Engineering Commons^™

Detector-Free Optimization Of Traffic Signal Offsets With Connected Vehicle Data, Cristopher Day, Howell Li, Lucy Richardson, James Howard, Tom Platte, Jim Sturdevant, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

It has recently been shown that signal offset optimization is feasible using vehicle trajectory data at low levels of market penetration. This study performs offset optimization on two corridors using this type ofdata. Six weeks oftrajectory splines were processed for two corridors including 25 signalized intersections, in order to create vehicle arrival profiles, using a proposed procedure called "virtual detection." After processing and filtering the data, penetration rates between 0.09-0.80% were observed, varying by approach. The arrival profiles were statistically compared against those measured with physical detectors, with the majority of the approaches showing statistically significant goodness-of-fit at a 90% …

Power-Weighted Divergences For Relative Attenuation And Delay Estimation, Ruairí De Fréin, Scott T. Rickard Prof

Articles

Power-weighted estimators have recently been proposed for relative attenuation and delay estimation in blind source separation. Their provenance lies in the observation that speech is approximately windowed-disjoint orthogonal (WDO) in the time-frequency (TF) domain; it has been reported that using WDO, derived from TF representations of speech, improves mixing parameter estimation. We show that power-weighted relative attenuation and delay estimators can be derived from a particular case of a weighted Bregman divergence. We then propose a wider class of estimators, which we tune to give better parameter estimates for speech.

Towards Concolic Testing For Hybrid Systems, Pingfan Kong, Yi Li, Xiaohong Chen, Jun Sun, Meng Sun, Jingyi Wang

Research Collection School Of Computing and Information Systems

Hybrid systems exhibit both continuous and discrete behavior. Analyzing hybrid systems is known to be hard. Inspired by the idea of concolic testing (of programs), we investigate whether we can combine random sampling and symbolic execution in order to effectively verify hybrid systems. We identify a sufficient condition under which such a combination is more effective than random sampling. Furthermore, we analyze different strategies of combining random sampling and symbolic execution and propose an algorithm which allows us to dynamically switch between them so as to reduce the overall cost. Our method has been implemented as a web-based checker named …

Reduced-Order Monte Carlo Modeling Of Radiation Transport In Random Media, Aaron J. Olson

Nuclear Engineering ETDs

The ability to perform radiation transport computations in stochastic media is essential for predictive capabilities in applications such as weather modeling, radiation shielding involving non-homogeneous materials, atmospheric radiation transport computations, and transport in plasma-air structures. Due to the random nature of such media, it is often not clear how to model or otherwise compute on many forms of stochastic media. Several approaches to evaluation of transport quantities for some stochastic media exist, though such approaches often either yield considerable error or are quite computationally expensive. We model stochastic media using the Karhunen-Loève (KL) expansion, seek to improve efficiency through use …

Industrial Cold-Formed Steel Rack Column Base Fixity And Strength, Francesc Roure, Teoman Peköz, M. Rosa Somalo, Jordi Bonada, M. Magdalena Pastor, Miquel Casafont, James Crews

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper summarizes the testing done at the Universitat Politècnica de Catalunya, Barcelona, Spain and the possible use of the results in design for column base stiffness and strength. The test setup and procedure are adopted in the European rack design standards.

Reduced Order Models For Profiled Steel Diaphragm Panels, G. Bian, S. Torabian, B. W. Schafer

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The objective of this paper is to provide progress on development and validation of reduced order models for the in plane strength and stiffness of profiled steel panels appropriate for use in structural models of an entire building. Profiled steel panels, i.e, metal deck, often serve as a key distribution element in building lateral force resisting systems. Acting largely as an in-plane shear diaphragm, metal deck as employed in walls, roofs, and floors plays a key role in creating and driving three-dimensional building response. As structural modeling evolves from two-dimensional frameworks to fully three-dimensional buildings, accurate and computationally efficient models …

