Structural Engineering Commons^™

Modeling Extreme Traffic Loading On Bridges Using Kernel Density Estimators, Cathal Leahy, Eugene J. Obrien, Bernard Enright

Conference papers

Kernel density estimators are a non-parametric method of estimating the probability density function of sample data. In this paper, the method is applied to find characteristic maximum daily truck weights on highway bridges. The results are then compared with the conventional approach

High-Strength Selfconsolidating Concrete Girders Subjected To Elevated Compressive Fiber Stresses, Part 2: Structural Behavior, Jared E. Brewe, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The design of prestressed concrete members is restricted by the requirement that the extreme compressive fiber stress at midspan be less than 60% of the concrete compressive strength at release of prestressing. the purported purpose of this limit is to provide serviceability performance, but it places unnecessary limits on the capability of the materials. for this research program, six prestressed concrete girders were produced with high-strength, self-consolidating concrete and subjected to elevated compressive fiber stress levels ranging from 65% to 84% of initial concrete compressive strength at release of prestressing. Part 1 of this series analyzed time-dependent prestress losses and …

A Wireless System For Crack Monitoring In Concrete Structures, Souhail M. Saad

Dissertations and Theses @ UNI

The formation of cracks in concrete is a normal phenomenon. However, effective control and prevention of the formation of cracks is the key for successful life of concrete structures. Specifically, cracks represent a path of least resistance for moisture and corrosive ionic agents from de-icing salts to reach embedded steel in concrete. Commercial wireless sensor networks utilizing crack gauge sensors can be applied for crack monitoring in the common concrete structure. The crack sensors circuits' boards, which are used to stimulate the cracks, are currently unavailable for the SG-Link module platform.

The SG-Link module is an ultra-low-power module for use …

Investigating Wood Welding Parameters Using A Prototype Welding Machine, Timothy R. Melin

Master's Theses

Understanding how different processing variables influence wood welded bonds is vital if the technique will ever be used to create engineered lumber without using adhesives. A variation of vibration welding, wood welding uses pressure and friction to bond materials together. During welding, heat causes a softening in the wood, a naturally occurring composite material. This softening leads to fiber entanglement and a bond forms upon cooling.

The goal of this research was to investigate several processing aspects of the wood welding procedure. A prototype wood welding machine, designed and fabricated from the ground up, was used to investigate the effects …

Product Technical Information, Steel Stud Manufacturers Association

CCFSS Library (1939 - present)

No abstract provided.

Cold-Formed Steel Framing Seismic Design Optimization Phase 1a: Seismic Equivalency Parameter Evaluation, American Iron And Steel Institute

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

No abstract provided.

A Life-Cycle Assessment Of Cold-Formed Steel Enclosures Verses Alternative Enclosures In Commerical Buildings, K. J. Van, L. Xu

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

In North America, the operation of buildings accounts for approximately one third of the total energy use and greenhouse gas emissions each year. Over the life of a building, the total energy use is a combination of the embodied energy in the building materials and the operating energy of the building. Building enclosures (walls and roofs) have a huge impact on both the embodied energy and the operating energy of buildings. Historically, steel has been blacklisted as a material with a high embodied energy. This has led to a misconception that steel enclosures use significantly more energy than other enclosure …

Behavior And Design Of Axially Compressed Sheathed Wall Studs, L. C. M. Vieira Jr., B. W. Schafer

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

The objective of this paper is to summarize efforts in a multi year project dedicated to developing a reliable design method for cold - formed steel wall studs that rely on sheathing for bracing. Testing on single columns with sheathing, and full - scale walls with sheathin g, are summarized. Particular emphasis is placed on the observed limit states given the different sheathing conditions. The sheathing supplies beneficial restraint to the wall studs and the stiffness of this sheathing - based restraint is characterized exper imentally and analytically. A unique application of the Direct Strength Method of design is explored …

