Engineering Commons^™

An Analytical Model Of A Thermally Excited Microcantilever Vibrating Laterally In A Viscous Fluid, Stephen M. Heinrich, Rabin Maharjan, Isabelle Dufour, Fabien Josse, Luke A. Beardslee, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

To achieve higher quality factors (Q) for microcantilevers used in liquid-phase sensing applications, recent studies have explored the use of the lateral (in-plane) flexural mode. In particular, we have recently shown that this mode may be excited electrothermally using integrated heating resistors near the micro cantilever support, and that the resulting increase in Q helps to make low-ppb limits of detection a possibility in liquids. However, because the use of electrothermally excited, liquid-phase, microcantilever-based sensors in lateral flexure is relatively new, theoretical models are lacking. Therefore, we present here a new analytical model for predicting the vibratory response of these …

Geometrical Optimization Of Resonant Cantilevers Vibrating In In-Plane Bending Modes, Luke A. Beardslee, Assim M. Addous, Kemal S. Demirci, Oliver Brand, Stephen M. Heinrich, Fabien Josse

Civil and Environmental Engineering Faculty Research and Publications

The influence of the beam geometry on the quality factor and resonance frequency of resonant silicon cantilever beams vibrating in their fundamental in-plane flexural mode has been investigated in air and water. Compared to cantilevers vibrating in their out-of-plane flexural mode, utilizing the in plane mode results in reduced damping and reduced mass loading by the surrounding fluid. Quality factors as high as 4,300 in air and 67 in water have been measured for cantilevers with a 12 μm thick silicon layer. This is in comparison to Q factors up to 1,500 in air and up to 20 in water …

Risk-Based Seismic Design Optimization Of Steel Building Systems With Passive Damping Devices, Junshan Liu

Dissertations (1934 -)

Nonlinear time history analysis software and an optimization algorithm for automating design of steel frame buildings with and without supplemental passive damping systems using the risk- or performance-based seismic design philosophy are developed in this dissertation. The software package developed is suitable for conducting dynamic analysis of 2D steel framed structures modeled as shear buildings with linear/nonlinear viscous and viscoelastic dampers. Both single degree of freedom (SDOF) and multiple degree of freedom (multistory or MDOF) shear-building systems are considered to validate the nonlinear analysis engine developed. The response of both un-damped and damped structures using the 1940 EI Centro (Imperial …

Evaluation Of Runoff Response To Moving Rainstorms, Jin Liang

Dissertations (1934 -)

The primary hypothesis from the hydrological literature is that downstream moving storms with storm length (Ls) less than watershed length (Lc) magnify the peak discharges. This hypothesis was developed from the kinematic-wave modeling, and was evaluated in a plot between the dimensionless peak discharge and dimensionless storm velocity. Previously unpublished experimental data collected from the Watershed Experimentation System (WES), obtained from the late Professor Ben C. Yen at the University of Illinois at Urbana-Champaign, were used in comparison with the simulation results of the kinematic-wave model. It is found that downstream moving storms with Ls/Lc <1 increase the peak discharges to a limited extent compared to stationary storms, but the kinematic-wave model overstates the increase in the peak flows resulting from downstream moving storms with Ls/Lc <1. This difference between model projections and laboratory data was attributed to backwater effects in the experimental runoff.

To evaluate the importance of …

Bioaugmentation For Recovery Of Anaerobic Digesters Subjected To Organic Overload, Vaibhav Panjabrao Tale

Dissertations (1934 -)

Anaerobic digester upset due to organic overload is common and methods to reduce recovery time would be beneficial. One potential method is bioaugmentation, the addition of an external culture for performance improvement. Methanogenic community structure differs from digester to digester and there may exist a relation between specific methanogenic activity (SMA) and microbial community composition. The research presented herein tested whether there is a relationship between SMA and community structure. Also, the effectiveness of bioaugmentation was tested by hypothesizing that bioaugmenting with a methanogenic, propionate-degrading culture acclimated to small oxygen doses will help rapid recovery of organically overloaded digesters.

Fourteen …

Performance Evaluation Of Open Graded Base Course With Doweled And Non-Doweled Transverse Joints, Robert Schmitt, Samuel Owusu-Ababio, James Crovetti

Transportation Reports with the Wisconsin Department of Transportation

The objectives of this study were to investigate the performance of 20-year old doweled/non-doweled and dense-graded/permeable base test sections on three concrete pavement segments in Wisconsin: USH 18/151 in Iowa and Dane counties, STH 29 in Brown County, and USH 151 in Columbia and Dane Counties. Five pavement bases were placed including: dense graded, asphalt-stabilized permeable, cement-stabilized permeable, and untreated permeable having two gradation sizes.