Shear Resistance Of Cold-Formed Steel Framing Wall With X-Strap Bracing, Chi-Ling Pan, Chang-Chan Huang, Meng-Hsiu Tsao

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This research is concentrated on the study of structural strength and behavior of cold-formed steel frame with strap bracing subjected to horizontal loads. The wall specimens with and without calcium silicate board sheathing were tested to compare the differences of shear resistance. Based on the test data, the ultimate strength, stiffness, ductility ratio, and failure behavior were studied for each specimen, and the wall’s movements were also discussed in this paper. The cold-formed steel framing wall without bracing from previous study was introduced for the comparison purpose. As expected, the ultimate strength was increased for the cold-formed steel wall sheathed …

An Archetype Mid-Rise Building For Novel Complete Cold-Formed Steel Buildings, S. Torabian, Z. Saneei Nia, B. W. Schafer

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper introduces an archetype mid-rise cold-formed steel (CFS) building that aids in assessing the limits of current structural solutions, particularly lateral force resisting systems, and also in the development of new CFS technologies. A unified archetype building provides a platform for comparing the performance of new lateral force resisting systems to existing ones. The study herein provides quantitative evaluation of the design limitations of a typical “complete” cold-formed steel building (i.e. only cold-formed steel based elements are used for all gravity and lateral force resisting systems) at different heights (4 through 20 stories) located in a high seismic zone. …

Composite Metallic Nanofoam Structures, David Bahr, Matthew Howard, Mohamad Zbib, Raheleh Rahimi, John Balk

Composites at Lake Louise (CALL 2015)

Metallic nanofoams made of metals such as nickel (Ni) or gold (Au) with ligament sizes on the order of 10’s to 100’s of nm’s exhibit several remarkable properties as a consequence of their low relative density and high specific surface area, such as outstanding strength to weight ratios, enhanced plasmonic behavior and size-effect-enhanced catalytic behavior. However, these metallic nanofoams suffer from macroscopically brittle behavior due to plastic deformation in individual ligaments. With little or no barriers for slip, work-hardening is not possible within ligaments and extremely localized plasticity, once initiated, leads to a few ligaments necking and what appears to …

Characterization And Modeling To Design And Develop Tailored-Property Filled Glass Composites, Kevin Ewsuk

Composites at Lake Louise (CALL 2015)

Particle-filled-glass composites (FGCs) are being developed as new materials with structure and properties engineered for materials joining (e.g., for solid oxide fuel cells). Relative to conventional sealing glasses used to make hermetic glass-to-metal (GtM) seals, FGCs with tailored properties offer significant potential as more crack resistant hermetic seals with better performance and reliability. Additionally, compared to process sensitive crystallizable glasses, FGCs offer broader processing latitude and robustness, and afford greater control of seal microstructure and properties. FGCs are being developed using a combination of fundamental materials science and materials engineering, employing: 1) experimentally-validated molecular modeling to better understand and control …

Experimental Investigation Of The Effect Of Screw Fastener Spacing On The Local And Distortional Buckling Behavior Of Built-Up Cold-Formed Steel Columns, David C. Fratamico, Shahabeddin Torabian, Kim J. R. Rasmussen, Benjamin W. Schafer

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper addresses an ongoing experimental and computational effort on the buckling and strength of built-up cold-formed steel (CFS) columns. Specifically, two 6 in. (152 mm) deep lipped channel sections (i.e. the 600S137-54 and 600S162-54 using AISI S200-12 nomenclature) are studied here in a back-to-back, screw-connected form and were chosen for their local and distortional slenderness to study the effect of fastener spacing and layout on local and distortional buckling and collapse behavior. Thirty column tests are completed with concentric loading. The screw spacing is varied from L to L/6, where L is the column length, with and without varying …

An Improved Two-Stage Seismic Analysis Procedure For Mid-Rise Buildings With Vertical Combination Of Cold-Formed Steel And Concrete Framing, X. Yuan, L. Xu