Lateral Torsional Instability Of Single Channels Restrained By Angle Cleats, G. M. Bukasa, M. Dundu Masce

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

A series of experiments on the lateral tors ional instability of single channels is presented. The channels are restrained by a purlin – angle cleat connection and subjected to a two point loading system in order to simulate a distributed load. Failure of the channels occurred by local buckling of the compression zone of the flange and web and lateral torsional buckling of the channels between points of lateral support. Tests have shown the purlin–angle cleat connection to be capable of restraining the frames from failing due to lateral-torsional buckling. This eliminates the idea of having fly-bracings, which is normally …

Extending Direct Strength Design To Cold-Formed Steel Beams With Holes, Christopher D. Moen, Benjamin W. Schafer

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

The extension of the American Iron and Steel Institute’s Direct Strength Method (DSM) to cold-formed steel beams with holes is nearly in place. DSM was first introduced to th e AISI specification in 2004 as an alternative to the effective width met hod, and is widely considered a major advancement in cold-formed steel component design. In DSM, the beam elastic buckling properties for a general cross-section are obtained with a computer analysis utilizing the finite strip method. A disadvantage of the finite strip method and DSM has been that discrete holes along the member length could not be easily accounted …

Load-Carrying Capacity Estimation On Cold-Formed Thin-Walled Steel Columns With Built-Up Box Section, Yuangqi Li, Xingyou Yao, Zuyan Shen, Rongkui Ma

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

The use of cold-formed thin-walled steel structural members has increased in recent years, and most of their sections are open section with only one symmetrical axis, which would likely fail by twisting and interaction with the others buckling mode, such as local buckling and distortional buckling. To improve the ultimate strength of columns, built-up box section can be used. In this paper, a series of loading capacity tests on high-strength cold- formed steel columns with built-up bo x section are presented, including 21 axially-compressed columns and 19 eccentrically-compressed columns sub- jected to bending moments about weak axis as well as …

Flexural And Cyclic Behaviour Of Hollow And Concrete-Filled Steel Tubes, S. Arivalagan, S. Kandasamy

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

This paper presents a study on the flexural and cyclic behaviour of concrete filled steel hollow beam sections. The specimens in-filled with normal mix concrete, fly ash concrete, quarry waste concrete and low strength concrete (Brick-bat-lime concrete) and hollow steel sections were tested. Measurements of strains and deflections were made under two-point loading. A theoretical model was also developed to predict the moment carrying capacity. The capacities of the beams were compared with the ultimate capacity obtained using the international standards EC4-1994, ACI-2002 and AISC-LRFD-1999. The result of the experimental investigation showed that the moment carrying capacity increases based on …

Angle Cleat Base Connections, M. Dundu, S. Maphosa

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

Tests, performed on base connections fabricated from cold-formed channels and hot-rolled angle cleats, are presented in this paper. This research is part of an on- going research to develop portal frames made out of cold-formed steel. The base connections are subjected to an axial load and moment. Hot-rolled angle cleats are used to prevent premature failing of the base connections. Several loading configurations are considered and these are dependent on the eccentricity of the load. In all the tests the cold-formed channels failed by local buckling. A significant amount of bearing distortion was observed in the heavily loaded flange. The …

Some Aspects On Seismic Design On Frames Designed With Cold Formed Steel Shapes, Gabriel Valencia

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

The response of cold-formed steel structures to seismic excitations is not the same as that of structures designed with rolled shapes, in fact, the seismic design codes require that the shapes, meet minimum width/thickness ratios, which virtually no commercial cold formed steel shapes meet, so the design of structures with these elements is excluded from those codes. Different types of beam- to -column connections, made using cold-formed steel shapes have been tested, in order to establish their response to cyclic loads of increasing magnitude. The analysis of these connections using theoretical models with Finite Element Analysis (FEA), and through monotonic …

Evaluating The Lrfd Factor For Cold-Formed Steel Compression Members, Karthik Ganesan, Christopher D. Moen

