Limit states design of HSS columns

1979 ◽  
Vol 6 (2) ◽  
pp. 276-291 ◽  
Author(s):  
Reidar Bjorhovde ◽  
Peter C. Birkemoe
Keyword(s):  
Column Tests ◽  
Limit States ◽  
Corrosion Stability ◽  
Production Methods ◽  
Design Procedures ◽  
Heat Treated ◽  
Compression Members ◽  
Hollow Structural Sections ◽  
Experimental And Theoretical Studies ◽  
Better Than

Hollow structural sections (HSS) have come into increasing usage for structural purposes over the past number of years. There are several reasons for this development, in particular, the advantages of such shapes from an architectural viewpoint, the strength inherent in a closed cross section, corrosion stability, and ease of maintenance. Due to their shape, the members are particularly suited for use as columns.This paper presents a review of typical HSS production methods used throughout the world today, with emphasis on the effect of several important parameters that vary with the production process. Following a general discussion of column strength theory and its application to HSS columns, the development of limit states design procedures for compression members is evaluated. Special attention is paid to the requirements of the standard CSA S16.1-1974, and the studies that led to these rules.Outlining briefly the philosophy of full-scale column testing and typical procedures that are followed in such work, the ensuing portions of the paper present detailed data from experimental and theoretical studies on Canadian-produced HSS sections. Column tests conducted on heat-treated shapes are compared to other data from similar tests on columns produced by a variety of manufacturing processes. It was generally found that the heat-treated shapes performed somewhat better than the cold-formed columns, considered as a whole, and that within the cold-formed data there was considerable variation between manufacturers. Comparison with data from column tests conducted in Japan and in Europe revealed that the Canadian shapes tended to fall within the upper portions of the data band.In closing, preliminary recommendations are presented for the evaluation of the strength of various manufactured HSS members in limit states design.

Design examples for HSS trusses

1986 ◽  
Vol 13 (4) ◽  
pp. 460-473 ◽  
Author(s):  
Jeffrey A. Packer
Keyword(s):  
Welded Joints ◽  
Design Method ◽  
Limit States ◽  
International Consensus ◽  
Hollow Section ◽  
Design Procedures ◽  
Complex Design ◽  
Structural Engineers ◽  
Hollow Structural Section ◽  
Hollow Structural Sections

Following recent international consensus on a series of complex design formulae for the static strength of welded joints in hollow structural section (HSS) trusses, design aids and design procedures compatible with CAN3-S16.1-M84 and based on these recommendations have been produced for implementation in Canada. This paper formally illustrates the use of these design aids by undertaking design examples for rectangular hollow section (RHS) chord planar trusses. The design aids discussed by the writer are in the form of charts for manual design and an interactive microcomputer program for automated truss design. Although the design method is much more rigorous than that presently used by Canadian structural engineers, who typically follow the guidelines of the Stelco HSS connections manuals, it vividly illustrates to the user the principal parameters affecting the strength of welded joints in HSS trusses. The paper also demonstrates that the joint strength criteria frequently control the selection of members, thereby making the design and checking of such joints the responsibility of the design engineer rather than the fabricator. Key words: hollow structural sections, tubes, welded joints, trusses, limit states design, design aids.

Study on the Organization and Mechanical Properties of Q345R Weld-Joint

2012 ◽  
Vol 562-564 ◽  
pp. 573-577
Author(s):  
Xiao Dong Hu ◽  
Yong Zhang ◽  
Jian Tao Lv ◽  
Sen Zhang
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Weld Seam ◽  
Weld Zone ◽  
Submerged Arc Welding ◽  
Butt Weld ◽  
Heat Treated ◽  
Metallurgical Structure ◽  
Submerged Arc ◽  
Better Than

The butt weld of Q345R with the thickness of 40mm has been manufactured with the submerged-arc welding (SAW). The mechanical properties of the weld seam have been tested and the metallurgical structures have been analyzed. Conclusions have been obtained as follows: the metallurgical structure of multi-layer butt weld is much more complicated than the monolayer ones; only the last weld layer has the obvious zones of weld zone, heat-affected zone (HAZ) and fusion area; the weld zone and the fusion area will be heat treated with the next layers weld finished; the mechanical property of the multi-layer butt weld is much better than the monolayer weld determined by the corresponding organization.

