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Commentary On The Standard For Cold-Formed Steel Framing Prescriptive Method For One And Two Family Dwellings, 2001 Edition With 2004 Supplement, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject.

With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. It is anticipated that AISI will publish updates of …

Standard For Cold-Formed Steel Framing -- Prescriptive Method For One And Two Family Dwellings, 2001 Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject.

With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. It is anticipated that AISI will publish updates of …

Standard For Cold-Formed Steel Framing – Wall Stud Design, 2004 Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included in the Commentary.

With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. It is …

Niel Calculations For High-Energy Heavy Ions, John W. Wilson, I. Jun, M. A. Xapsos, E. A. Burke, F. F. Badavi, L. W. Townsend

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Calculations of NIEL are reported for heavy ions prominent in the space environment for energies ranging from 200 MeV per nucleon to 2 GeV per nucleon.

Indentation Of A Square Elastomeric Thin Film By A Flat-Ended Cylindrical Punch In The Presence Of Long-Range Intersurface Forces, Bing Feng Ju, Kai-Tak Wan, Kuo Kang Liu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper reports an experimental study of the elastic deformation of a 200 μm thick microfabricated square membrane with sides ranging from 8.5 mm to 15 mm as indented by a fine cylindrical, flat-ended punch with diameter 500 μm in the presence of long-range intersurface forces. an apparatus was constructed to allow simultaneously measurements of the indenter displacement and the applied force. a number of interesting phenomena such as the "jump-into-contact" and the "pull-off" between the membrane and the moving cylinder were observed. a simple theoretical analysis using linear elasticity was adopted to fit the load-displacement curve (compliance) and thus …

Modeling Of Multi-Converter More Electric Ship Power Systems Using The Generalized State Space Averaging Method, Madan M. Jalla, Ali Emadi, Geoffrey A. Williamson, Babak Fahimi

Electrical and Computer Engineering Faculty Research & Creative Works

based on the more electric ship (MES) concept, conventional mechanical, hydraulic, and pneumatic power transfer systems are replaced by electrical systems in different sea vehicles. Considering different levels of power requirements of various electrical loads and for the achievement of compact, light, safe, and efficient power supplies, implementation of multi-converter power electronics-based power systems is the most feasible option in the development of advanced navy vehicles. This paper presents a modular approach for the modeling and simulation of multiconverter MES power systems based on the generalized state space averaging method. MES power systems may consist of many individual converters connected …

Multiobjective Optimization Of Seismic Structures, Franklin Y. Cheng, Dan Li, Jeffrey Ger

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents a constrained Mult objective optimization method in the form of a robust, practical, problem-independent formulation based on genetic algorithm combined with game theory and investigates the effect of Mult objective optimization on structural design. the study includes objectives, constraints, and design variables as well as their effect on structural design and behavior. the algorithm comprises - Mult objective fitness function, niche method, and Pareto set filter. a 10-story setback building is used to illustrate the evaluation of three choices: steel frame, reinforced concrete frame, composite steel and reinforced concrete frame. Evaluation is based on economics as well …

Overview Of The Japanese Guidelines For Seismic Retrofitting Of Rc Columns Using Frp Materials, Gustavo Tumialan, Hiroshi Fukuyama, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The increasing uses of FRP materials for the strengthening and upgrade of buildings has motivated the international engineering community to produce guidelines for the proper design, handling and installation of the externally bonded FRP systems. Thus, independent efforts coordinated by different organizations such as the Japan Building Disaster Prevention Association (JBDPA) and the American Concrete Institute (ACI) have led to implementing appropriate provisions. the JBDPA guidelines mainly focus on seismic retrofitting of structural elements, which implies the strengthening for shear of deficient structural elements. This paper describes and comments on some of the design approaches provided by the JBDPA guidelines …

Strengthening Of Masonry Structures With Frp Composites, J. Gustavo Tumialan, Francesco Micelli, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Unreinforced masonry (URM) walls are prone to failure when subjected to out-of-plane and in-plane loads. the development of effective and affordable strengthening strategies is a need. in this context fiber reinforced polymer (FRP) materials offer viable solutions to solve or lessen the effects of overloading. This paper describes FRP systems proposed for use in the strengthening of masonry elements as well as the impact of such systems on the building being retrofitted. Also, field applications, some potential and others already implemented applications, are described. Field applications include strengthening for natural hazards (i.e. earthquakes and high wind pressures) as well as …

