Structural Engineering Commons^™

A Proposed Data Qualification Procedure For The Connecticut Bridge Monitoring Network, Stephen R. Prusaczyk

Master's Theses

No abstract provided.

Motivating Technical Writing Through Study Of The Environment, J. Linsdell, Thalia Anagnos

Faculty Publications

No abstract provided.

A Parametric Study Of Pedestrian Vertical Force Models For Dynamic Analysis Of Footbridges, Paul Archbold, Joe Keogh, Colin C. Caprani, Paul Fanning

Conference papers

Footbridge vibration has received much attention in recent years. However, stochastic models for crowd loading are not common, and estimation of crowd-induced vibration is typically done through enhancement factors applied to single pedestrian loading models. This work compares two such models, a moving force model and a spring-mass-damper model (SMD). Typical ranges for various pedestrian parameters are examined, and it is found that the pacing frequency has by far the greatest influence on bridge vibration response. It is also found that the magnitude of the response for pacing frequencies near the bridge natural frequency is lower for the SMD model, …

Modelling Of Highway Bridge Traffic Loading: Some Recent Advances, Bernard Enright, Colin C. Caprani, Eugene J. Obrien

Conference papers

The accurate estimation of site-specific lifetime extreme traffic load effects is an important element in the cost-effective assessment of bridges. In recent years, the improved quality and increasing use of weigh-in-motion technology has meant that better quality and larger databases of vehicle weights are now available. This has enabled measurements of the regular occurrence of extremely heavy vehicles, with weights in excess of 100 t. The collected measurements have been used as the basis for building and calibrating a Monte Carlo simulation model for bridge loading. The computer programs written to implement this model generate simulated traffic in two lanes …

Modeling Same-Direction Two-Lane Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright

Articles

Many highway bridges carry traffic in two same-direction lanes, and modeling the traffic loading on such bridges has been the subject of numerous studies. Different assumptions have been used to model multiple-presence loading events, particularly those featuring one truck in each lane. Using a database of weigh-in-motion measurements collected at two European sites for over 1 million trucks, this paper examines the relationships between adjacent vehicles in both lanes in terms of vehicle weights, speeds and inter-vehicle gaps. It is shown that there are various patterns of correlation, some of which are significant for bridge loading. A novel approach to …

Behaviour Of Unbonded Post- Tensioned Segmental Box Girders With Dry Joints, Michael Matson

Theses

The primary objective of this thesis is to examine the capacity of shear keys used in dry jointed precast post-tensioned segmental box girder bridge construction. The use of dry joints, in lieu of the more traditional glued joints, is becoming more popular in climatically suitable countries. The time and cost savings achieved using this construction form arc significant, due to the economies of scale involved.

The shear capacity of dry jointed keys is calculated using a number of available formulae. However, in previously published papers, significant differences have been noted in the results obtained from these formulae, deeming further investigation …

Bond Behavior Of Fiber Reinforced Polymer Bars Under Hinged Beam Conditions, Ryan James Sandstrom

Master's Theses

The research provided in this report examines the behavior of fiber reinforced polymer (FRP) reinforcing bars, embedded in normal weight concrete (NWC) hinged beam-end specimens, tested in accordance with two laboratory conditions. Reinforcing bars of different diameter, material configuration, and finished surface preparation were tested for bond strength parameters determined in accordance with ACI Committee Report 440.3. Bond strength parameters under the first condition were tested within NWC beams at a relatively low compressive strength and minimum embedment length; the second condition allowed testing within NWC beams at twice the design compressive strength of the first condition and moderate embedment …

Rubble-Mound Structure Design In The Coastal Environment, Jack Murphy

Theses

The main aims of this thesis were to investigate the main aspects of the design and implementation of rubble-mound structures as a form of shoreline stabilisation and coastal defence. An emphasis has been placed on the Irish context of how these structures have been implemented in the past. The intention was that this work would improve the understanding of the use of these structures for future projects both in Ireland and internationally.

This work required a literature review which investigated the general aspects of rubble-mound structures, the coastal environment, and the theory of designing the structures’ layout, cross-section and impact …

Characteristic Vertical Response Of A Footbridge Due To Crowd Loading, Colin C, Caprani, Joe Keogh, Paul Archbold, Paul Fanning

Conference papers

The characteristic vertical vibration of a flexible footbridge subject to crowd loading is examined in this paper. Typically, bridge vibrations produced from a crowd of pedestrians are estimated by using an enhancement factor applied to the effect caused by a single pedestrian. In this paper, a single pedestrian model, represented by a spring mass damper, which incorporates variables such as pedestrian mass and body stiffness, is used to calibrate a computationally efficient moving force model. This calibrated moving force model is further used in Monte Carlo simulations of non-homogenous crowds to estimate characteristic vertical vibration levels. Enhancement factors, which could …

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 …

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.

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 …

Experimental Investigation Of Optimized Cold-Formed Steel Compression Members, D. J. Klingshirn, E. A. Sumner, N. A. Rahman

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

In the past, standard C - shaped metal studs have been the only option for designers and contractors when selecting a cross section for load bearing compression members. T he sigma shaped section has recently emerged as an alternative to the C - section. The sigma shaped section is very similar to the C - shape, with the exception of having an intermediate web return and complex stiffeners. The experimental results of concentric axial compression tests of fifty - eight sigma shaped members are reported. Specimen s were tested at various lengths to force global, distortional, and local buckling failure …

Comparative Behavior Of Built-Up Cold-Formed Box Sections Under Rigid And Flexible End Support Conditions, W. Reyes, F. A. Guzman

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

According to section D1.2 of AISI S100-2007 for compression members composed of two sections in contact whose buckling mode involves shear forces in the connectors, a reduction must be made, KL r ⁄ must be replaced by ሺ KL r ⁄ሻ ୫ . This new modified slenderness ratio takes into account the connection weld spacing and the minimum radius of gyration of an individual shape in the built-up member. Under the provisions of section D1.2 a reduction in load capacity must be made for built-up welded box members, which are the subject of this study. An experimental investigation on 48 …

Theoretical Analysis Of Cold-Formed Steel Battened Double Angle Members Under Compression, W. F. Maia, J. Munaiar Neto, M. Malite

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

In Brazil, battened double angle system is one of the systems most used in light truss, however, there are not any specific studies on its behavior, resulting in the fact that the standard procedures do not provide subsidies for the design of this section. Moreover, cold-formed steel si mple angles under compression, mostly with slender legs, have an interesting structural behavior compared to other cold-formed steel shapes. Two critical modes are observed in the elastic stability analysis: (i) global flexural mode in the case of longer members and (ii) a coincident local-plate/global flexural-torsional mode, which is critical for shorter members. …

Direct Strength Design Of Cold-Formed C-Sections For Shear, Cao Hung Pham, Gregory J. Hancock

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

The Direct Strength Method (DSM) rece ntly included in the North American Specification and Australian/New Zealand Standard AS/NZS 4600:2005 gives design rules for compression and bending. No rules are presente d at this stage for shear. Two series of tests on C-section can be used to develop and calibrate rules for design in shear. These are the University of Missouri Rolla tests of the 1970’s and recent tests on high strength C-sections at the University of Sydney. Both series of tests use a similar test rig altho ugh different levels of tension field action have been observed. Two features research …