Citation: Broniewicz, F.; Chy˙ zy, T.; Czech, K.R. Experimental Studies and Numerical Simulations of FRP Poles Failure in the Area of Inspection Hole. Materials 2023, 16, 2238. https://doi.org/10.3390/ ma16062238 Academic Editor: Payam Shafigh Received: 30 January 2023 Revised: 3 March 2023 Accepted: 8 March 2023 Published: 10 March 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Article Experimental Studies and Numerical Simulations of FRP Poles Failure in the Area of Inspection Hole Filip Broniewicz *, Tadeusz Chy˙ zy and Krzysztof Robert Czech Department of Geotechnics and Structural Mechanics, Bialystok University of Technology, 15-351 Bialystok, Poland; t.chyzy@pb.edu.pl (T.C.); k.czech@pb.edu.pl (K.R.C.) * Correspondence: f.broniewicz@doktoranci.pb.edu.pl Abstract: Glass fiber-reinforced polymer (GFRP) utility poles are becoming more widespread in European countries. To ensure the integrity and safety of poles, it is necessary to carefully examine their structural features. The purpose of this paper is to present the numerical model of a column made with the engineering simulation software ANSYS and to compare the experimentally determined values of the stresses that lead to column failure close to the inspection hole with the results obtained using the numerical model. The critical buckling and failure loads for GFRP poles, as well as the associated modes of failure, were correctly predicted by the finite element method used in this study. Failure occurred in the middle of the inspection hole’s longer edge at a stress level of 220–250 MPa. A comparison of the stress using the ANSYS simulation software that led to the destruction of the column with those measured experimentally using strain gauges revealed a good agreement between their values. Keywords: composite structures; GFRP lighting poles; flexural behavior; FEM analysis 1. Introduction Composite poles are becoming more and more significant in the lighting sector. Con- crete and metal poles still account for the vast majority of investments, but they are suscep- tible to the negative impact of environmental conditions. Greater durability and resilience to the weather conditions are qualities of composite materials. Investors have shown a great interest in composite poles for this reason, as well as the possible economic benefits. Because GFRP composite columns are a novel and contemporary structural component, it is not yet entirely established how to determine their load capacity. The anisotropy of the material caused by the method of manufacturing the composite from polymer resin and glass fibers causes difficulties in determining the stresses. The freedom of their mutual arrangement and the different strengths of the components that make up the composite preclude the application of strength standards that are common to isotropic materials. In addition, there remains the problem of evaluating failure models, e.g., by buckling or loss of local stability, which depend on the composition of the composite material, as well as the shape and dimensions of the structure. The search for an alternate material for building lightweight poles and masts was motivated by the desire to get rid of issues such as corrosion and to create a system that required no maintenance. A composite structure might significantly reduce total costs by forgoing the need for galvanizing and corrosion prevention over its lifespan. Investor interest in composite poles has grown significantly due to this, in addition to possible economic advantages. The objective of this study was to employ the finite element method to develop new design guidelines that satisfy both the ultimate limit state and the serviceability limit state requirements, in accordance with European standards relevant to GFRP pole design, EN 40-7 [1] and EN 40-3-x [2–4]. Materials 2023, 16, 2238. https://doi.org/10.3390/ma16062238 https://www.mdpi.com/journal/materials