Engineering Commons^™

The Strength Of Partially Stiffened Stainless Steel Compression Members, W. Reyneke, G. J. Van Den Berg

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

In this study the effect of the non-linear behaviour of stainless steels on the local buckling strength of partially stiffened compression elements is studied. The steel under investigation is a Type 304 stainless steel. Doubly symmetric hat section columns were manufactured by a press braking process and tested as stub columns to exclude overall buckling interaction. The different plasticity reduction factors' suggested in the ASCE stainless steel design specification for stiffened and unstiffened compression elements are used to compare experimental results with theoretical predictions. It is concluded that the ASCE and South African stainless steel design specifications overestimate the local …

Effective Width Of A Simple Edge-Stiffener Subjected To A Stress Gradient, Colin A. Rogers, R. M. Schuster

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

The most recent editions of the North American Design Standards present a unified effective width approach for the design of compressive elements. This paper outlines a comparison of various modifications to the existing procedure used to calculate the effective width of a simple edge-stiffener subjected to a stress gradient. The comparison involves three methods where the magnitude of the compressive stress is altered, and two stress gradient methods where the plate bucking coefficient is based on the ratio of compressive stresses at the top and bottom of the flat width of the simple edge-stiffener. Analysis of these methods was carried …

The Effects Of Perforation Length On The Behaviour Of Perforated Elements In Compression, J. Rhodes, M. Macdonald

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

The compressional behaviour of stub columns having perforations in the form of slots of different length is examined on the basis of testing. Plain channels of a specified geometry are considered, and the geometry examined follows that of a test programme previously carried out to examine the effects of perforation location on stub column strength. Two different perforation layouts, and two material thicknesses are considered and systematic variation in the slot length is carried out for each layout and thickness. It is found that the stub column compression capacity reduces as the perforation length increases. The test results are compared …

Recent Research And Developments In Cold-Formed Steel Design And Construction, Roger A. Laboube, Wei-Wen Yu

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

Golden Anniversary of the AISI Specification - The 1996 AISI Specification - A New AISI Cold-Formed Steel Design Manual - Design of Cold-Formed Steel Stiffened Elements with Multiple Longitudinal Intermediate Stiffeners - A Probablistic Examination of the Ultimate Strength of Cold-Formed Steel Elements - Effective Width of a Simple Edge-Stiffener Subjected to Stress Gradient - The Effects of Perforation Length on the Behaviour of Perforated Elements in Compression - Interaction of Flangel/Edge-Stiffened Cold-Formed Steel C-Sections - Cold-Formed Steel Flat Width Ratio Limits, d/t and d/w - Comparison of the Distortional Buckling Method for Flexural Members with Tests - Design of …

Design Of Cold-Formed Steel Stiffened Elements With Multiple Longitudinal Intermediate Stiffeners, Benjamin W. Schafer, Teoman Pekoz

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

Current specification procedures for calculating the bending strength of members with multiple longitudinal intermediate stiffeners in the compression flange have been found to be inadequate. A new procedure for calculating the effective width of stiffened elements with multiple intermediate stiffeners is presented. The new method introduces the calculation of a buckling coefficient for overall buckling of the entire stiffened element as a unit, and local buckling of the subelement plates between stiffeners. The expression for calculating overall buckling is derived and verified via comparison to numerical methods. The minimum buckling coefficient from the two modes (local and overall) is used …

Cold-Formed Steel Design By Spreadsheet Program, Scott A. Burns

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

This paper demonstrates how to use advanced features of a spreadsheet program to design cold-formed steel members efficiently. The example presented in the paper concerns a hat section in flexure which is to be designed for maximum bending strength with a restriction on the total amount of steel that can be used. The nature of the formulas and data entered into the spreadsheet program are presented.

Evaluation And Modelling Of The Material Properties For Analysis Of Cold-Formed Steel Sections, Nabil Abdel-Rahman, K. S. Sivakumaran

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

The results of two series of experimental investigations to evaluate the mechanical properties and the residual stresses of cold-formed steel (CFS) sections are reported in this paper. These investigations were performed on channel-shaped CFS sections manufactured using cold-roll forming technique. Tensile coupon tests were used to evaluate the mechanical properties at different positions of the channel sections. Electrical resistance strain gauges with an "Electrical Discharge Machining" cutting technique were used to establish the magnitudes and the distributions of residual stresses within the channel sections. Based on the experimental results, appropriate analysis models for the stress-strain relationship, the variation of the …

The Modulus Of Elasticity Of Steel - Is It 200 Gpa?, Mahen Mahendran

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

In cold-formed steel construction, the use of a range of thin, high strength steels (0.35 mm thickness and 550 MPa yield stress) has increased significantly in recent times. A good knowledge of the basic mechanical properties of these steels is needed for a satisfactory use of them. In relation to the modulus of elasticity, the current practice is to assume it to be about 200 GPa for all steel grades. However, tensile tests of these steels have consistently shown that the modulus of elasticity varies with grade of steel and thickness. It was found that it increases to values as …

