Open Access

ARTICLE

Structural Integrity of GFRP Absorption Towers under Lifting Loads: Design and FEA Validation of a Bolt-On Steel Reinforcement System

Matías Mariqueo^1,2, Rodrigo Valle³, César Garrido⁴, Sebastián Andrés Toro⁵, Víctor Tuninetti^1,*

1 Department of Mechanical Engineering, Universidad de La Frontera, Temuco, Chile
2 Mechanical Engineering Program, Universidad de La Frontera, Temuco, Chile
3 Construction Multidisciplinary Research Group, Facultad de Arquitectura, Construcción y Medio Ambiente, Universidad Autónoma de Chile, Talca, Chile
4 Department of Mechanical Engineering, Universidad del Bío-Bío, Concepción, Chile
5 Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, USACH, Av. Bernardo O’Higgins 3363, Santiago, Chile

* Corresponding Author: Víctor Tuninetti. Email:

Computer Modeling in Engineering & Sciences 2026, 148(2), 13 https://doi.org/10.32604/cmes.2026.078932

Received 10 January 2026; Accepted 23 February 2026; Issue published 28 August 2026

Abstract

Lifting and maintenance of existing Glass-Fiber Reinforced Polymer (GFRP) absorption towers pose significant structural risks, as these units were often not designed for such loads. Previous research has established that lifting these sections without reinforcement results in critically low factors of safety (1.9–2.5) due to high stress concentrations on the composite flanges. This paper presents the design, analysis, and validation of a novel bolt-on steel lifting system to mitigate these structural risks. A system comprising a 32 mm thick ASME A36 steel blind flange with integrated lifting lugs and half-moon stiffeners was designed to mount to the tower’s existing bolt pattern. Using Finite Element Analysis (FEA) with the Hashin failure criterion, the full assembly of steel elements and GFRP tower section was simulated under vertical, horizontal, and complex transition-al-angle lifting scenarios. The new lifting system substantially improves structural integrity. The design effectively transfers stresses from the fragile GFRP flange to the robust steel elements, resulting in a 31% reduction in maximum stresses on the GFRP shell during vertical lifts and a 35% reduction during horizontal lifts. Consequently, the minimum safety factor for the GFRP tower increased from 1.9 to 3.8 in the horizontal case and from 4.1 to 11.7 in the vertical case, representing an average safety factor increase of 286%. The steel components themselves were validated with safety factors exceeding 5, compliant with lifting standards. This paper provides a validated engineering blueprint for a bolt-on system that ensures the safe and reliable lifting of GFRP composite towers. This design successfully resolves the critical safety flaws identified in our previous analysis.

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