Seismic Test Methods for Architectural Glazing Systems

1996 ◽  
Vol 12 (1) ◽  
pp. 129-143 ◽  
Author(s):  
Richard A. Behr ◽  
Abdeldjelil Belarbi
Keyword(s):  
Rational Design ◽  
Limit State ◽  
Test Methods ◽  
Test Method ◽  
Ultimate Limit State ◽  
Limit States ◽  
State Data ◽  
Design Procedures ◽  
Seismic Loadings ◽  
Ultimate Limit

An ongoing effort is being made at the University of Missouri-Rolla to develop standard laboratory test methods and codified design procedures for architectural glass under seismic loadings. Recent laboratory work has yielded some promising results regarding the development of an appropriate seismic test method for architectural glass, as well as identifying ultimate limit states that quantify the seismic performance and damage thresholds of various glass types. Specifically, a straightforward “crescendo-like” in-plane dynamic racking test, performed at a constant frequency, has been employed successfully. Two ultimate limit states for architectural glass have been defined: (1) a lower ultimate limit state corresponding to major glass crack pattern formation; and (2) an upper limit state corresponding to significant glass fallout. Early crescendo tests have yielded distinct and repeatable ultimate limit state data for various storefront glass types tested under dynamic racking motions. Crescendo tests will also be used to identify and quantify serviceability limit states for architectural glass and associated glazing components under dynamic loadings. These limit state data will support the development of rational design procedures for architectural glass under seismic loadings.

An Automated Approach for Designing Monopiles Subjected to Lateral Loads

2017 ◽  
Author(s):  
James P. Doherty ◽  
Barry M. Lehane
Keyword(s):  
Limit State ◽  
Ultimate Limit State ◽  
Lateral Loads ◽  
Limit States ◽  
Laterally Loaded Piles ◽  
Improve Design ◽  
Design Procedures ◽  
Automated Algorithm ◽  
Laterally Loaded ◽  
Ultimate Limit

This paper describes an automated algorithm for determining the length and diameter of monopile foundations subject to lateral loads with the aim of minimising the pile weight, whilst satisfying both ultimate and serviceability limit states. The algorithm works by wrapping an optimisation routine around a finite element p - y model for laterally loaded piles. The objective function is expressed as a function representing the pile volume, while the ultimate limit state and serviceability limit states are expressed as optimisation constraints. The approach was found to be accurate and near instantaneous when compared to manual design procedures and may improve design outcomes and reduce design time and costs.

Study on the Microstructure and Mechanical Properties of 15CrMoR

2012 ◽  
Vol 472-475 ◽  
pp. 2731-2735
Author(s):  
Xiao Dong Hu ◽  
Qing Kun He ◽  
Jian Tao Lv ◽  
Yong Zhang
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Weld Zone ◽  
Submerged Arc Welding ◽  
Butt Weld ◽  
Heat Treated ◽  
Electric Arc Welding ◽  
The Relationship ◽  
Submerged Arc ◽  
Better Than

The butt weld sample with the material of 15CrMoR has been manufactured with the bonding methods of manual electric arc welding (SMAW) and submerged-arc welding (SAW). The relationship between the microstructure and the mechanical properties has been analyzed in this paper, and the conclusions have been obtained as followed: only the last weld layer has the obvious zones of weld zone, heat-affected zone (HAZ) and fusion area for the multi-layer butt weld, the weld zone and the fusion area will be heat-treated by the next layer welding; the hardness along central intersection shows a W-shaped distribution, and the zone with normalizing organization has the lowest hardness and the surface layer has the highest hardness; the mechanical properties of the multi-layer butt weld are much better than the monolayer weld’s.

