Engineering Commons^™

Simulating The Seismic Performance Of Cold-Formed Steel Framed Buildings Using Corrugated Sheet Shear Walls, Wenying Zhang, Mahsa Mahdavian, Yuanqi Li, Cheng Yu

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

Cold-formed steel framed shear wall sheathed with corrugated steel sheets is a promising shear wall system for low- and mid-rise constructions at high wind and seismic zones due to its advantages of non-combustibility, high shear strength, and high shear stiffness. A lot of work has been done on this subject. However, all the previous work is focused on the wall panel levels and more research work is needed on the entire building systems. The objective of this paper is to investigate the response of a cold-formed steel framed building with corrugated sheet sheathing subjected to earthquake excitation primarily through nonlinear …

Behavior Of Steel Sheet Sheathed Cold-Formed Steel Walls Subjected To Combined Lateral And Vertical Loads, Pengchun Jia, Wenying Zhang, Mahsa Mahdavian, Nathan Derrick, Cheng Yu

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

This paper presents an experimental investigation of the behavior of cold-formed steel (CFS) framed walls sheathed by steel sheets subjected to both lateral and gravity loads. The research focuses were on the collapse limit of the CFS shear wall using steel sheet sheathing and the shear resistance of CFS bearing walls. The test results showed that the gravity load has limited impact to the CFS shear wall’s behavior and performance. The CFS bearing wall could provide considerable shear resistance and it shall be considered in numerical modeling CFS buildings.

Experimental Tests For The Seismic Response Evaluation Of Cold-Formed Steel Shear Walls Sheathed With Nailed Gypsum Boards, Luigi Fiorino, Vincenzo Macillo, Maria Teresa Terracciano, Tatiana Pali, Bianca Bucciero, Raffaele Landolfo

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

The European project named "Energy Efficient LIghtweight-Sustainable-SAfe- Steel Construction" (Project acronym: ELISSA) is devoted to the development and demonstration of cold-formed steel (CFS) modular systems. In particular, these systems are nano-enhanced prefabricated lightweight steel skeleton/dry wall construction with improved thermal, vibration/seismic and fire performance, resulting from the inherent thermal, damping and fire spread prevention properties. The different building performances are studied and improved by means of experimental and numerical activities organized on three scale levels: micro-scale, meso-scale and macro-scale. In particular, the evaluation of the seismic performance is carried out at the University of Naples by means tests on connections …

Seismic Modeling And Incremental Dynamic Analysis Of The Cold-Formed Steel Framed Cfs-Nees Building, J. Leng, S. G. Buonopane, B. W. Schafer

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

The objective of this paper is to present seismic modeling of a two-story cold-formed steel (CFS) framed building. The selected building, known as the CFSNEES building, was designed to current U.S. standards and then subjected to full-scale shake table tests under the U.S. National Science Foundation Network for Earthquake Engineering Simulation (NEES) program. Test results showed that the building’s stiffness and capacity was considerably higher than expected and the building suffered only non-structural damage and no permanent drift, even at maximum considered earthquake (per ASCE 7 and the selected California site) level. Past modeling, including that of the authors, largely …

Experimental Investigation Into Steel Storage Rack Beam-To-Upright Bolted Connections, Liusi Dai, Xianzhong Zhao, Chong Ren

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

For unbraced steel storage racks, the down-aisle stability depends largely on the performance of beam-to-upright connections and column bases. Boltless connections are generally used in order to make rack structures easy to assemble and feasible to adjust the storey height. Recently, storage racks are designed to carry large amounts of goods and they are therefore raise a considerable height, which makes the improvement of the structural stability to be sufficiently important. Under the circumstances, tab-connected beam-to-upright connections with bolts are gradually used in steel storage racks. Compared with boltless connections, the stiffness, strength and ductility of the bolted connections are …

Tilt Bearing Capacity Of Single-Shear Bolted Connections Without Washers, Mehmet E. Uz, Lip H. Teh

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

This paper examines the accuracy of design equations specified in the North American and European codes for cold-formed steel structures in determining the ultimate tilt bearing capacity of single-shear single-row bolted connections without washers in flat steel sheets. It points out that the code equations do not properly distinguish the tilt bearing failure mode from the conventional bearing failure mode, which is typical of double-shear connections and single-shear connections with washers. The tilt bearing capacity is affected by the width of the connected sheet, and its capacity does not vary linearly with either the sheet thickness or the bolt diameter. …