Design Of Thin-Walled Beams For Distortional Buckling, C. Jiang, J. Michael Davies

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

The bending behaviour of cold-formed steel beams is far from simple. The double symmetry associated with hot-rolled I-sections is generally uneconomical and the use of thin-walled slender elements means that local buckling of parts of the cross-section in compression may be a significant design factor leading to additional asymmetry of behaviour. Furthermore, the modern tendency to introduce additional folds in order to control local buckling and to produce more favourable global section properties also serves to aggravate the tendency towards distortional buckling. Generalised Beam Theory (GBT) has wide application to the analysis and design of cold-formed beams and can provide …

Buckling Experiments On Hollow Flange Beams With Web Stiffeners, Mahen Mahendran, P. Avery

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

A new cold-formed and resistance welded section known as the Hollow Flange Beam (HFB) has been developed recently in Australia. In contrast to the common lateral torsional buckling mode of I-beams, this unique section comprising two stiff triangular flanges and a slender web is susceptible to a lateral distortional buckling mode of failure involving lateral deflection, twist and cross-section change due to web distortion. This lateral distortional buckling behaviour has been shown to cause significant reduction of the available flexural strength of HFBs. An investigation using finite element analyses and large scale experiments was carried out into the use of …

Deflection Design Of Cold-Formed Rhs Steel Beams, Xiao-Ling Zhao, Kwong-Ping Kiew

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

The moment-deflection results of cold-formed RHS (rectangular hollow section) steel beams are examined. A simple design approach is proposed to account for the effect that material nonlinearity has on deflection. A general expression is also derived to predict the deflection of cold-formed RHS steel beams.

Determination Of Purlin R-Factors Using A Non-Linear Analysis, Catherine J. Rousch, Gregory J. Hancock

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

In both Australia and the U.S.A., the design procedure for purlins under wind uplift loading is based on the use of reduction factors (R-factors), which allow for the flexural-torsional or nonlinear twisting behaviour of purlins with screw-fastened sheeting. To date, all R-factors have been determined by testing. However, in the future it may be more efficient to obtain R-factors from numerical models to minimise testing. This paper shows how a numerical model of the twisting behaviour of channel and Z-section purlins can be used to generate R-factors. Comparisons between experimentally determined and numerically based R-factors are made.

Experimental Research On The Behaviour Of Combined Web Crippling And Bending Of Steel Deck Sections, J. G. M. Kerstens, H. H. Snijder, Monique Bakker, H. Hofmeyer

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

At an interior support, sections of cold-formed steel are subjected to a concentrated load and a bending moment Existing design rules describing the section failure at an interior support are subject to improvement and are not based on the section's physical failure behaviour. In the last decade, several analytical models have been developed that predict the section ultimate concentrated load and directly include the influence of the bending moment, so that an empirical interaction method is not needed. However, the authors believe that these models are correct only for a concentrated load and a small bending moment In practice large …

Flexural Strength Of Cold-Formed Steel Panels Using Structural Grade 80 Of A653 Steel, Shaojie Wu, Wei-Wen Yu, Roger A. Laboube

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

Cold-formed steel decks made of the Structural Grade 80 of ASTM A653 steel (formerly ASTM A446 Grade E steel) are currently designed according to the AlSI specification, using 75% of the specified minimum yield strength of the steel or 60 ksi (413.7 MPa), whichever is less, due to the lack of ductility of the steel. To further evaluate the flexural strength of the cold-formed steel decks using such a steel, a total of seventy-two deck panels with hat-shaped sections were designed and tested under simply supported and two-point loading condition. The test results indicated that for the panel specimens with …

Dynamic Performance Of Light Gauge Steel Framed Shear Walls, Reynaud Serrette, Georgi Hall, Hoang Nguyen

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

The results of a series of reversed cyclic 4 ft. x 8 ft. (length x height) 15/32-in. plywood and 7/16-in. oriented strand board (OSB) shear wall tests are presented in this paper. The walls were framed with C-shaped 3-1/2 in. 20 gauge (0.036 in.) studs at 24 in. on center. Each wall was subjected to a sequential phase displacement time history at a frequency of 0.67 Hz. Performance of the wall was shown to depend on the type of sheathing material, the strength of the chord studs, and the screw fastener schedule. Although the hysteretic loops were significantly pinched (a …

Stability Of Standing Seam Roof - Purlin Systems, James M. Fisher, Joe N. Nunnery