scholarly journals Cross-Slot Antenna with U-Shaped Tuning Stub for Ultra-Wideband Applications

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Dawood Seyed Javan ◽  
Mohammad Ali Salari ◽  
Omid Hashemi Ghoochani
Keyword(s):  
Radiation Pattern ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Design Procedures ◽  
Linearly Polarized ◽  
Dimensional Parameters ◽  
Simulation Results ◽  
Novel Design ◽  
Better Than

A novel design of an ultra-wideband (UWB) slot antenna is presented. This antenna operates as a transmitter and receiver antenna. Effects of the antenna dimensional parameters are studied through experimental and simulation results. Design procedures are developed and verified for different frequency bands. The experimental and simulation results exhibit good impedance bandwidth, radiation pattern, and relatively constant gain over the entire band of frequency. Antenna gain and directivity at boresight and in their maximum states are close to each other and indicate high radiation efficiency. To use the antenna as a linearly polarized antenna, the radiation pattern in E-plane is better thanthat inH-plane.

Status of Declining Rate Filtration Design

1993 ◽  
Vol 27 (10) ◽  
pp. 151-164 ◽  
Author(s):  
John L. Cleasby
Keyword(s):  
Flow Control ◽  
Water Level ◽  
Rational Design ◽  
Theoretical Studies ◽  
Design Procedures ◽  
Design Load ◽  
Water Level Variations ◽  
Full Design ◽  
The Impact ◽  
Experimental And Theoretical Studies

Declining rate filtration is one of several flow control alternatives available for gravity filtration plants with four or more filters. Experimental and theoretical studies of declining rate filtration have provided the foundation for rational design procedures. This paper presents design procedures for estimating the filter system head needed for a declining rate filtration plant, and to predict the water level variations that will occur during operation. The paper also discusses the choice between inlet versus outlet rate limitation, the choice of type of rate limitation device, and the impact of operation of a declining rate filtration plant below full design load.

scholarly journals 21 EFFECTS OF HETEROLOGOUS SEMEN PLASMA AND SEMEN EXTENDERS ON PROGRESSIVE MOTILITY OF FROZEN - THAWED RAM SPERM

2005 ◽  
Vol 17 (2) ◽  
pp. 160
Author(s):  
G. Mataveia ◽  
S.J. Terblanche ◽  
J.O. Nöthling ◽  
D. Gerber
Keyword(s):  
Repeated Measures ◽  
Fixed Effects ◽  
Skim Milk ◽  
Random Order ◽  
Progressive Motility ◽  
Heat Treated ◽  
Ram Sperm ◽  
Bovine Oocytes ◽  
Better Than

