Engineering Commons^™

Soil Dynamics Course In Curriculum, Deepankar Choudhury

Forum for Promotion of Soil Dynamics in India

No abstract provided.

A Study Of Mobile Learning For Higher Education Students In Guangzhou, Chun Hung, Hugo Wong

Practical Social and Industrial Research Symposium

No abstract provided.

Assisted Technology For Daily Living, Raymond K.Y. Tong

Practical Social and Industrial Research Symposium

Prof Tong will introduce two major assisted technologies he recently developed to assist elderly people’s daily living and promote healthy ageing : i) the telecare system for monitoring the safety of single elderly at home; and ii) Kinect system for elderly to carry out home-based exercise.

On Translating Technology Research Into Industrial Applications, Stephen T.C. Wong

Practical Social and Industrial Research Symposium

Using personal cases he previously experienced, Prof Wong will share with colleagues the influence of environments and market forces that drive the applied technology research into practice. The speech will be delivered in an informal, interactive format, rather than didactic.

Mechatronics In Electrical Efficiency And Environmental Impact, Sherif Hyseni

UBT International Conference

This paper focuses on the mechatronic technology development, and its influent on electrical efficiency with a direct result in cost and environment. Considering the well-known European Union standard “20-20-20” and the possibility and responsibility of Kosovo in this field, the role of energy efficiency has great impact for future directions. This paper refers to a new technology solution for heating that is available on the local market, called “DAIKIN” by analyzing the functionality of this device and its promise to save up to 40% of the heating costs. Implementation of “DAIKIN” technology in state institutions in Prishtina, and also the …

The History Of Space Debris, Loretta Hall

Space Traffic Management Conference

This paper examines what space debris consists of and where it came from. In 1958, astronomer Clyde Tombaugh published the results of his research into the existence of natural debris near the Earth, concluding that no such debris existed. During the ensuing fifty-five years, man-made debris has been accumulating to the point that it threatens launches, active satellites, and the International Space Station. NASA reported that as of 2013, more than 21,000 pieces the size of a softball or larger were being tracked, as were about 500,000 pieces at least the size of a marble and “many millions” of pieces …

An Integrated Approach To Orbital Debris Research And Management, Marshall H. Kaplan

Space Traffic Management Conference

A viable space traffic management program faces a great barrier caused by the ever-increasing number and variety of orbiting objects ranging in size from a few microns to several meters. Although several international agreements to limit the growth rate of orbital debris are in place, the risk of damage and destruction to active satellites is continually rising. The urgency of this situation was highlighted by the 2007 Chinese ASAT test and the collision of Iridium and Cosmos satellites in 2009. Although many debris removal techniques have been posited none have been implemented. Unless a space debris reduction program is undertaken …

Weather Research Requirements To Improve Space Launch From Cape Canaveral Air Force Station And Nasa Kennedy Space Center, William P. Roeder, Lisa L. Huddleston, William H. Bauman Iii, Kelly B. Doser

Space Traffic Management Conference

Weather has a large affect on operations at Cape Canaveral Air Force Station (CCAFS) and NASA Kennedy Space Center (KSC). Weather is the leading source of scrubs and delays to space launch from CCAFS/KSC. Weather has an even larger impact on ground processing as space launch vehicles and payloads are prepared in the months before space launch. Many of those operations are very sensitive to weather. In addition, the weather in Florida is notoriously difficult to predict, especially during the summer when rapid deep convection can occur in minutes. Finally, the weather can be extremely subtle in this area during …

Calculation For Moment Capacity Of Beam-To-Upright Connections Of Steel Storage Pallet Racks, Tuo Wang, Xianzhong Zhao, Yiyi Chen

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

Steel storage pallet rack structures are three-dimensional framed structures, which are widely used to store different kinds of goods. For the easy accessibility to stored products, pallet racks are not usually braced in the down-aisle direction. The down-aisle stability is mostly provided by the characteristics of beam-to-upright connections, and the characteristics of upright base connections. In this paper, calculation for moment capacity of beam-to-upright connections is carried out. A mechanical model is presented firstly. Based on the model, moment capacity is related to the failure capacity, directly determined by the failure mode, of the topmost tab of the beam-end-connector and …

Design Method Of Bending Load-Carrying Capacity For Sandwich Panels With Different Metal Panel On Both Sides, Yanli Guo, Xingyou Yao, Kai Liu

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

The sandwich panels, with plain and shallow grain pressed metal plate as the face sheets, and glass wools, rigid polyurethane foam, and rock wools as core materials, have excellent heat insulation and mechanical behavior, and been used as curtain walls for tall buildings in recent years in China. Since wind load and temperature action are the main actions for curtain walls, the sandwich panels are flexural members. In this paper, the design method and design formula of flexural load-carrying capacity and flexural deflection of a kind of sandwich plates with different metal panel on both sides are discussed and proposed. …

