David Gardner, Russell Carr Mar 2012

Bistability In A Simple Fluid Network Due To Viscosity Contrast, John Geddes, Brian Storey, David Gardner, Russell Carr

Brian Storey

We study the existence of multiple equilibrium states in a simple fluid network using Newtonian fluids and laminar flow. We demonstrate theoretically the presence of hysteresis and bistability, and we confirm these predictions in an experiment using two miscible fluids of different viscosity—sucrose solution and water. Possible applications include blood flow, microfluidics, and other network flows governed by similar principles.


Control System Performance And Efficiency For A Mid-Depth Lagrangian Profiling Float, B. Mcgilvray, C. Roman May 2010

Control System Performance And Efficiency For A Mid-Depth Lagrangian Profiling Float, B. Mcgilvray, C. Roman

Christopher N. Roman

This paper presents the development of a new mid-depth Lagrangian profiling float with a primary emphasis on the control system performance and efficiency. While deep water floats have demonstrated much success in open ocean environments, many are not suited for the additional challenges associated with coastal regions. To study these regions, which are often subject to varying bathymetry within the operating range and higher variations in water density, a more advanced system is required. This new design utilizes pressure and altitude feedback to drive a high volume auto-ballasting system (ABS). The main operating modes of this float include step inputs …