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Presented in this paper is an improved two-stage analysis procedure for evaluating the seismic load of the mid-rise buildings with vertical combination of cold-formed steel and concrete framing. By comparing the improved procedure to the one prescribed in ASCE 7, it is found the stiffness requirement of the two-stage analysis procedure stated in ASCE 7 may be over-relaxed, which may consequently result in the underestimation of the base shear of the upper structure in certain cases. Furthermore, the lateral load at the top storey of the upper structure evaluated by ASCE 7 two-stage analysis procedure may also be considerably underestimated. …

Characterizing The Load Deformation Behaviour Of Steel Deck Diaphragms, P. O'Brien, S. Florig, C. D. Moen, M. R. Eatherton

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Lateral loads flow through a building’s horizontal roof and floor diaphragms before being transferred to the vertical lateral force resisting system (e.g. braced frames, moment frames or shear walls). These diaphragms are therefore a critical structural component in the resistance of lateral loads. A review of the literature shows that a large number of experimental programs have been performed to obtain the in-plane load-deformation behavior of steel deck and concrete on steel deck diaphragms. The tested diaphragm behavior was found to be dependent on a set of factors including loading protocol, fastener type, fastener size and spacing, and more. There …

Experiments On Column Base Stiffness Of Long-Span Cold-Formed Steel Portal Frames Composed Of Double Channels, H. B. Blum, K. J. R. Rasmussen

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Cold-formed steel haunched portal frames are popular structures in industrial and housing applications. They are mostly used as sheds, garages, and shelters, and are common in rural areas. Cold-formed steel portal frames with spans of up to 30m (100 ft) are now being constructed in Australia. As these large structures are fairly new to the market, there is limited data on their feasibility and design recommendations. An experimental program was carried out on a series of portal frame systems composed of back-to-back channels for the columns, rafters, and knee braces. The system consisted of three frames connected in parallel with …

Application Of The Direct Strength Method To Steel Deck, Randall Keith Dudenbostel, Thomas Sputo

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

With the reorganization of the AISI S100 Standard, the Direct Strength Method (DSM) takes a position of equal footing with the Equivalent Width Method (EWM) for calculating the strength of cold-formed steel cross sections. The majority of previous DSM studies focused on C and Z profiles, while little study of panel sections, especially steel deck sections, has been performed. A study was undertaken to determine and compare the behavior and usable strength of existing floor and roof deck sections with both DSM and EWM. The Cornell University – Finite Strip Method (CUFSM) software was used for the elastic buckling analysis, …

Advanced Modeling Of Cold-Formed Steel Walls Under Fire, J. C. Batista Abreu, N. Punati, K. R. Prasad, B. W. Schafer

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper discusses an advanced finite element model able to simulate the structural response of cold-formed steel walls during standard fire tests. The model includes experimental thermo-mechanical properties of materials, geometric imperfections, and temperature distributions on studs and sheathing boards. The model is capable of reasonably predicting the thermal bowing of walls, and estimating the shape, size and amount of joint openings between gypsum boards over time of fire exposure. Numerical results validated with experimental data indicate that the maximum out-of-plane displacements due to thermal gradients occur near the wall mid-height. Early in the heating process, joint openings develop on …

Development Of A Method To Generate A Simplified Finite Element Model For An Electrical Switchboard Cabinet, Edwin Lim, Barry J. Goodno, James I. Craig

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Electrical switchboards are one of the key pieces of equipment used in operations of most critical facilities such as hospitals and emergency services buildings. Unfortunately, past observations have shown that the switchboard cabinet and its contents may be vulnerable to damage or failure during an earthquake. An electrical switchboard cabinet is a complex structure typically constructed using cold-formed steel frame members enclosed by steel panels and containing a variety of switchgear and bus bars. The panels are usually fastened to the steel members by screws, and the steel members are connected together by bolts or screws. The structural behavior of …