Frozen-thawed ram semen crosses the cervix poorly, necessitating laparoscopic insemination. Acceptable fertility can be achieved with frozen-thawed ram semen deposited at the external cervical opening if ram semen plasma (SP) is added (McPhie et al. 2000 14th ICAR 2, 78 abst). Homologous SP improves the fertility of frozen-thawed sperm of boars and dogs. Heterologous SP may have effects as well; the addition of bovine SP increased the ability of buffalo sperm (Syncerus caffer) to fertilize bovine oocytes in vitro (de Haas et al. 2003 Theriogenology 59, 392). The aim of the current study was to compare the effects of SP of rams (SPR), bulls (SPB), and dogs (SPD), protein-free TALP, Triladyl (Minitüb, Tiefenbach, Germany), and skim milk upon longevity and percentage of progressively motile frozen-thawed ram sperm. Three ejaculates from each of six rams (2 Dorpers, 2 Döhne merinos, and 2 merinos), aged 2–4 years, were extended in Triladyl, pooled and frozen as a single batch per ram at 200 × 106/mL in 0.25-mL straws. SPR was obtained from the same rams and SPB from 5 bulls by centrifugation, while the post-sperm fractions were collected from 5 dogs (SPD). Within a species, the SP from different donors was pooled and frozen in aliquots at −18°C. The 108 straws (6 rams, 6 diluents, 3 replicates) were thawed in random order. Once thawed, a straw was emptied into a tube with 0.85 mL of the appropriate fluid at 37°C and kept for 6 h. Percentage of progressively motile sperm was estimated at ×200 magnification immediately and 2, 4 and 6 h after thawing. One person thawed the semen and prepared motility specimens, while another performed all motility evaluations. Data were evaluated by means of repeated-measures ANOVA, with rams as subjects and time and fluid as fixed effects. Non-significant interactions were removed from the model. Means were compared by means of Bonferroni's test (P < 0.05). The model included ram, time, fluid, and ram × fluid, and time × fluid interactions, which were all significant (P < 0.01). Mean motility decreased from each time to the next and were 39.0% (0 h), 26.0% (2 h), 19.6% (4 h) and 12.6% (6 h), SEM 1.38%, n = 108. Mean motility was higher for skim milk (39.9%) than for all other fluids except Triladyl (27.7%), which was better than SPB (13.0%), whereas TALP (20.5%) and SPR (21.9%) were similar to Triladyl and SPB (n = 72, SEM 2.85%). The interactions (ram × fluid or time × fluid) were mainly due to SPD, SPR, Triladyl, and TALP, while milk resulted in the best and SPB in the lowest motility. This study shows that heat-treated skim milk maintains progressive motility of frozen-thawed ram sperm better than the SP of various species and protein-free TALP. In contrast to SPR, skim milk is known to result in poor fertility of frozen-thawed ram semen after cervical insemination. It would thus appear that maintenance of progressive motility in vitro may be a poor indicator of fertility after cervical insemination.

scholarly journals Concrete-Filled Hollow Structural Sections. I: Materials, Cross-Section Classification, and Concentrically Loaded Columns

2021 ◽  
Author(s):  
Kyle Tousignant ◽  
Jeffrey Packer
Keyword(s):  
Reliability Analysis ◽  
Cross Section ◽  
Flexural Members ◽  
Beam Columns ◽  
First Order ◽  
Compression Members ◽  
Hollow Structural Sections

This paper reviews contemporary rules in CSA S16:19, AISC 360-16 and EN 1994-1-1 for concrete-filled hollow structural sections (HSS), covering materials, cross-section classification, and concentrically loaded columns. Results from 453 tests on axially compressed concrete-filled HSS members are compared to predicted strengths using current (CSA S16:19, AISC 360-16 and EN 1994-1-1) and recommended CSA S16 design equations (with limits of validity), and a first-order reliability analysis is performed in accordance with CSA S408-11. The recommendations herein are shown to maintain the current CSA S16:19 Clause 18.2 level of reliability for concrete-filled HSS compression members. Design examples are provided, and results are compared to the counterpart American code (AISC 360-16). This paper is Part I of a two-part series. Part II covers flexural members, beam-columns, tension and shear.

scholarly journals Reliability of Concrete Elements Designed for Alternative Load Combinations Provided in Eurocodes

10.14311/382 ◽  
2003 ◽  
Vol 43 (1) ◽  
Author(s):  
M. Holický ◽  
J. Marková
Keyword(s):  
Structural Design ◽  
Structural Reliability ◽  
Reliability Theory ◽  
Probabilistic Methods ◽  
European Standard ◽  
Limit States ◽  
Design Procedures ◽  
Characteristic Features ◽  
Concrete Elements ◽  
Ultimate Limit

The basic European standard for design of buildings and other engineering works, EN 1990 "Basis of structural design", provides alternative design procedures, for which national choice is allowed. One of the most important questions concerns three fundamental combinations of actions for persistent and transient design situations in the Ultimate limit states. Simple examples of reinforced concrete elements show, that the alternative load combinations may lead to considerably different reliability levels. Probabilistic methods of structural reliability theory are used to identify characteristic features of each combination and to formulate recommendations. However, further calibration studies are urgently needed in order to prepare National annexes to EN 1990 on time.

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