Behaviour Of Cold-Formed Steel Semi Rigid Connections, Ruby Freya, R. Senthil, W. Jeoffray Merin, R. Saravanakumar, Krishna Kuber, M. Gowtham

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

Ductility and inelastic performance are important considerations in aseismic design of buildings. The dissipation of energy due to inelastic deformation is predominantly required in the connections like beam column joints. It is necessary to design these joints as semi rigid for its economic and structural benefits. Semi-rigid connections have highly nonlinear behaviour that makes the analysis and design of frames difficult and complicated. Steel structures are highly regarded for their seismic performance. It is required to understand and study the inelastic behavior of steel connections which would help in an economical and simpler design. This paper involves the modeling of …

Shear Behavior Of Screw Connection Between Cold-Formed Steel And Gypsum Sheathing At Elevated Temperatures, Wei Chen, Yihong Ye

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

The screw connections between cold-formed steel (CFS) and gypsum sheathing play an important role in the axial and lateral performance of CFS wall panels. Previous researches were mainly focus on the shear behavior of such screw connections at room temperature. This paper carried out a preliminary experimental investigation on the mechanical performance of screw connections with single layer gypsum sheathing at elevated temperatures. Limited to the cavity dimension of the furnace, the single-lap test of CFS coupon -fastener-sheathing connection was adopted and compared with the previous test results of sheathing-to-profile screw connections at room temperature. The failure of screw connections …

Monotonic And Cyclic Backbone Response Of Single Shear Sheathing-To- Cold-Formed Steel Screw-Fastened Connections, F. Tao, R. Cole, C. D. Moen

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

Monotonic and cyclic backbone load-deformation response models for single shear plywood, oriented-strand board, and gypsum board sheathing to cold-formed steel screw-fastened connections are developed with support from an experimental program. Connection strength, stiffness, and the probability of screw shear failure are correlated to fastener bearing strength of the two connected plies. Cyclic strength and stiffness degradation was negligible. Cyclic excursions resulted in increased connection stiffness from the screw bearing hardening the ply material and locking in the plies.

Behaviour Of Cold-Formed Steel Trusses With Concentric And Eccentric Joint Arrangements Using The Howick Rivet Connector, Amin Ahmadi, Colin K. L. Yee, Harry J. S. Shepherd, G. Charles Clifton, Raj Das, James B. P. Lim

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

This paper considers the behaviour of a cold-formed steel truss system that uses a novel pinned connector for the joints, to be referred to as the Howick Rivet connector (HRC). Use of the HRC allows a pinned concentric joint arrangement to be formed, as well as the more usual eccentric joint arrangement used in tests described in the literature. However, with the concentric joint arrangement, it is necessary to remove part of the lips of the channel-sections being connected, thus creating a discontinuity in the lips. This paper assesses the effect of this discontinuity. Full-scale truss tests are first described. …

Design Of New Cold Rolled Purlins By Experimental Testing And Direct Strength Method, V. B. Nguyen, B. Cartwright, M. A. English

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

New cold roll formed channel and zed sections for purlins, namely UltraBEAMTM2 and UltraZEDTM2, have been developed by Hadley Industries plc using a combined approach of experimental testing, finite element modelling and optimisation techniques. The new sections have improved strength to weight ratio by increasing the section’s strength by using stiffeners in the section webs. The European standards, Eurocode 3, use a traditional Effective Width Method to determine the strength of a cold formed steel member. However, the design of the new sections UltraBEAMTM2 and UltraZEDTM2 using this method is very complicated in calculating the effective section properties as these …

Seismic Performance Investigation Of Cold-Formed Steel Framed Shear Walls With Steel Sheathing, Feng Ruo-Qiang, Xu Peng-Hui

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

Cold-formed steel (CFS) framed shear walls with steel sheet sheathing can achieve higher shear resistance compared to conventional CFS framed shear walls. Experimental and numerical investigation of seismic behavior was present on two CFS shear walls sheathed with steel sheet for the base layer combined with gypsum wallboards for the face layer on both sides. Monotonic shear and cyclic loading tests were conducted on wall specimens. The failure mechanism, bearing capacity, stiffness and ductility of specimens were obtained. On the basis of rational simplification of CFS framed shear walls, the finite element software ABAQUS was used to simulate the monotonic …