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

Presented in this paper are the design considerations of purlins which support standing seam roofs. To properly design purlins attached to standing seam roofs the AISI Base Test must be conducted. The AISI anchorage equations can be used for standing seam systems provided that it can be shown that the standing seam diaphragm system has sufficient stiffness to meet the requirements of the diaphragm as specified in Section D3.2.1 of the AISI Specification. The stiffness of standing seam roofs can be determined from conventional diaphragm tests. The stiffness and strength of the standing seam diaphragm can be enhanced by the …

Proceedings: Seventeenth Vertebrate Pest Conference, Rohnert Park, California, March 5-7, 1996 (Complete Work), Robert M. Timm , Editor, A. Charles Crabb , Editor

Vertebrate Pest Conference Proceedings: 17th (1996)

340 registered attendees
58 papers
273 pages
52 Mb

You have come from throughout California, from across the United States, and from many corners of the world to gather here for the purpose of sharing information, expertise, and wisdom in dealing with vertebrate pest problems. Our common purpose is to find yet better methods for preventing and resolving situations in which wildlife comes into conflict with humans. The Conference's mission remains one of education. We learn from each other, and we strive to find better ways of applying our knowledge to real-world problems.

Disaccharide Intolerance Of European Starlings, Leonard R. Askham

Vertebrate Pest Conference Proceedings: 17th (1996)

The use of disaccharides to discourage bird depredation to agricultural crops has elicited some interest during the last few years. Data developed in these trials indicate that several avian species are intolerant to sucrose because of the lack of sucrase enzymes in their digestive systems. Based on this research it is hypothesized that progressively increasing rates and volumes of solutions would elicit consistent adverse stress reactions. Furthermore, that if birds were intolerant to sucrose, because of their co-evolutionary development with plants, then they should lack the ability to digest lactose. The data developed in these trials does not support either …

Closing Remarks—Seventeenth Vertebrate Pest Conference, Rex O. Baker

Vertebrate Pest Conference Proceedings: 17th (1996)

As chair-elect of the council, I would like to thank all of those who participated in this 17th Vertebrate Pest Conference.

We had a total attendance of 340 from 27 states in the U.S., including 27 attendees from 8 countries outside the U.S. The contributions and sacrifices made by foreign speakers is genuinely appreciated and has, as always, added greatly to the diversity of the conference.

As most of you know, the council's primary goal is fostering education and advancement in the field of vertebrate pest management. We have always tried to draw noted experts to present a broad range …

Field Efficacy Of Diphacinone Grain Baits Used To Control The California Ground Squirrel, J. A. Baroch

Vertebrate Pest Conference Proceedings: 17th (1996)

Diphacinone treated oat groats were effective in reducing populations of California ground squirrels (Spermophilus beecheyi) by more than 84%. Two concentrations of active ingredient (0.005% and 0.01%) were compared, as well as two application methods: spot baiting and bait stations. Squirrel activity on test plots was assessed before and after bait applications using visual counts and active burrow counts. There was good correspondence between results of the two activity indices. There was no significant improvement in efficacy provided by the higher concentration of diphacinone. Bait consumption was much lower on bait station plots. Squirrel carcasses were found on …

Overhead Wires Reduce Roof-Nesting By Ring-Billed Gulls And Herring Gulls, Jerrold L. Belant, Sheri K. Ickes

Vertebrate Pest Conference Proceedings: 17th (1996)

The authors evaluated the effectiveness of overhead wires in reducing roof-nesting by ring-billed gulls (Larus delawarensis) and herring gulls (L. argentatus) at a 7.2 ha food warehouse in Bedford Heights, Ohio during 1994-1995. In 1994, stainless steel wires (0.8 mm diameter) were attached generally in spoke-like configurations between 2.4 m upright metal poles spaced at 33.7 m intervals over the main portion of roof. The 6 to 14 wires radiating from each pole created a mean maximum spacing between wires of about 16 m. Nesting by ring-billed and herring gulls was reduced by 76% and 100% …

Towards "Best Practice" Vertebrate Pest Management In Australia, Mike Braysher, Peter O'Brien, Mary Bomford

Vertebrate Pest Conference Proceedings: 17th (1996)

Australia has 26 species of introduced pest mammals that cause extensive damage to agriculture and the conservation of native wildlife. Past efforts tried to eradicate them. This focus on reducing pest numbers rather than the outcome, reduced damage, has had limited success. Under its Vertebrate Pest Program, the Bureau of Resource Sciences has developed principles and a strategic approach to managing pest damage. Close cooperation with land managers as co-researchers and co-learners is an essential element, as is a coordinated group approach to pest management. The approaches are illustrated with an example.