Evaluating The Repair Of System-On-Chip (Soc) Using Connectivity, Minsu Choi, Nohpill Park, Vincenzo Piuri, Fabrizio Lombardi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a new model for analyzing the repairability of reconfigurable system-on-chip (RSoC) instrumentation with the repair process. It exploits the connectivity of the interconnected cores in which unreliability factors due to both neighboring cores and the interconnect structure are taken into account. Based on the connectivity, two RSoC repair scheduling strategies, Minimum Number of Interconnections First (I-MIN) and Minimum Number of Neighboring Cores First (C-MIN), are proposed. Two other scheduling strategies, Maximum Number of Interconnections First (I-MAX) and Maximum Number of Neighboring cores First (C-MAX), are also introduced and analyzed to further explore the impact of connectivity-based repair …

An Assessment Of In-Situ Frp Shear And Flexural Strengthening Of Reinforced Concrete Joists, Annaiah Raghu, John J. Myers, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study examines the in-situ shear performance and modes of failure of reinforced concrete (RC) T-beams (joists) strengthened with externally bonded carbon fiber reinforced polymer (CFRP) sheets. the experimental program consisted of testing a series of nine structural components at the Malcom Bliss Hospital, in St. Louis, Missouri. the members were tested to validate the different systems and techniques of strengthening. in particular, this paper covers cases of U-Wraps with and without end-anchors. the experimental results clearly indicate the contribution of externally bonded CFRP sheets in increasing the shear capacity of the system. the experimental and theoretical shear strength of …

Field Evaluation Of Unreinforced Masonry Walls Strengthened With Frp Composites Subjected To Out-Of-Plane Loading, Gustavo Tumialan, Davide Tinazzi, John J. Myers, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Unreinforced masonry (URM) walls at a decommissioned building in St. Louis, Missouri were tested to failure. the walls belonging to the present experimental program were subjected to out-of-plane loading. Previous work on URM and reinforced masonry walls strengthened with FRP laminates has shown remarkable increases in capacity and ductility. However, most of this research has been conducted under laboratory conditions, where, many times, it is a difficult task to represent real field conditions. in this context, this experimental program offered a singular opportunity for performing field experimentation on URM walls strengthened with Glass, Aramid and Carbon Fiber Reinforced Polymers (GFRP, …

Real Time State Estimation Of Multi-Converter More Electric Ship Power Systems Using The Generalized State Space Averaging Method, Madan M. Jalla, Ali Emadi, Geoffrey A. Williamson, Babak Fahimi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a real time state estimation algorithm for control and security maintenance of multi-converter MES power electronic systems. Estimation of the state variables of the system includes the effects of ripples and converter switching actions. the proposed state estimator is based on the Weighted Least Squares (WLS) approach. Generalized state space averaging technique in which we consider the DC value of the state variables, and their harmonics is used to model DC/DC converters for the state estimator. in this paper, after introducing the proposed approach and the concept of security and control assessments, results of applying the proposed …

Analysis And Control Of A Buck Dc-Dc Converter Operating With Constant Power Load In Sea And Undersea Vehicles, Claudio Rivetta, Ali Emadi, Geoffrey A. Williamson, Ranjit Jayabalan, Babak Fahimi

Electrical and Computer Engineering Faculty Research & Creative Works

Power electronics based zonal DC power distribution systems are being considered for sea and undersea vehicles. the stability of the DC power electronics-based power distribution systems is a significant design consideration because of the potential for negative impedance induced instabilities. in this paper, dynamic properties and control of a buck converter feeding a downstream DC-DC converter are studied. the controller in this system combines an instantaneous current feedback loop using hysteresis with a proportional-integral algorithm to regulate the output voltage of the converter. based on a large-signal averaged model of the converter, the stability-in-large around the operation point is presented. …

Applications Of Power Electronics-Based Systems In Vehicular Technology: State-Of-The-Art And Future Trends, R. Jayabalan, Babak Fahimi, A. Koenig, Steven Pekarek

Electrical and Computer Engineering Faculty Research & Creative Works

Power electronics-Based systems and components have been increasingly used in land, air, and sea vehicles over the past decade. This has turned the vehicular products into a primary market for power electronics applications. Moreover, the existing trend in more electrification of the vehicles represents an even bigger potential for an increase in the existing demand. Although the primary incentive for introduction of multi-converter systems into vehicular technologies was to enhance fuel economy and environmental issues associated with vehicles; today, improvement of fault tolerance, cost, and compactness have boosted the motivation for development of the more electric vehicles. the use of …

Additive-Assisted Cerium-Based Electrolytic Coating Process For Corrosion Protection Of Aluminum Alloys, James O. Stoffer, Thomas J. O'Keefe, Eric L. Morris, Scott Hayes, Paul Yu, Alex Williams, Xuan Lin

Chemistry Faculty Research & Creative Works

The corrosion resistance of an aluminum or aluminum alloy component is enhanced by immersing an aluminum alloy to act as a cathode and an oxygen-evolving anode in an electrolyte comprising water, cerium ions, and an additive selected from among animal gelatin, derivatives of animal gelatin, and amino acids, then passing an electrical current through the electrolyte to deposit a cerium-based coating onto the aluminum-based component.