Full-Scale Experimental And Numerical Study About Structural Behavior Of Thin-Walled Cold-Formed Steel Building Affected By Ground Settlements Due To Land Subsidence, Jose A. Ortiz-Lozano, Luis A. Hernández-Castillo, Martin Hernández-Marín, Jesús Pacheco-Martínez, Mario E. Zermeño-Deleón, Raúl Salinas-Salinas

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Land subsidence phenomenon due to ground water withdrawal is a current problem in many places around the world, particularly in the shallows of Mexico. This causes ground differential settlements that affect structures, mainly dwellings and buildings based on reinforced concrete and masonry. Eventually, these structural materials do not exhibit an adequate performance beyond a certain level of angular distortion. This work presents the experimental and numerical results about a study regarding the performance of a full-scale thin-walled cold-formed steel building affected by angular distortions simulating ground differential settlements due to land subsidence. The experimental stage consisted in the design and …

Design Method For Cold-Formed Thin-Walled Steel Beams With Built-Up Box Section, Ying-Lei Li, Yuan-Qi Li

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Built-up sections has been extensively used in cold-formed thin-walled steel structures. The structural behaviour and moment capacity of built-up box beams, which is consisted of nested C and U-sections, are the major concerns in this paper. A finite element model for built-up box beams was firstly developed and validated by existing test results. The effects of screw configuration and the global buckling behaviour of built-up box beams were investigated by parametric analysis. Then, the simple superposition method and equivalent cross-section method were introduced and adopted to estimate the moment capacity of built-up box beams bending about major or minor axis. …

Design Of Industrial Cold-Formed Steel Rack Upright Frames For Loads In Cross-Aisle Direction, Francesc Roure, Teoman Peköz, M. Rosa Somalo, Jordi Bonada, M. Magdalena Pastor, Miquel Casafont

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper summarizes research on the cross-aisle stiffness and strength of industrial cold-formed steel rack upright frames for loads in cross-aisle direction. Tests were carried out at the Universitat Politècnica de Catalunya, Barcelona, Spain on joints as well as entire upright frames. A possible rather simple analysis procedure is developed and described.

Site Response Analysis Considering Strain Compatible Site Period, Hoss Hayati, Robb E.S. Moss

Civil and Environmental Engineering

In practice it is common to estimate site effects using a single proxy, or single variable such as 30 m shear wave velocity (V_S30) or site period. Many studies have investigated merits of proposed proxies with contradicting recommendations. Yet, most studies indicate the single proxy approach is less than ideal, resulting in large uncertainty. To provide a better understanding of components that drive site response, we performed a parameterized study on 19 shallow soil profiles with V_S ranging from 150 m/s to 400 m/s. We propagated 74 input motions through each soil column using one-dimensional equivalent-linear …

Site Response Analysis Considering Strain Compatible Site Period, Hoss Hayati, Robb E.S. Moss

Civil and Environmental Engineering

In practice it is common to estimate site effects using a single proxy, or single variable such as 30 m shear wave velocity (V_S30) or site period. Many studies have investigated merits of proposed proxies with contradicting recommendations. Yet, most studies indicate the single proxy approach is less than ideal, resulting in large uncertainty. To provide a better understanding of components that drive site response, we performed a parameterized study on 19 shallow soil profiles with V_S ranging from 150 m/s to 400 m/s. We propagated 74 input motions through each soil column using one-dimensional equivalent-linear …

Wells Fargo, Samsung And Spacex: The Dos And Don’Ts Of Today’S Quality Environment, Jim Burgin

Operations Management Presentations

Quality is everywhere, and is so critical to your success. This webinar will use Toyota’s 14 Principles as the springboard to discuss teach points from my Quality Management class. The title mentions a few companies where good practices or challenging activities provide a road map to success or failure. Rest assured there are many more. Burgin uses stories and experiences from class to illustrate quality concepts.

Aircraft Decelerating And Stopping Systems, Nihad E. Daidzic

Aviation Department Publications

FAA Safety Seminar (GL1572070) held at Minnesota State University, Mankato Wiecking Center Auditorium at 18:30 CST on Thursday, November 10, 2016.