Sheathing Overlapping And Attachment Methods For Cold-Formed Steel Shear Walls With Corrugated Steel Sheathing, Mahsa Mahdavian, Wenying Zhang, Cheng Yu

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

Cold-formed steel (CFS) shear walls sheathed with corrugated steel sheathing are a feasible solution to non-combustible high structural performance CFS shear walls in mid-rise buildings. Corrugated steel sheathings have high in-plane strength and stiffness due to the cross sectional shape of the sheet. This paper presents an experimental study on two specific issues: (1) the sheathing overlapping configurations and their impact to the shear wall performance, (2) the attachment method for sheathing to framing. For the overlapping issue, one overlap and two overlaps in the corrugated sheets were experimentally investigated, it was found that the overlap differences did not cause …

Utilizing Vegetation Indices As A Proxy To Characterize The Stability Of A Railway Embankment In A Permafrost Region, Priscilla Addison, Pasi T. Lautala, Thomas Oommen

Michigan Tech Publications, Part 1

Degrading permafrost conditions around the world are posing stability issues for infrastructure constructed on them. Railway lines have exceptionally low tolerances for differential settlements associated with permafrost degradation due to the potential for train derailments. Railway owners with tracks in permafrost regions therefore make it a priority to identify potential settlement locations so that proper maintenance or embankment stabilization measures can be applied to ensure smooth and safe operations. The extensive discontinuous permafrost zone along the Hudson Bay Railway (HBR) in Northern Manitoba, Canada, has been experiencing accelerated deterioration, resulting in differential settlements that necessitate continuous annual maintenance to avoid …

Designing A Continuously Variable Magnetic Gear, J. Pritchard, Pavithra Padmanathan, Jonathan Z. Bird

Electrical and Computer Engineering Faculty Publications and Presentations

This paper investigates the performance capabilities of a continuously variable magnetic gearbox that utilizes a flux focusing rotor structure. A fractional slot stator winding is designed to couple to the outer rotor of an existing magnetic gearbox in order to enable the magnetic gearbox to operate with a variable gear ratio.

Groundwater Restoration Following In-Situ Leach Mining Of Uranium, Omar A. Ruiz Lopez

Civil Engineering ETDs

From 1950 to the early 1980’s New Mexico played an important role in the production of uranium (U) for the nuclear power industry and the nation’s weapon programs. Though the U mining and milling industry in New Mexico is inactive at present, increased interest in nuclear energy as a CO₂ free power source has led to proposals for renewed development of U resources. In particular, U mining projects have been proposed using both underground mining and in situ leach (ISL) mining. When feasible, ISL mining minimizes waste by eliminating; mine waste, mine dewatering, radiation exposure and the recovered U …

Rapid Deployment Indoor Localization Without Prior Human Participation, Han Xu, Zimu Zhou, Longfei Shangguan

Research Collection School Of Computing and Information Systems

In this work, we propose RAD, a RApid Deployment localization framework without human sampling. The basic idea of RAD is to automatically generate a fingerprint database through space partition, of which each cell is fingerprinted by its maximum influence APs. Based on this robust location indicator, fine-grained localization can be achieved by a discretized particle filter utilizing sensor data fusion. We devise techniques for CIVD-based field division, graph-based particle filter, EM-based individual character learning, and build a prototype that runs on commodity devices. Extensive experiments show that RAD provides a comparable performance to the state-of-the-art RSSbased methods while relieving it …

Dielectric Characterization Of Mylar And The Effects Of Doping Processes, Cami B. Belcher

Chemical and Biological Engineering ETDs

Mylar® polymer is a bi-axially oriented polyethylene terephthalate (PET) polymer film used widely as a dielectric, specifically in capacitors. The dielectric characteristics of Mylar have been well studied and documented over the years; however, many of the mechanisms responsible for dielectric breakdown and failure are not understood for modified versions of the material. Previous studies on Mylar confirm that factors such as temperature, humidity, and voltage ramp rates can also have a significant effect on the dielectric properties and measurement of the dielectric properties. This study seeks to determine how dielectric properties, including permittivity, dielectric loss, and breakdown strength, are …

Accident Rates, Phase Of Operations, And Injury Severity For Solo Students In Pursuit Of Private Pilot Certification (1994–2013), Douglas Boyd, Peter Dittmer

Journal of Aviation Technology and Engineering

Flight training accidents constitute 14% of general aviation accidents. Herein we determined the rates, injury severity, and phase of flight for primary student solo accidents/incidents (mishaps) in Cessna 172 aircraft.