Study On The Flexural Capacity Of Cold-Formed Steel Joists-Osb Composite Floors, X. H. Zhou, Y. Shi, R. C. Wang, Y. J. Liu

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

Two full scale specimens were tested to study the flexural capacity of cold-formed steel joists and OSB (Oriented strand board) composite floors. Test results indicated the composite floors had high bearing capacity and small deformation, and the screw spacing significantly affected the load-carrying capacity. The main failure modes were flexural and torsional buckling of floor joist, and the interactive buckling of compression flange, web and crimp. The wave length of bucking equalled to the adjacent screw spacing. Then the specimens were analyzed by commercial software ANSYS and the nonlinear FEM calculation results agreed well with the test results. Furthermore, detailed …

Finite Element Modeling Of New Composite Floors Having Cold-Formed Steel And Concrete Slab, Yazdan Majdi, Cheng-Tzu Thomas Hsu, Mehdi Zarei

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

In this research, the structural behavior of a new type of U.S. patented composite floor system is explored through finite element modeling. The new composite floor incorporates cold-formed (light-gauge) steel profiles as the joist on bottom, a corrugated steel deck as the formwork for concrete, a hat channel (furring channel) as the continuous shear connector and finally a concrete slab on top. All steel parts in the system are cold-formed and connected together by self-drilling fasteners. In this study, a comprehensive three-dimensional finite element modeling is performed for the composite floor system. A local bond-slip model is applied to simulate …

Innovative Cold-Formed Steel Framed Shear Wall Sheathed With Corrugated Steel Sheets: Experiments And Dynamic Analysis, Cheng Yu, Guowang Yu, Jie Wang

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 in high wind and seismic zones due to its advantages of non-combustibility, high shear strength, and high stiffness. However recent research projects showed that the corrugated steel sheathing demonstrated low ductility. This paper presents an experimental study aimed at improving the ductility of cold-formed steel shear walls sheathed with corrugated steel sheathing. A method of using opening in the sheathing is employed to improve the shear wall’s ductility meanwhile controlling the damage locations and failure mechanism. A total of …

Bond-Slip Characteristics Between Cold-Formed Metal And Concrete, Yazdan Majdi, Cheng-Tzu Thomas Hsu, Sun Punurai

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

Composite action in systems consisting of steel and concrete depends on an effective shear-transfer mechanism between the two materials. Such mechanism for smooth steel surfaces inside concrete will be limited to the bond-slip behavior at the steel/concrete interfaces. This research investigates the bond-slip behavior of galvanized cold-formed (light gauge) steel profiles embedded in concrete. A new innovative pull-out test is presented and global bond-slip curves for different values of concrete strength are obtained from such tests. Next, through an innovative procedure, mathematical equations and a few points from the experimental global bond-slip curves are used to develop a bi-linear local …

Simplified Seismic Design For Mid-Rise Buildings With Vertical Combination Of Cold-Formed Steel And Concrete Framing, X. L. Yuan, L. Xu

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

Presented in this paper is a practical approach for the seismic design of mid-rise buildings with vertical combination of cold-formed steel and concrete framing. In current design practice the presence of vertical irregularities on both mass and stiffness inherited in such building structures creates a challenge for the seismic design. Currently, a two stage lateral force procedure prescribed in ASCE 7 is prescribed for evaluating the seismic load if the lateral stiffness of the lower structure of the building is considerably more rigid than the upper one. In the proposed approach the requirement associated with the two stage analysis procedure …

Fastener-Based Computational Models With Application To Cold-Formed Steel Shear Walls, G. Bian, S. G. Buonopane, Hung Huy Ngo, Benjamin W. Schafer

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

The objective of this paper is to validate a tool that design engineers could employ to develop mechanics-based predictions of the lateral response of wood-sheathed cold-formed steel (CFS) framed shear walls applicable in a wide variety of situations. Wood framed shear walls enjoy a variety of tools, most notably SAPWood and its predecessor CASHEW, that provide a means to predict the complete hysteretic behavior of a shear wall based on the nail fastener schedule and board selection. The existence of these tools helps engineers in unique design situations, encourages innovation in shear wall design particularly for Type I shear walls, …

Improvements To The Prediction Of Brace Forces In Z-Purlin Roof Systems With Support + Third Point Bracing, Michael W. Seek