Interfacial Stability Of Electrodeposition Of Cuprous Oxide Thin Films, Partho Neogi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experiments on deposition of Cu₂O films from basic cupper sulfate solution show that copper also deposits. At low, but basic values of pH only copper deposits and at high pH only cuprous oxide deposits. In the intermediate range where both compete the system shows oscillations at "constant current." Linear stability analysis has been conducted for such an electrochemical cell to show that oscillations can take place in the parameter space identified in the experiments. The results are keeping with most of the experimental observations, which are many, but not with all. The physical mechanisms behind the oscillations are …

Elastomer Reclaiming Composition And Method, Michael W. Rouse, Victor M. Deeb, Morgan L. White, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The present invention relates to elastomeric compositions and methods including compositions and methods involving the use of aromatic alcohols. The present invention further relates to elastomeric compositions that can include ground reclaimed elastomeric particles. Compositions of the present invention are usable in numerous elastomeric applications including interior and exterior vehicle parts, roofing, asphalt, and any other applications that employ an elastomer as an ingredient thereof, particularly those utilizing rubber or a similar elastomer.

The present invention further is directed to asphalt compositions and their methods of manufacture and use.

Ultimate Strength Of A Continuous Decking Of Cold-Drawn Low-Ductility High Strength Steel, A. Monayem Akhand, W. H. Wan Badaruzzaman, Kosai A. Sanjery

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

Profiled decking of cold-drawn low-ductility high strength steel is a relatively new introduction to composite floor construction. This type of decking shows high sensitivity to distortional as well as local buckling. Prediction of ultimate strength of such decking in continuous configuration is not adequately covered in any of the analytical methods of modern day codes. Instead, due to inadequate guidance, various design codes currently apply additional restrictions on their design and use. The support moment-rotation and ultimate moment of resistance of such decking are the two most important parameters in designing such decking as continuous structure for the construction stage …

Web Crippling Of Cold Formed Steel Multi -Web Deck Sections Subjected To End One-Flange Loading, J. A. Wallace, R. M. Schuster

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

Presented in this paper are the results of a study where the web crippling capacity of multi-web deck sections subjected to End One-Flange loading (EOF) was investigated. A total of 148 tests were completed. New coefficients were established using the data from this study and any appropriate data from previous work. New resistance factors and factors of safety were also established. Also investigated in this study was the web crippling capacity of partially fastened deck sections and re-entrant deck type sections subjected to EOF loading. Seventy-seven (77) partially fastened multi-web decks and 36 re-entrant decks were tested in this study. …

Behavior Of Complex Hat Shapes Used As Truss Chord Members, Nuthaporn Nuttayasakul, W. Samuel Easterling

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

Cold-formed steel roof truss systems that use complex hat shape members for both top and bottom chord elements are a growing trend in the North America steel framing industry. When designing cold-formed steel sections, a structural engineer typically tries to improve the local buckling behavior of the coldformed steel elements. The complex hat shape has proven to limit the negative influence of local buckling. However, a distortional buckling mode can be the control mode of failure in the design for the chord member with an intermediate un-braced length. The chord member may be subjected to both bending and compressive load …

Channel Section Beams Under Static And Impact Loading, J. Rhodes, M. Macdonald

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

The elasto-plastic behaviour of plain channel section beams under central point loading is investigated under static and impact loading conditions. Two different loading set-ups are considered, the first in which the load is applied to cause compression at the flange free edges and the second in which the load is applied to cause tension at the flange free edges. For each of these load set-ups static loading tests, single impact loading tests and multiple impact loading tests are carried out on a total of 86 channel beams. The energy absorption behaviour of the beams tested is examined and the static …

Cold-Formed Steel Examples To The Theory And Finite Element Implementation Of Plasticity, Herm Hofmeyer

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

This paper presents two examples to the theory and finite element implementation of plasticity. The first example is on the cross-sectional behavior of trapezoidal sheeting subjected to a concentrated load. It is shown that the number of elements (and thus the number of integration points) along the comer radius are important for the correct modeling of this static problem. The second example is on the failure of first-generation sheeting subjected to a concentrated load and a bending moment. This problem, especially for large span lengths, can be solved only with explicit dynamic simulations. These are, for our research field, for …

Shear Stiffness Of Pallet Rack Upright Frames, S. Sambasiva Rao, R. G. Beale, M. H. R. Godley