Mishaps over the period spanning 1994–2013 were identified from the NTSB database. Student population data were from the FAA. Statistics employed proportion tests, Poisson distribution, and Mann-Whitney tests.

Across the study period, 598 mishaps were identified. While the mishap rate increased nearly two-fold between 1994/1997 and 2002/ 2005, a 35% decline was evident thereafter. Nevertheless, no statistical difference in mishap rates was evident between the initial and current periods. Over …

Material Properties Of Cold-Rolled Thin-Walled Steel Plates At Elevated Temperatures, Zhen Nie, Yuanqi Li

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

It is highly important to clarify the high temperature mechanical properties in the design of cold-formed steel structures under fire condition due to the unique deterioration feature in material properties under fire environment and associated reduction to the mechanical performance of members. This paper presents the material properties of coupons cut from raw cold-rolled thin-walled steel plates at elevated temperatures. A set of high temperature extensometer with a range of 12.5mm relative to 50mm gauge was employed in the experiments, which could collect more displacement data between the gauge scope before the coupon fail. The coupons were extracted from original …

Peridynamic Modeling Of Ruptures In Biomembranes, Michael Taylor, Irep Gözen, Samir Patel, Aldo Jesorka, Katia Bertoldi

Mechanical Engineering

We simulate the formation of spontaneous ruptures in supported phospholipid double bilayer membranes, using peridynamic modeling. Experiments performed on spreading double bilayers typically show two distinct kinds of ruptures, floral and fractal, which form spontaneously in the distal (upper) bilayer at late stages of double bilayer formation on high energy substrates. It is, however, currently unresolved which factors govern the occurrence of either rupture type. Variations in the distance between the two bilayers, and the occurrence of interconnections (“pinning sites”) are suspected of contributing to the process. Our new simulations indicate that the pinned regions which form, presumably due to …

On The Direct Strength Design Of Cold-Formed Steel Columns Falling In Local-Distortional Interactive Modes, André Dias Martins, Dinar Camotim, Pedro Borges Dinis

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

This paper present and discusses proposals for the codification of efficient design approaches for cold-formed steel columns affected by local-distortional (L-D) interaction. These proposals, based on the Direct Strength Method (DSM), were developed, calibrated and validated on the basis of experimental and numerical (shell finite element) failure load data concerning columns with several cross-section shapes and obtained from investigations carried out by various researchers. Three types of L-D interaction are taken into account, namely “true L-D interaction”, “secondary local bifurcation L-D interaction” and “secondary distortional bifurcation L-D interaction”. Moreover, previously available DSM-based design approaches to handle column L-D interactive failures …

Powerful Artificial Muscles For Morphing Composites And Other Applications, Ray Baughman

Composites at Lake Louise (CALL 2015)

Three successive generations of twist-spun artificial muscles are described and used to make morphing composites and textiles that are electrically, thermally, or chemically powered.¹ Our first generation of twist-spun muscles, which are electrochemically powered by volume changes induced by double-layer charge injection, provide torsional rotation speeds of 590 rpm, and torsional strokes of 250° per millimeter of actuator length, which is 1000 times that for earlier artificial muscles. Our second generation muscles, which require no electrolyte and are based on guest-infiltrated carbon nanotube yarns, can torsionally actuate at 11,500 rpm and deliver 85 times higher power density during contraction …

Buckling Strength Of Cold-Formed Circular Steel Column Subjected To Axial Load, Ayana Ito, Nobutaka Shimizu, Keiichi Sato, Yoshimichi Kawai

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

In this study, the global buckling behavior of a cold-formed circular steel column was discussed with a focus on the effects of its mechanical properties and initial imperfections on the behavior. As the first step, the stress–strain curves of the column under tensile and compressive loads as well as its residual stresses were investigated. Subsequently, a finite element analysis was conducted to clarify if the analysis properly simulated the stub column behavior. The analysis results obtained using measured compressive stress–strain curves and residual stresses agreed well with experimental results. Finally, another finite element analysis was performed on the long column …