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

The Component Stiffness Method is a displacement compatibility method used to analyze C- and Z- section supported roof systems. The method provides a detailed analysis of the flexibility in the roof system and the distribution of forces as they flow out of the system. Parametric studies of the equations for typical roof systems have shown that by ignoring the flexibility of some of the components, the method can be simplified with little impact on the anchorage forces calculated. Changes have also been made to the way in which cross section deformations are incorporated into the method. This paper focuses on …

Effect Of Stressed-Skin Action On The Behaviour Of Cold-Formed Steel Portal Frames, A. M. Wrzesien, James B. P. Lim, R. M. Lawson

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

This paper describes six full-scale laboratory tests conducted on cold-formed steel portal frames buildings in order to investigate the effects of joint flexibility and stressed-skin diaphragm action. The frames used for the laboratory tests were of span of 6 m, height of 3 m and pitch of 10⁰; the frame spacing was 3 m. The laboratory test setup represented buildings of length of 9 m, having two gable frames and two internal frames. Tests were conducted on frames having two joint sizes, both with and without roof cladding. It was shown that as a result of stressed-skin diaphragm action, under …

Pull-Through Failure Tests Of Thin Steel Roof Battens Under Wind Uplift Loads, Mayooran Sivapathasundara, Mahen Mahendran

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

Thin profiled steel roof sheeting and battens are increasingly used in the construction of roofing systems of residential, commercial, industrial and farm buildings in Australia. The critical load combination of external wind suction and internal wind pressures that occur during high wind events such as thunderstorms and tropical cyclones often dislocate the roofing systems partially or even completely due to premature roof connection failures. Past wind damage investigations have shown that roof sheeting failures occurred at their screw connections to battens. In most of these cases, the screw fastener head pulled through the thin roof sheeting whilst the screw fasteners …

Development Of A Novel Pinned Connection For Cold-Formed Steel Trusses, Chris D. Mathieson, G. Charles Clifton, James B. P. Lim

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

Cold-formed steel trusses are a popular form of construction for light-weight buildings, particularly portal frame structures, for which spans up to 25m are increasingly common. In these long span trusses, providing high strength connections with sufficient elastic stiffness is a current limitation to developing cost-effective solutions. A novel pin-jointed truss connection named the Howick Rivet Connector (HRC) has been tested, firstly in a T-joint arrangement, then in a truss assemblage to determine its reliable strength and stiffness. Results showed that the HRC performs similarly to a bolted connection in terms of failure modes observed and loads reached. Additionally, the process …

Fragility Curves For Thin-Walled Cold-Formed Steel Wall Frames Affected By Ground Settlements Due To Land Subsidence, Luis A. Hernández-Castillo, Jose A. Ortiz-Lozano, Martin Hernández-Marín, Jesús Pacheco-Martínez, Mario E. Zermeño-Deleón, Juan J. Soto-Bernal, Jorge Ramos-Ruizflores, Miguel A. Soto-Zamora

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 results about a study regarding the performance of thin-walled cold-formed steel wall frames with different sheathing systems affected by angular distortions simulating ground differential settlements due to land subsidence. The wall frames are composed by vertical (studs) …

Experimental Seismic Behavior Of The Cfs-Nees Building: System-Level Performance Of A Full-Scale Two-Story Light Steel Framed Building, Kara D. Peterman, Rob L. Madsen, Benjamin W. Schafer

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

In the summer of 2013, testing of two full-scale cold-formed steel (CFS) framed buildings under seismic excitations took place at the Structural Engineering and Earthquake Simulation Lab (SEESL) at the University at Buffalo. Utilizing the twin shake tables, the two-story building specimens were subjected to ground motions from the 1994 Northridge earthquake. These experiments were conducted as a part of the CFS-NEES experimental effort in an attempt to advance cold-formed steel earthquake engineering and design. Two buildings were tested: the first, a specimen constructed with only structural components (CFS-framed gravity walls, shear walls, floor and roof diaphragms, with OSB sheathing …

Local Buckling Hysteretic Nonlinear Models For Cold-Formed Steel Axial Members, D. A. Padilla-Llano, C. D. Moen, M. R. Eatherton

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

This paper studies the energy dissipation and damage in thin walled members that experience local buckling and presents an approach to model cold-formed steel (CFS) axial members that experience local buckling deformations. The model is implemented in OpenSees using hysteretic models for CFS axial members calibrated using experimental responses. Results from thin-shell element simulations using ABAQUS show that energy dissipation in thin plates dissipates through inelastic strains and yielding that concentrates in damaged zones that extent approximately the length of a buckled half-wave (L_cr). Generally damage accumulates in one zone but when more than one damaged zone occurred …

Fire Resistance Prediction Of Load Bearing Cold-Formed Steel Walls Lined With Gypsum Composite Panels, Wei Chen, Jihong Ye

