Browsing by Author "Vijaya Vengadesh Kumar, J."

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A Regression-Based Approach for Assessing the Buckling Coefficient of Stiffened and Unstiffened Elements
(Institute of Physics, 2023) Raja Lakshmi, J.; Vijaya Vengadesh Kumar, J.
Sustainable construction begins essentially by enabling the application of renewable and recyclable building materials. Cold-formed steel sections providing long-term sustainability and having a high strength-to-weight ratio are finding extensive application in the fields of construction and engineering. The Effective Width Method (EWM) and the Direct Strength Method (DSM) are the primary available analytical methods for the design of these sections. The design procedure for the buckling strength prediction of these analytical methods is inherently dependent on the critical buckling load, which in turn is influenced by the plate buckling coefficients. The plate buckling coefficient of either a stiffened or an unstiffened element is defined for varied boundary conditions and elemental stress ratios. Evaluating the design procedure for the critical buckling load, which is taken as the minimum of the elemental strengths, it was clearly evident that the analytical method yields highly conservative solutions. This conservative prediction is inherently caused by the application of individual plate buckling coefficients that fail to account for the inter-element interaction. The present research strives to propose a regression-based method for the determination of the critical buckling load. The symbolic regression analysis with the aid of machine learning is opted for to obtain more precise and reliable mathematical solutions for the buckling coefficients. The inter-element interaction and varied loading conditions are assessed for their influence and are accounted for in the expressions of the buckling coefficient. More reliable and accurate buckling strength prediction results with a broader conceptual approach are postulated. Â© Published under licence by IOP Publishing Ltd.
Investigation of local buckling behavior of web perforated plain channel stub columns
(Elsevier Ltd, 2024) Francis, R.; Shabhari, A.; Chandrasekar, D.; Vijaya Vengadesh Kumar, J.
As a sustainable material, cold-formed steel (CFS) is increasingly popular in structural components of buildings and industrial storage racks. The plain channel sections having a flange stiffened web element and unstiffened flange elements are prominently used as compression members in CFS systems. These elements are likely to undergo local buckling under compressive loading. The openings or closely spaced perforations along the longitudinal direction of the web for serviceability requirements on buildings and beam level adjustment requirements on storage racks lead to additional complications to the local buckling. Although the Effective Width Method and Direct Strength Method rationally cover the buckling behavior of plain channel sections, the influence of height-to-width ratio with perforations is not effectively accounted for in the design. Limited research details are available in the literature for the web perforations of lipped channels or rack sections. However, these sections do not have unstiffened flanges, where the unstiffened flanges can be more vulnerable to local buckling, e.g., plain channels. The web perforations also make the web more vulnerable to local buckling. This article examines the local buckling behavior of plain channel sections with the influence of web perforations through systematic experimental and comprehensive numerical studies. The influencing parameters of the cross-section geometry are assessed through the principal component analysis (PCA) to understand its correlation with local buckling. The PCA results shed light on mandatory parameters for the elastic critical local buckling load calculation and/or nominal local buckling strength prediction of the plain channel section. © 2024
The Impact of Perforation Orientation on Buckling Behaviour of Storage Rack Uprights
(Springer Science and Business Media Deutschland GmbH, 2023) Sensy, K.; Gupta, A.; Swaminathan, K.; Vijaya Vengadesh Kumar, J.
Industrial storage rack uprights are the most widely used framed structures of thin-walled cold-formed steel members which are meant for the depot of palletized goods. The sensibility of uprights towards local buckling, distortional buckling, global buckling or interaction between these buckling modes in the presence of perforations results in complex behaviour of the uprights. The sustainability of the uprights in terms of the perforations, cross-section geometry, buckling and complexity might be difficult to design through the existing analytical methods alone. The test-based design being expensive leads to the necessity of an analysis-based design approach. The limited analytical methods available in the literature focus on orthogonal perforations and there is no systematic study available in terms of perforation orientation which would imply a minimum net section. This article sheds light effect of increased perforated width due to orientation which directly influences the elastic local critical buckling load calculations. The parametric analysis using finite element software is systematically done for the simple rack section with orthogonal cross-section elements having two idealized transverse web perforations of square and rectangular shape oriented at an angle other than orthogonal angles. The pre-validated FE model is used in this study, and thus the critical elastic buckling loads are procured for various perforation orientations. The CUFSM buckling analysis is done by using the reduced thickness expression recommended in the literature and compared with the FE results. The applicability of reduced thickness equations in accounting perforations in the view of perforation orientation is compared and summarized. Â© 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.