Proposal For Codification Of A Dsm Design Approach For Cold-Formed Steel Short-To Intermediate Angle Columns, Pedro Borges Dinis, Dinar Camotim

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

This paper presents a proposal for the codification of an efficient design approach for cold-formed steel short-to-intermediate equal-leg angle columns, consisting of a slight modification of a design approach developed by Dinis & Camotim (2015) and based on the Direct Strength Method (DSM). After (i) collecting the available experimental and numerical failure load data, comprising fixed-ended and pin-ended columns with several geometries (cross-section dimensions and length) and reported by various researchers, and (ii) briefly reviewing the mechanical reasoning behind the proposed procedures, the search for new/simpler expressions to provide the DSM design curves is addressed. Their merits are assessed through …

Experimental Investigation Of Cold-Formed C-Sections With Central Square Holes In Shear, Cao Hung Pham, Andreas Pelosi, Thomas Earls, Gregory J. Hancock

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

The North American Specification S100:2012 Edition has recently included DSM design rules for unperforated channel sections in shear. However, there are no rules presented in this standard for the DSM in shear for sections with holes. Recently, a testing program has been performed at the University of Sydney to determine the ultimate strength of high strength cold-formed C-sections with a thickness of 1.5 mm and central square holes of varying sizes. Three different sizes of the square holes were chosen for testing. For thin sections, the DSM shear curve was found to be applicable for design of sections with square …

Flight Emergency Advice Works Just As Well Back On The Ground, Carolyn Massiah

UCF Forum

Save yourself first!

This one sentence is a valuable piece of advice I wish I had received and fully embraced so much earlier in life. In fact, it is still a notion that I struggle with because it is one that sounds selfish in nature. However, now more than at any other point in my life, I realize that in order to be selfless and to be able to assist others, you must first truly work on thinking of your own self first.

Evaluation Of Ultrasound Assisted Potassium Permanganate Pre-Treatment Of Spent Coffee Waste, Rajeev Ravindran, Swarna Jaiswal, Nissreen Abu-Ghannam, Amit Jaiswal

Articles

In the present study, novel pre-treatment for spent coffee waste (SCW) has been proposed which utilises the superior oxidising capacity of alkaline KMnO₄ assisted by ultra-sonication. The pre-treatment was conducted for different exposure times (10, 20, 30 and 40 min) using different concentrations of KMnO₄ (1,2, 3, 4, 5% w/v) at room temperature with solid/liquid ratio of 1:10. Pretreating SCW with 4% KMnO₄ and exposing it to ultrasound for 20 min resulted in 98% cellulose recovery and a maximum lignin removal of 46%. 1.7fold increase in reducing sugar yield was obtained after enzymatic hydrolysis of KMnO_{4 …}

Web Crippling Strength Of Cold-Formed Duplex Stainless Steel Lipped-Channel Sections With Web Openings Subjected To Interior-One-Flange Loading, Amir M. Yousefi, James B. P. Lim, Asraf Uzzaman, Ying Lian, G. Charles Clifton, Ben Young

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

Cold-formed stainless steel sections are becoming more widely used in the residential and commercial sectors due to their high corrosion resistance and high strength-to-weight ratio. However, their susceptibility to web crippling at points of concentrated loading is well-known to be an important design issue. In addition, web openings are also become popular, as they improve ease of installation of services. This paper presents the results of an investigation into the effect of web crippling on cold-formed duplex stainless steel lipped channel-sections, having such openings, under the interior-one-flange (IOF) loading condition. 742 non-linear elasto-plastic finite element analyses are undertaken, with web …

Progress In The Development Of Asce 41 For Cold-Formed Steel, Deniz Ayhan, Robert L. Madsen, Benjamin W. Schafer

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

The objective of this paper is to document progress on new cold-formed steel provisions for the forthcoming edition of ASCE 41, Seismic Evaluation and Retrofit of Existing Buildings. The current edition of ASCE 41 (2013) is weak with respect to the application of cold-formed steel and provides only limited information on cold-formed steel framed buildings, shear walls, members, and connections. The emphasis in this paper is on cold-formed steel framed shear walls, and the development of modeling parameters that characterize the backbone shear-deformation response, and acceptance criteria that provide allowable demand-to-capacity ratios (m-factors) for the shear walls based on a …