An Experimental and Numerical Investigation on Performance of Steel Beams with Circular Web Openings

Abstract

In the present study, experimental and numerical investigation is carried out to study the effect of diameter of circular openings on the performance of steel beams. Steel I section ISMB150 @ 14.9 kg/m, of 900 mm overall span and 800 mm effective span is chosen for the experimental and numerical investigation with a simple support condition at both the ends. Performance of ISMB 150 section without and with circular web openings of diameter 50 mm, 75 mm and 100 mm is studied in the present investigation. Experimental analysis is performed by subjecting the steel sections to mid-point loading in Universal Testing Machine (UTM). Whereas numerical analysis is performed for the steel sections using ANSYS FEM software. ANSYS FEM software predicts the similar variation of load-deflection curves for as that of experimental results for all the steel beams. From both experimental and numerical investigation, solid beam without web opening takes more load and deflects less as compared to steel beams with circular web openings. Further, as diameter of circular opening increases, load carrying capacity decreases and deflection at mid-span increases.

Introduction

Steel structures are widely used in modern construction due to their high strength, durability, and versatility, making them suitable for high-rise buildings, bridges, industrial facilities, and large-span roofs. Prefabrication allows faster assembly, while steel’s ductility improves performance under seismic and wind loads. However, traditional solid-web steel beams can create challenges for service installations like HVAC ducts and pipelines. To address this, beams with web openings are increasingly used, though careful design is required since openings affect stress distribution and failure behavior. INSDAG guidelines recommend placing openings at the web center, away from supports, ideally within the middle third of the span, with proper spacing and size limits.

The study uses ANSYS FEA software to analyze steel beam behavior under various conditions, reducing reliance on physical testing. Experimentally, ISMB150 steel beams—both solid and with circular web openings of varying sizes and spacing—were tested under three-point loading on a Universal Testing Machine, with deflection measured via LVDT. Corresponding 3D numerical models were created in ANSYS to simulate beam behavior, enabling comparison of solid versus perforated beams in terms of structural performance.

Conclusion

In the present study, experimental and numerical investigation is carried out to study the effect of diameter of circular openings on the performance of steel beams. Steel I section ISMB150 @ 14.9 kg/m, of 900 mm overall span and 800 mm effective span is chosen for the experimental and numerical investigation with a simple support condition at both the ends. Performance of ISMB 150 section without and with circular web openings of diameter 50 mm, 75 mm and 100 mm is studied in the present investigation. Experimental analysis is performed by subjecting the steel sections to mid-point loading in UTM and numerical analysis is performed for the steel sections using ANSYS FEM software The important conclusions drawn from the present study are as follows. 1) All the steel beams show similar variation in load-deflection curve when tested experimentally in UTM and when analyzed numerically in ANSYS FEM software. 2) ANSYS FEM software predicts the similar variation of load-deflection curves for as that of experimental results for all the steel beams. Also, FEM results match fairly well with the experimental results. 3) From both experimental and numerical investigation, solid beam without web opening takes more load and deflects less as compared to steel beams with circular web openings. Further, as diameter of circular opening increases, load carrying capacity decreases and deflection at mid-span increases.

References

[1] Resmi M and Preetha P (2016), “Finite Element Analysis to Compare the Deflection of Steel Beam with and without Web Openings”, International Organization of Scientific Research Journal of Civil Engineering. [2] Mork hade G and Gupta M (2015), “An Experimental and Parametric Study on Steel Beams with Web Openings”, International Journal of Advanced Structural Engineering. [3] Morkhade G and Gupta M (2021), “Experimental and Analytical Investigation of Castellated Beams with Varying Openings Eccentricity”, Journal of the institution of engineers, Vol. 102. [4] SP 6 (Part 1):1964, “Code of Practice for Structural Steel Sections”, Bureau of Indian Standards, New Delhi, India. [5] IS 800 :2007, “General Construction in Steel Code of Practice”, Bureau of Indian Standards, New Delhi, India. [6] Institute for Steel Development and Growth (INSDAG) Manual.

Copyright

Copyright © 2025 Chandana R, Chidananda G. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.