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

This paper summarizes recent work to determine if the LRFD resistance factor for cold-formed steel compression member s can be increased above its current value of φ c =0.85. An experimental database of 675 concentrically loaded columns with plain and lipped C-sections, plain and lipped Z-sections, hat sections and angle sections, including members with holes was compiled. The predicted strength of each specimen was calculated with the AISI-S100-07 Main Specification and Direct Strength Method (DSM). Test-to-predicted strength statistics were employed with the first order second moment reliability approach in AISI-S100-07 Chapter F to calculate the resistance factors. The observed trends …

The 2008 Aisi Cold-Formed Steel Design Manual, Richard C. Kaehler, Helen Chen

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

The 2008 edition of the AISI Cold-Formed Steel Design Manual has been published. The new edition includes updated examples and design aids as well as newly developed example problems and design aids covering new material in the 2007 edition of the North American Specification for the Design of Cold-Formed Steel Structural Members . Also included are all current AI SI structural Test Standards.

Performance Of Knee-Braced Cold-Formed Steel Shear Walls Subjected To Lateral Cyclic Loading, Mehran Zeynalian Dastjerdi, Hamid Reza Ronagh

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

Light weight Steel Framed structures currently in use in Australia, are normally braced using face mounted thin straps, cross braces that are of the same shape as studs, or compressed cement boards screwed to the face of the walls. While these are found adequate in low seismic regions of Australia, an investigation into the earthquake resistance properties of LSF have led authors to investigate alternative bracing types that may present a more favourable ductility. Knee braces that are specially designed for this purpose are introduced in the paper and studied in a specially designed testing rig. The tests are on …

Buckling Analysis Of Cold-Formed Steel Members With General Boundary Conditions Using Cufsm Conventional And Constrained Finite Strip Methods, Z. Li, B. W. Schafer

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

The objective of this paper is to provide the theoretical background and illustrative examples for elastic buckling analysis of cold-formed steel members with general boundary conditions as implemented in the forthcoming update to CUFSM. CUFSM is an open source finite strip elastic stability analysis program freely distributed by the senior author. Although the finite strip method presents a general methodology, the conventional implementation (e.g. CUFSM v 3.13 or earlier) employs only simply-supported boundary conditions. In this paper, utilizing specially selected longitudinal shape functions, the conventional finite strip method is extended to general boundary conditions, including the conventional case: simply-simply supported, …

Arc-Spot Welds For Multi-Overlap Roof Deck Panels, N. Guenfoud, R. Tremblay, C. A. Rogers

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

Roof deck construction often incorporates cold-formed steel panels that are connected to the underlying framing with the use of arc-spot welds. The welds are commonly located in areas where multiple layers of roof deck exist, such as at sidelaps or endlaps. CSA S136 restricts the use of multi-layer connections to being less than 2.5 mm thick; as well, the thickness of the supporting steel must exceed 2.5 times the aggregate thickness of the deck. In effect, the standard does not allow for the use of arc-spot welds for 18 ga (1.21 mm) and 16 ga (1.52 mm) roof deck panels. …

Cyclic Elastoplastic Large Displacement Analysis Of Cold-Formed Steel Box Columns Under Combined Action Of Axial And Bidirectional Lateral Loading, Iraj H. P. Mamaghani, Saman Montazeri

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

This paper deals with the cyclic elastoplastic large displacement analysis of cold-formed steel box columns under combined action of axial and bidirectional lateral loading. Cold-formed steel box columns are very useful in highway bridge pier construction as they offer flexible space requirement and provide speedy construction. Behavior of cold-formed steel box columns under earthquake-induced loads is rather complicated as earthquakes occur in an oblique direction. However, modern seismic design philosophies have been based on the behavior of structures under independent actions of uni-directional loading in orthogonal directions. In this study, inelastic cyclic behavior of steel columns subjected to constant axial …