Effectiveness Of Vichos Non-Lethal Collars In Deterring Coyote Attacks On Sheep, J. Russell Mason, Richard J. Burns

Vertebrate Pest Conference Proceedings: 17th (1996)

Vichos non-lethal collars containing 45 to 105 ml of 3 % capsicum oleo resin were evaluated as deterrents to coyote attacks on sheep. Each of five coyotes tested made neck/throat attacks on one collared lamb; four punctured collars and one pulled the collar from a lamb without puncturing it. One coyote did not resume biting the lamb for 60 min; it was retested two and four days later. At two days, the coyote punctured a second collar and briefly halted its attack. At four days, the coyote attacked a third collared lamb but made no attempt to grasp the neck/throat …

An Overview Of Animal Damage Control (Adc) Assistance To The Vertebrate Pest Management Industry, William H. Clay

Vertebrate Pest Conference Proceedings: 17th (1996)

The Animal Damage Control (ADC) program has had a long history dating back to 1885. ADC was officially established in 1931 under the United States Department of Agriculture. In 1939, the program was moved to the United States Department of Interior's Fish and Wildlife Service. In 1996, ADC was transferred back to the USDA and placed under the Animal and Plant Health Inspection Service. The mission of the Animal Damage Control program is to provide federal leadership in managing problems caused by wildlife. Current program assistance includes: a) technical assistance in wildlife management; b) conducting research and development activities related …

Improved Sealants For M-44 Cyanide Capsules, Guy Connolly

Vertebrate Pest Conference Proceedings: 17th (1996)

The M-44 sodium cyanide ejector is one of the most important tools used by the Animal Damage Control (ADC) program to protect livestock from coyotes. Unacceptable performance of M-44 cyanide capsules due to inadequate seals stimulated research to develop a better capsule sealant. Comparative tests of crude beeswax, Scheel SC-100 wax, and other materials revealed that capsules sealed with SC-100 were most resistant to deterioration in adverse environments. Based on these results, SC-100 wax was selected as the sealant of choice. Beginning in April 1989, all M-44 capsules made for ADC program use have been sealed with SC-100 wax. Since …

Impacts Of A Daily Trap Check Law On The California Adc Program, Craig Coolahan

Vertebrate Pest Conference Proceedings: 17th (1996)

Effective January 1, 1990 California law required that all steel-jawed leghold traps be inspected at least daily and all animals in such traps be removed. The inspection and removal could be performed by the individual who set the traps, the landowner, or an agent of either. Prior to the passage of this law, California Animal Damage Control (ADC) personnel were exempt from Department of Fish and Game trap checking regulations. The data suggest that a decrease in trap use occurred after the implementation of the daily trap check. Where the program could effectively substitute other control tools or methods for …

Analysis Of Vertebrate Pest Research, Jim Hone

Vertebrate Pest Conference Proceedings: 17th (1996)

Research on vertebrate pest control is mostly empirical, focusing on control of species X in location Y using method Z. Such an approach is needed. The science of vertebrate pest research is developing some generalizations across species, locations, and methods. This paper further explores such generalizations by discussing six questions asked by Hone (1994), the answers to which are relevant to vertebrate pest research world-wide. Several case studies are examined, with emphasis on control of damage by small mammals and predation control. Suggestions are made for future research.

Operational Control Of The Brown Tree Snake On Guam, Thomas C. Hall

Vertebrate Pest Conference Proceedings: 17th (1996)

An operational control program for brown tree snakes (Boiga irregularis) on Guam began in April 1993. The program focused on minimizing the dispersal of brown tree snakes to other Pacific islands and the U.S. mainland. During the first year of operation, more than 3,000 snakes were caught within a kilometer of high risk port facilities using traps, detector dogs, and spotlighting. Additionally, habitat modifications and prey-base removal were used to reduce the attractiveness of these facilities to brown tree snakes. Public awareness was also an important part of the program such as the education of cargo packers, shippers, …

Rodents And Cover Crops—A Review, Gregory A. Giusti, Desley A. Whisson, W. Paul Gorenzel

Vertebrate Pest Conference Proceedings: 17th (1996)

Inter-row plantings of herbaceous cover crops has become a widely accepted practice by orchard and vineyard managers. Cover crops, used as part of a production management system, are not considered a cash crop and are therefore selected by individual growers for various reasons. Little is written regarding the relationship of cover crop management and the impact on rodent populations. This paper reviews the recent literature and examines how cover crop species and cultivar selection along with management procedures may be influential in limiting rodent populations and their damage to cropping systems.

A Profile Of Depredating Mountain Lions, Steven D. Fairaizl, San Juan Stiver

Vertebrate Pest Conference Proceedings: 17th (1996)

Information regarding the demographics and physical condition of mountain lions (Felis concolof) killed during damage control efforts in Nevada was gathered and compared to sport harvested mountain lions. The average age of depredating male lions was 4.92 years of age compared to 4.95 years for sport harvested males. Depredating female lions were older than sport harvested females averaging 5.09 years compared to 4.44 years. Older age class mountain lions of both sexes were more likely to commit depredations than expected. Male lions were involved in depredations 45 % more often than females. Domestic sheep comprise more than 90% …