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

An innovative load-bearing cold-formed steel (CFS) wall lined with gypsum composite panels was developed with the goal of improving the construction efficiency and fire performance of these walls for applications in mid/high-rise buildings. The gypsum composite panel was formed by sandwiching insulation and plasterboard strips between two layers of gypsum plasterboards. Subsequently, the predicted fire resistance of these CFS walls was predicted based on our previously developed and experimentally validated modeling method. The degenerated material properties of the cold-formed steel and thermal physical property of the gypsum plasterboard and aluminum silicate wool were obtained from our pervious experimental investigations and …

Influence Of Diagonal Bracing Restraint On Cold-Formed Steel Perforated Columns Under Axial Compression, Chong Ren, Xianzhong Zhao

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

This paper presents a numerical investigation on the influence of diagonal bracing restraint on cold-formed steel perforated columns subjected to axial compression. Finite element method (FEM) is employed to analyse the structural behaviour of perforated columns. The results obtained from the present study highlight the influence of diagonal bracing restraint on post-buckling of columns, and the distortional-flexural mode interaction is also discussed. Furthermore, the accuracy of the present model is validated by comparing the results against the available experimental data.

Investigation On Seismic Performance Of Cold-Formed Steel Portal Frames, Yuanqi Li, Zhijian Xu, Yinglei Li, Yunfei Peng

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

A series of monotonous loading and hysteresis loading tests on cold-formed steel portal frames were conducted in this paper. The averaged ductility factor value of tested frames is 3.15 and the strength and stiffness degradation are not obvious during the test. The failure mode of frame is local buckling at column bases followed by local buckling at the top of columns, which lead to the dropping of frame’s load-carrying capacity. Then, the finite element model is developed and the analysis results match well with the test results. The research in this paper indicates that cold-formed steel portal frame has a …

Effect Of Stressed-Skin Action On Optimal Design Of A Cold-Formed Steel Portal Framing System, Duoc T. Phan, Andrzej M. Wrzesien, James B. P. Lim, Iman Hajirasouliha

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

Cold-formed steel portal frames can be a viable alternative to conventional hot-rolled steel portal frames. They are commonly used for low-rise commercial, light industrial and agricultural buildings. In this paper, the effect of semi-rigid joints and stressed-skin action are taken into account in the optimal design of cold-formed steel portal frames. A frame idealization is presented, the results of which are verified against full-scale. A real-coded niching genetic algorithm (RC-NGA) is then applied to search for the minimum cost for a building of span of 6 m, height-to-eaves of 3 m and length of 9 m, with a frame spacing …

Structural Strength Of Lapped Cold-Formed Steel Z-Shaped Purlin Connections With Vertical Slotted Holes, J. Liu, L. Xu, S. Fox

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

Lapped joints of cold-formed steel (CFS) Z-shaped purlins are extensively used in metal building roof systems. The research that has been carried out so far for these lapped connections is primarily focused on connections with round holes. However, the lapped connections with vertical slotted holes are extensively used in current construction practice to simplify the erection of continuous Z-shaped roof purlins. There are no design guidelines or recommendations available for CFS Z-purlin lapped connections with vertical slotted holes.

Presented in this paper are the results of an experimental study on the structural strength behaviour of lapped CFS Z-shaped purlin connections …

Direct Strength Method For Ultimate Strength Of Bolted Moment-Connections Between Cold-Formed Steel Channel Members, James B. P. Lim, Gregory J. Hancock, G. Charles Clifton, Cao Hung Pham

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

Experimental tests have previously shown that the strength of bolted moment-connections between cold-formed steel members, where the connections are formed through an array of bolts in the web, is dependent on the length of the bolt-group. This reduced strength has been observed in tests on portal frame joints as well as over-lapped purlin joints. For a short bolt-group length, in the order of the depth of the section, this paper shows that a reasonable lower bound to this reduced strength can be predicted by using the Direct Strength Method (DSM), modified to include the effect of the bimoment at the …

Towards Load-Deformation Models For Screw-Fastened Cold-Formed Steel-To-Steel Shear Connections, C. D. Moen, D. A. Padilla-Llano, S. Corner, C. Ding

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

This paper summarizes results from an experimental program considering single-fastened cold-formed steel-to-steel shear connections. Fastener motion (displacement and tilting angle) and bearing deformation occurring on the connecting members at the fastener location were captured using an automated, optical non-contact measurement procedure. The results are used to relate cold-formed steel-to-steel shear connection load-deformation response to tilting and bearing response. A general steel-to-steel single shear fastener load-deformation equation is also proposed and demonstrated.