USH 18/151 test sections had similar performance (PDI) for doweled unsealed pavement on dense and permeable base. Distresses common to all segments included slight to moderate distressed joints/cracks and slight transverse faulting. Asphalt-stabilized permeable base …

Liquid-Phase Chemical Sensing Using Lateral Mode Resonant Cantilevers, Luke A. Beardslee, Kemal S. Demirci, Y. Luzinova, B. Mizaikoff, Stephen M. Heinrich, Fabien Josse, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Liquid-phase operation of resonant cantilevers vibrating in an out-of-plane flexural mode has to date been limited by the considerable fluid damping and the resulting low quality factors (Q factors). To reduce fluid damping in liquids and to improve the detection limit for liquid-phase sensing applications, resonant cantilever transducers vibrating in their in-plane rather than their out-of-plane flexural resonant mode have been fabricated and shown to have Q factors up to 67 in water (up to 4300 in air). In the present work, resonant cantilevers, thermally excited in an in-plane flexural mode, are investigated and applied as sensors for volatile …

Passenger Car Equivalent Factors For Level Freeway Segments Operating Under Moderate And Congested Conditions, Umama Ahmed

Master's Theses (2009 -)

The significant impact Heavy Vehicles (HV) have on freeway operations has been identified since the first edition of the Highway Capacity Manual (HCM). The method of incorporating their impact in freeway capacity calculations has changed through the years. The HCM 2000 used Passenger Car Equivalent (PCE) values and percent of trucks/buses and Recreational Vehicles (RV) to account for HV effect on capacity. However PCE values in the most recent HCM edition rely on a limited field database and extensive simulation runs based on this information; they were calibrated on `steady-flow' traffic operations. The objective of this effort was to indentify …

Thermal Excitation And Piezoresistive Detection Of Cantilever In-Plane Resonance Modes For Sensing Applications, Luke A. Beardslee, Assim M. Addous, Stephen M. Heinrich, Fabien Josse, Isabelle Dufour, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Thermally excited and piezoresistively detected bulk-micromachined cantilevers vibrating in their in-plane flexural resonance mode are presented. By shearing the surrounding fluid rather than exerting normal stress on it, the in-plane mode cantilevers exhibit reduced added fluid mass effects and improved quality factors in a fluid environment. In this letter, different cantilever geometries with in-plane resonance frequencies from 50 kHz to 2.2 MHz have been tested, with quality factors as high as 4200 in air and 67 in water.

In-Situ Monitoring And Testing Of Ibrc Bridges In Wisconsin, Christopher Foley, Baolin Wan, Carl Schneeman, Kristine Barnes, Jordan Komp, Junshan Liu, Andrew Smith

Transportation Reports with the Wisconsin Department of Transportation

This study examines two highway bridges constructed using novel fiber-reinforced polymer (FRP) composite stay-in-place formwork and an FRP grillage reinforcement system. Both bridge superstructures rely on the FRP components as bridge deck reinforcement. These bridges were monitored in-situ for a period of five years. The monitoring included a series of in-situ load test as well as non-destructive evaluation (NDE). Laboratory investigations accompanied and guided the load testing and NDE implemented. Finite element simulations were employed to evaluate the likely causes of premature deck cracking seen in the traditionally-constructed bridge and the FRP-component superstructures. The study identifies sources of potential deterioration, …

Resonant Microcantilevers Vibrating Laterally In Viscous Liquid Media, Russell Cox, Fabien Josse, Stephen M. Heinrich, Isabelle Dufour, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

The characteristics of microcantilevers vibrating in the in-plane flexural mode (also known as lateral vibration) in viscous liquid media are investigated. A numerical model was utilized to determine a correction to Stokes' solution for an infinite plate to obtain an analytical expression for the hydrodynamic forces acting on a laterally vibrating microcantilever as a function of both Reynolds number and aspect ratio (thickness over width). The results allowed for the resonant frequency and quality factor to be investigated as a function of both beam geometry and medium properties. Trends in these characteristics can be used to optimize device geometry and …

Simulation Of Scenarios To Meet Dissolved Oxygen Standards In The Chicago Waterway System, Yaping Ao

Master's Theses (2009 -)

Although most reaches of the Chicago Waterway System (CWS) meet the General Use Water Quality Standards a high percentage of the time, dissolved oxygen (DO) standards are not met in the CWS during some periods for both the WYs 2001 and 2003 as representative of wet and dry years. Several methods were used to solve this problem; however, they were inadequate for achieving the proposed DO standards. Therefore, a method of integrating the alternative DO remediation methods into one integrated strategy for improving water quality is considered in this study.

The main purpose of this study is the application of …

Perpetual Pavement Analysis For The Marquette Interchange Instrumentation Project, Nicholas James Hornyak

Dissertations (1934 -)

With the emergence of the mechanistic-empirical pavement design process, development of pavements rely on the structural response and fatigue characteristics of pavement materials due to traffic loads. In the past, pavement design has been almost entirely based on empirical data. One area of interest in designing hot-mix asphalt (HMA) pavements is the fatigue life of the pavement, which has been shown to be dependent on the horizontal strain in the pavement.

