Case Study of Supplemental Steel Structures

2021 ◽  
Author(s):  
Phillip Wiseman ◽  
Raju Subedi

Abstract Supplementary steel provides essential connections between building steel or ground to pipe supports and component supports of power and processing plants. This type of structure is usually with steel members less than 10 feet in length and sustains temperature within the range of the ambient conditions and the pipe or component. Being a connection, the standards and Codes provide an array of stress and geometrical checks that share that of a building and of a pressure boundary. Therefore, the applied engineering mechanics utilized in the analysis of supplemental steel configurations, including but not limited to beams, columns, and frames along with their welded or bolted connections, stretches across multiple engineering disciplines. A study of load cases and load case combinations is performed across multiple configurations of assemblies with industry assumptions incorporated. With the mitigation of sag of pipe systems, study of analytical stress and geometrical checks are evaluated to find any correlations of governing criteria. Additionally, the utilization of two types of structural steel design fundamentals and provisions, Allowable Strength Design (ASD) and Load and Resistance Factor Design (LRFD), are investigated with supplemental steel structures which stem from design considerations of steel buildings. This case study in the analysis of supplemental steel structures provides segue to highlighting how Codes and Standards utilized within the field that overlap other fields.

2018 ◽  
Vol 763 ◽  
pp. 1067-1076 ◽  
Author(s):  
Luigi di Sarno ◽  
Fabrizio Paolacci ◽  
Anastasios G. Sextos

Numerous existing steel framed buildings located in earthquake prone regions world-wide were designed without seismic provisions. Slender beam-columns, as well as non-ductile beam-to-column connections have been employed for multi-storey moment-resisting frames (MRFs) built before the 80’s. Thus, widespread damage due to brittle failure has been commonly observed in the past earthquakes for steel MRFs. A recent post-earthquake survey carried out in the aftermath of the 2016-2017 Central Italy seismic swarm has pointed out that steel structures may survive the shaking caused by several main-shocks and strong aftershocks without collapsing. Inevitably, significant lateral deformations are experienced, and, in turn, non-structural components are severely damaged thus inhibiting the use of the steel building structures. The present papers illustrates the outcomes of a recent preliminary numerical study carried out for the case of a steel MRF building located in Amatrice, Central Italy, which experienced a series of ground motion excitations suffering significant damage to the masonry infills without collapsing. A refined numerical model of the sample structure has been developed on the basis of the data collected on site. Given the lack of design drawings, the structure has been re-designed in compliance with the Italian regulations imposed at the time of construction employing the allowable stress method. The earthquake performance of the case study MRF has been then investigated through advanced nonlinear dynamic analyses and its structural performance has been evaluated according to Eurocode 8-Part 3 for existing buildings. The reliability of the codified approaches has been evaluated and possible improvements emphasized.


2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
S. Pinarbasi ◽  
T. Genc ◽  
E. Akpinar ◽  
F. Okay

Thirty-six years after its publication, Turkish Building Code for Steel Structures was replaced with a more rational specification, Specification of Design and Construction of Steel Structures (SDCSS), which was prepared almost entirely based on the current American steel design specification (AISC 360-16). European steel design specification (EC3) is also widely used in Turkey for the design of steel structures constructed with the collaboration of Turkish and European companies. It is essential for a steel designer using both SDCSS and EC3 to comprehend the basic differences between these specifications. This study aims to compare the design guidelines defined in AISC 360-16 (so in SDCSS) and EC3 for rolled I-shaped steel members subjected to axial compression thoroughly. For various steel grades, member lengths, and 153 different European I/H sections, design buckling resistances and design compressive strengths are computed and compared. It is shown that there are at most 3% difference between the effective areas computed using both specifications. It is highly recommended that the change of cross section class be allowed while calculating design buckling resistances. For the studied sections and steel grades, the resistance-to-strength ratios are found to be as high as 1.24 but not smaller than 0.907.


2007 ◽  
Vol 60 (2) ◽  
pp. 241-250
Author(s):  
Roberto T. Leon

In late 2005, the American Institute of Steel Construction issued its most recent Specification for Structural Steel Buildings (ANSI/AISC 360-05). This specification includes updated design provisions in both allowable strength design (ASD) and load and resistance factor design methods (LRFD), and incorporates the design provisions for hollow structural sections and single angles. Amongst the major changes are a complete revamping of the methodologies for assessing stability of framed structures, new provisions for composite columns and updated material requirements. This paper will describe the changes and highlight those of practical significance.


2021 ◽  
Author(s):  
Kshitij P. Gawande ◽  
Alex Mayes ◽  
Raju Subedi

Abstract Endplates are widely used in the industry to attach supplementary steel structures to main building frames. These endplates can be attached to the building steel using a bolted connection or a welded connection. Industry often favors bolted connections due to ease of installation and availability of qualification methods per AISC 360 Design Guides. However, there are some applications where a welded connection is preferable, such as, cases requiring reduction of number of parts supplied or applications with higher chance of vibration causing loosening of bolts. The present case study discusses evaluation of stresses in welded endplates due to forces and moments from the attaching supplementary steel members. The study considers various welded connection scenarios including an endplate welded on two opposite sides and an endplate welded on all four sides. The stress distribution in the plate is studied using finite element analysis with wide flange and tube steel members attaching to it. ANSYS mechanical is used to perform the finite element analysis. Multiple combinations of plate sizes, weld patterns, and attaching member sizes are analyzed to provide a well-rounded solution. An analytical model is developed for the stress evaluation as well and the results are compared with the finite element model. The study is intended to provide an efficient methodology for plate evaluation and qualification.


Author(s):  
Daigo Watanabe ◽  
Kiminobu Hojo

This paper introduces an example of structural integrity evaluation for Light Water Reactor (LWR) against excessive loads on the Design Extension Condition (DEC). In order to assess the design acceptance level of DEC, three acceptance criteria which are the stress basis limit of the current design code, the strain basis limit of the current design code and the strain basis limit by using Load and Resistance Factor Design (LRFD) method were applied. As a result the allowable stress was increased by changing the acceptance criteria from the stress basis limit to the strain basis limit. It is shown that the practical margin of the LWR’s components still keeps even on DEC by introducing an appropriate criterion for integrity assessment and safety factors.


1978 ◽  
Vol 104 (9) ◽  
pp. 1427-1441
Author(s):  
John W. Fisher ◽  
Theodore V. Galambos ◽  
Geoffrey L. Kulak ◽  
Mayasandra K. Ravindra

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