Developments in the design of welded HSS truss joints with RHS chords

1983 ◽  
Vol 10 (1) ◽  
pp. 92-103 ◽  
Author(s):  
Jeffrey A. Packer

Recent developments in design proposals for rectangular hollow section truss joints are reviewed for statically loaded, single chord, planar truss connections having one compression bracing member and one tension bracing member welded to the chord face, with either a small gap or an overlap at the connection. After comparison with the results of many joint tests, undertaken both in isolation and in complete trusses in other countries, a relatively simple procedure for the design of such joints is advocated. The design method is presented in a format compatible with the Canadian Standards Association Limit States Design Code for Steel Structures.

Author(s):  
Mohamed S. Abu-Yosef ◽  
Ezzeldin Y. Sayed-Ahmed ◽  
Emam A. Soliman

Steel connections transferring axial and shear forces in addition to bending moment and/or torsional moment are widely used in steel structures. Thus, design of such eccentric connections has become the focal point of any researches. Nonetheless, behavior of eccentric connections subjected to shear forces and torsion in the ultimate limit state is still ambiguous. Most design codes of practice still conservatively use the common elastic analysis for design of the said connections even in the ultimate limit states. Yet, there are some exceptions such as the design method proposed by CAN/CSA-S16-14 which gives tabulated design aid for the ultimate limit state design of these connections based on an empirical equation that is derived for ¾ inch diameter A325 bearing type bolts and A36 steel plates. It was argued that results can also be used with a margin of error for other grade bolts of different sizes and steel of other grades. As such, in this paper, the performance of bolted connection subject to shear and torsion is experimentally investigated. The behavior, failure modes and factors affecting both are scrutinized. Twelve connections subject to shear and torsion with different bolts configurations and diameters are experimentally tested to failure. The accuracy of the currently available design equations proposed is compared to the outcomes of these tests.


1986 ◽  
Vol 13 (4) ◽  
pp. 460-473 ◽  
Author(s):  
Jeffrey A. Packer

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.


Author(s):  
Zhenyong Zhang ◽  
Yawei Zhou ◽  
Jinyuan Zhang

Although the traditional method based on stress analysis is simple and convenient, the main limitation is that it does not reflect the actual failure mechanisms (or limit states). A pipeline network database of about 40 thousand kilometers comprising 258 design cases that represent combinations of steel grade, diameter, pressure, and location class is established, in order to evaluate and improve the design factors specified in the Chinese standard “Code for design of gas transmission pipeline engineering” (GB 50251). Referring to the research report “Target Reliability Levels for the Design and Assessment of Onshore Natural Gas Pipelines” accomplished by C-FER in 2005, the critical wall thicknesses and corresponding equivalent design factors are calculated by using reliability-based method to meet specified reliability targets. The research shows that the equivalent design factors obtained by Reliability-Based Design (RBD) method tend to increase as the pipe diameters get larger. The new design factors are smaller than those specified in the design code for pipelines with small diameter in location class 1 and 2, and larger than those in the design code for the other pipelines. Therefore, design factors are modified in each location class. The new factors are specific to pipes with small diameter (D ≤ 508mm), medium diameter (508mm < D < 711mm), and large diameter (711mm ≤ D ≤ 1219mm), thus enhancing the rationality and practicability of design factors.


1974 ◽  
Vol 1 (1) ◽  
pp. 1-13 ◽  
Author(s):  
D. J. Laurie Kennedy

The greater rationality of limit states design as compared to working stress design is developed to show that limit states design leads to a more consistent probability of failure and that neither overly safe and therefore uneconomic structures nor structures with insufficient safety should result from this design methodology.This rationality is extended in the limit states design method in that the performance of the structure and its components is checked against the various limit states at the appropriate load levels. Thus the limit states of serviceability are checked at specified load levels and of strength and stability at the factored load levels.Functions are presented for the two sides of the inequality:[Formula: see text]A comparative design of a 20-storey structure selected to provide a wide range of variables shows that limit states design as proposed results in a structure comparable to that designed by working stress method with a moderate saving in the weight of steel. Some simple design examples are worked out to show the basic similarities between working stress design and limit states design and that the two methods are of about equal complexity or simplicity. It is believed, because the designer will have to check the ultimate resistance against the effect of the factored loads, that he will develop a greater awareness of the behavior of the material and members with which he is working.


1984 ◽  
Vol 11 (4) ◽  
pp. 824-832
Author(s):  
R. A. Dorton

The Ontario Highway Bridge Design Code was first issued in 1979 and has since been used for the design and evaluation of most bridges in Ontario. The code is in metric SI units, written in a limit states format, and calibrated to a target safety index value of 3.5. It has produced bridges with a more consistent safety level and capable of carrying design live loads twice those previously prescribed. Feedback from users was obtained and their concerns considered in formulating the provisions of the seeond edition in 1983. New bridge codes can be written in a short time and implemented most readily within a relatively small jurisdiction having control of all highways, bridges, and vehicles. Communications between the writers and potential users are important throughout the preparation and implementation phases. It is essential that a commentary volume be issued with a code to ensure correct understanding and interpretation of new provisions. Computer programs should be available, incorporating the code technology before the use of a new code becomes mandatory. Future code needs and likely areas of new development are outlined in the paper. Key words: calibration, codes, computer systems, highway bridges, loadings, safety, structures.


2021 ◽  
Vol 10 (12) ◽  
pp. 174-179
Author(s):  
Özlem Çavdar

In earthquake engineering, a performance-based design method is used to determine the level of the expected performance of the structures under the earthquake effect. The level of performance is related to the damage situation that could be occurred in the structure after the earthquake. In the performance-based structural design, it is predicted that more than one damage levels emerge under one certain earthquake effect. In this study, the seismic behavior of steel structures with plan irregularities in the Turkey Building Earthquake Code in the 2018 (TBEC-2018) is investigated by the nonlinear static analysis methods. The selected steel structures are located in İzmir, Turkey. The Turkey Earthquake Code in 2018 is considered for assessing seismic performance evaluation of the selected moment-resisting frame steel building. Four different A3 type irregularity was investigated. The steel building with no irregularity in its plan. was selected as the structure of the reference. The performance goals of the five different steel structures are evaluated by applying the pushover and procedures of the TBEC-2018. The steel structures were compared by obtaining pushover curves for both the X and Y directions. The results show that the effects of A3 type irregularity should be not considered in design and buildings without irregularities are safer.


2013 ◽  
Vol 12 (2) ◽  
pp. 213-220
Author(s):  
Marian Giżejowski ◽  
Zbigniew Stachura

Issues related to safety requirements for steel elements subjected to different stress resultants in reference to limit states design philosophy according to Structural Eurocodes PN-EN and national codes PN-B are dealt with in the paper. The calibration of partial cross-section resistance factors is discussed on the basis of elements of steel floor structures where the permanent load component and the live load component of variable actions are the only components of load combinations. Final conclusions for their practical application in the codification process are formulated and values of partial factors for cross section resistance are proposed.


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