This research is focused on measuring the structural response of a pavement located within the Marquette Interchange Project in order to analyze fatigue behavior with great detail. Virtually all …

Real-Time Health Monitoring System For Mast-Arm Sign Support Structures, Andrew David Smith

Master's Theses (2009 -)

There has been an ongoing study conducted by Marquette University and supported by the Wisconsin Highway Research Program that is seeking to understand the risk of fatigue-induced fracture in the connections of mast-arm sign support structures. This study has been brought on by recent problems encountered with the connections contained in, and the in-service performance of, several cantilevered mast-arm sign support structures. A resulting recommendation of phase one in this effort was to monitoring an in-service cantilevered mast-arm sign support structure.

The health monitoring system developed in this thesis effort includes a grouping of strain gages (full-bridge arrangements) positioned around …

A Visual Approach To Construction Cost Estimating, Phuwadol Samphaongoen

Master's Theses (2009 -)

Construction cost estimating is considered one of the most important and critical phases of a construction project. Preparing reliable and accurate estimates to help decision makers is the most challenging assignment that estimators face. An estimate is not only necessary for proposal preparation but also for several project management functions. Despite the importance of estimating, it has remained a very time consuming process. The most inefficient part of construction cost estimating is determination of the amount of resources needed for the construction of a project. This is also known as quantity takeoff. Quantity takeoff is a very long and error-prone …

Concrete Cracking In New Bridge Decks And Overlays, Baolin Wan, Christopher Foley, Jordan Komp

Transportation Reports with the Wisconsin Department of Transportation

There appears to be a trend for new bridge decks in the state of Wisconsin to develop early-age transverse cracks and map cracks on concrete overlays. A comprehensive literature review of the potential causes of concrete bridge deck cracking is provided. Fifteen bridge structures found in the recently completed Marquette Interchange were analyzed using 21 variables thought to cause early-age bridge deck cracking. Visual inspection of sixteen bridges in Milwaukee is described. The inspections show that the continuous superstructures have more cracks than the simply-supported bridges. A finite element model was created for a typical two-span continuous superstructure with HL-93 …

Analyzing Motorists’ Responses To Temporary Signage In Highway Work Zones, Yong Bai, Kris Finger, Yue Li

Civil and Environmental Engineering Faculty Research and Publications

For decades, the importance of highway work zone safety has increased considerably with the continual increase in the number of highway work zones present on highways for repairs and expansion. Rural work zones on two-lane highways are particularly hazardous and cause a significant safety concern due to the disruption of regular traffic flow. In this study, researchers determined motorists’ responses to warning signs in rural, two-lane highway work zones. The researchers divided vehicles into three classes (passenger car, truck, and semitrailer) and compared the mean change in speed of these classes based on three different sign setups: portable changeable message …

Unconventional Uses Of Cantilevers For Chemical Sensing In Gas And Liquid Environments, Isabelle Dufour, Fabien Josse, Stephen M. Heinrich, C. Lucat, C. Ayela, F. Ménil, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Microcantilevers used as (bio)chemical sensors are usually coated with a chemically sensitive layer. The coated devices operate either in a static bending regime or in a dynamic flexural mode. While the coated devices operate generally well in both the static and dynamic mode, they do suffer from certain shortcomings depending on the medium of operation and the application, including lack of selectivity and of reversibility of the sensitive coating and a reduced quality factor due to the surrounding medium. In particular, the performance of microcantilevers excited in their standard out-of-plane dynamic mode drastically decreases in viscous liquid media. Moreover, the …

Tapping Environmental History To Recreate America’S Colonial Hydrology, Christopher L. Pastore, Mark B. Green, Daniel J. Bain, Andrea Muñoz-Hernandez, Charles J. Vörösmarty, Jennifer Arrigo, Sara Brandt, Jonathan M. Duncan, Francesca Greco, Hyojin Kim, Sanjiv Kumar, Michael Lally, Anthony J. Parolari, Brian Pellerin, Nira Salant, Adam Schlosser, Kate Zalzal

Civil and Environmental Engineering Faculty Research and Publications

To properly remediate, improve, or predict how hydrological systems behave, it is vital to establish their histories. However, modern-style records, assembled from instrumental data and remote sensing platforms, hardly exist back more than a few decades. As centuries of data is preferable given multidecadal fluxes of both meteorology/climatology and demographics, building such a history requires resources traditionally considered only useful in the social sciences and humanities. In this Feature, Pastore et al. discuss how they have undertaken the synthesis of historical records and modern techniques to understand the hydrology of the Northeastern U.S. from Colonial times to modern day. Such …