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

PaIIet racks, often fabricated using cold-formed steel, are used for the storage of goods. Uprights of these racks are braced in the cross-aisle direction forming a frame, which behaves like a built-up column. Evaluation of the shear stiffness of this frame is needed to determine the buckling load. Currently two approaches prevail in the rack industry to determine the shear stiffness. The RMI code uses a theoretical formula and the FEM code requires testing. There is a considerable difference in the stiffness values determined by two approaches. The present paper describes experimental and numerical studies conducted at Oxford Brookes University …

Tests Of Storage Rack Channel Columns With Rear Flanges, Nabil Abdel-Rahman, Ashraf Fadel, Mohamed Ei-Sadaawy, Sherif Mourad

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

An experimental study was performed to investigate the ultimate strength and modes of failure of axially loaded channel rack columns with rear flanges. A total of 16 column specimens fabricated by press-brake forming method were tested up to failure. The material properties of the column specimens were determined using standard tensile coupon tests. The deformation and stress behavior of the tested columns were monitored using displacement transducers and strain gauges. The effects of column slenderness ratio, thickness, perforation, and end conditions on the column ultimate strength and mode of failure were studied. The test failure loads were compared to the …

Initial Geometrical Imperfections In Three-Storey Modular Steel Scaffolds, W. K. Yu, K. F. Chung, S. L. Chan

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

Modular steel scaffolds are commonly used as supporting scaffolds in building construction. They are highly susceptible to global and local instability, and traditionally, the load carrying capacities of these scaffolds are obtained from limited full-scale tests with little rational design. Structural failure of these scaffolds occurs from time to time due to inadequate design, poor installation and over-loads on sites. Initial geometrical imperfections are considered to be very important to the structural behaviour of multi-storey modular steel scaffolds. This paper presents an extensive numerical investigation on three different approaches in analyzing and designing multi-story modular steel scaffolds, namely, a) Notional …

Experimental Investigation Of Distortional Buckling Of Cold-Formed Stainless Steel Sections, Maura Leece, Kim J. R. Rasmussen

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

This paper describes the experimental investigation of the distortional buckling of thin-walled stainless steel sections in compression. Austenitic 304, ferritic 430 stainless steel and ferritic-like 3Crl2 chromium weldable steel sheets were brake-pressed into simple-lipped channels and simple-lipped channels with intermediate stiffeners. A comprehensive procedure to determine the mechanical properties of stainless steel material is described. A total of 19 distortional tests failed at stresses greater than the proportionality stress, and hence were influenced by material non-linearity. Data required to assess current design guidelines in place for distortional buckling of stainless steel compression members are provided herein.

Introduction To The Theory And Finite Element Implementation Of (Steel) Plasticity, Herm Hofmeyer

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

This paper tries to enlighten the subject of (numerical) plasticity by presenting fundamental theory and some very practical examples. For a two-dimensional plain stress state, a Hubert-Henky yield criterion is derived. The flow rule is discussed, including an explanatory numerical example. The yield criteria and flow rule are theoretically applied in a four node finite element. This element is used to show some of the conditions and limitations of a plastic calculation in the finite element method. Finally, a real finite element calculation is made for illustrating the theory derived.

Design Of Cold-Formed Stainless Steel Sections With Single Web Subjected To Web Crippling, Feng Zhou, Ben Young

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

An experimental investigation of cold-formed stainless steel hollow sections subjected to web crippling is presented in this paper. Tests were conducted on square and rectangular hollow sections of austenitic stainless steel type 304. Tensile and compression coupon tests were performed to obtain the longitudinal tension and transverse compression material properties. The web crippling tests were conducted under two loading conditions for End-Two-Flange (ETF) and Interior-Two-Flange (ITF) specified in the current American Specification and Australian/New Zealand Standard for cold-formed stainless steel structures. The test strengths obtained from this study and the test strengths of stainless steel lipped channel sections under End-One-Flange …

Design Of Stainless Steel Sections Against Distortional Buckling, Maura Leece, Kim J. R. Rasmussen

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

Current cold-formed stainless steel design codes for distortional buckling, including the Australian/New Zealand Standard AS/NZS 4673 (2001) and the North American ASCE (2002), have been based on cold-formed carbon steel codes without the support or corroboration of experimental evidence. As such, an experimental program on the distortional buckling of axially compressed, cold-formed stainless steel simple lipped channels and lipped channels with intermediate stiffeners was conducted. Results show that the effect of stainless steel material non-linearity is partially negated by the strength-enhanced corners, and this becomes evident in the design evaluation. Both the effective width and the "direct strength" (ASINZS 4600 …