The Effects Of Compensatory Auditory Stimulation And High-Definition Transcranial Direct Current Stimulation (Hd-Tdcs) On Tinnitus Perception - A Randomized Pilot Study, Simon Henin, Dovid Fein, Eric Smouha, Lucas C. Parra

Publications and Research

Background Tinnitus correlates with elevated hearing thresholds and reduced cochlear compression. We hypothesized that reduced peripheral input leads to elevated neuronal gain resulting in the perception of a phantom sound. Objective The purpose of this pilot study was to test whether compensating for this peripheral deficit could reduce the tinnitus percept acutely using customized auditory stimulation. To further enhance the effects of auditory stimulation, this intervention was paired with high-definition transcranial direct current stimulation (HD-tDCS).

Methods A randomized sham-controlled, single blind study was conducted in a clinical setting on adult participants with chronic tinnitus (n = 14). Compensatory auditory stimulation …

Ocean–Atmosphere Interactions Modulate Irrigation’S Climate Impacts, Nir Y. Krakauer, Michael J. Puma, Benjamin I. Cook, Pierre Gentine, Larisa Nazarenko

Publications and Research

Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean– atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity.We find that ocean–atmosphere interaction does impact the magnitude of globalmean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, …

Characterization Of Cold-Formed Steel Framed Diaphragm Response Under In-Plane Loading And Influence Of Non-Structural Gypsum Panels, Patrick Latreille, Violetta Nikolaidou, Colin A. Rogers, Dimitrios G. Lignos

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The in-plane response of CFS framed diaphragm structures subjected to seismic excitation is not well understood. At present, the North American AISI S400 Standard does not include a seismic design procedure for CFS framed diaphragms for use in Canada, and offers limited information for their use in the US. In addition, the effect of non-structural components on the lateral strength and stiffness of the diaphragm component has yet to be explored. In an effort to provide insight into the complex nature of the diaphragm structure and the influence of non- structural components an experimental program was initiated in the Jamieson …

Resistance Of Arc Spot Welds – Update To Provisions, B. Paige Blackburn, Thomas Sputo

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The AISI S100-12 provisions for arc spot welds have not be reviewed since 1999. This study performs a comprehensive analysis of the entire arc spot weld data base including data from four new research studies and reconsiders AISI S100-12 resistance equations with data from 450 specimens. Most AISI S100-12 equations were found to be conservative, particularly for sheet tearing failure modes. However, the equation for arc spot weld fracture under tensile load was found to poorly predict the data base test results. AISI S100-12 provision improvements are recommended not only for the resistance equations and factors, but also for the …

Finite Element Modeling Of Concrete Shrinkage In Composite Deck Slabs, Vitaliy V. Degtyarev

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper presents finite element models of composite deck slabs subjected to restrained concrete shrinkage. The models created in ANSYS and validated against test data were based on the assumption of the full shear interaction between the deck and the concrete and accounted for concrete creep, cracking, and nonlinear stress-strain relationship. Concrete shrinkage was modeled by temperature changes applied to concrete. The effects of different shrinkage profiles, concrete creep, and deck slab properties on the long-term concrete and deck strains are presented. Future research work is outlined.

A Combined Direct Analysis And Direct Strength Approach To Predict The Flexural Strength Of Z-Purlins With Paired Torsion Braces, Michael W. Seek, Chris Ramseyer, Ian Kaplan

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A series of 12 Base Tests for Z-section purlins with paired interior torsional braces and one flange attached to a flexible horizontal diaphragm are evaluated with the Direct Strength Method. Rather than use the conventional constrained bending stress approximation, a direct analysis philosophy is adopted where cross section stress distributions are calculated using a displacement compatibility approach. With a flexible diaphragm typical of a standing seam roof system, these stresses can deviate substantially from the constrained bending approximation and can significantly impact predicted local and distortional buckling behavior. The displacement compatibility approach incorporates estimates of load imbalances and second order …