Author ORCID Identifier
Semester
Fall
Date of Graduation
2024
Document Type
Thesis
Degree Type
MS
College
Statler College of Engineering and Mineral Resources
Department
Civil and Environmental Engineering
Committee Chair
Hota V.S. GangaRao
Committee Co-Chair
Chao Zhang
Committee Member
Rakesh Gupta
Abstract
This study addresses the static response of three Fiber Reinforced Polymer (FRP) structural systems (piles, platforms, and poles) under static loads. This research aims to improve safety and sustainability in modern infrastructure by bridging the knowledge gap currently that exists between the experimental behavior and theoretical predictions.
FRP round piles (18-inch in diameter) were tested under axial compression, shear, four-point bending and fatigue. Both the load-deflection and stress-strain responses were analyzed. Coupon tests were conducted and related to the outcomes of full-scale test data. Two major differences were observed in the response of the bending test specimens with modulus of elasticity in compression being greater than that in tension and failure stress of full-size specimens being nearly half of the coupon specimens. A comprehensive analytical study was carried out by accounting for local effects and principal stress to address these discrepancies. Round piles exhibited conventional performance under compressive and shear loads but demonstrated complex bending response. Local effects had significant impact on the bending response and principal stresses calculated by combining bending, local axial compression, local shear, and global shear bridged the gap between bending stress responses of coupons and those of full-size specimens.
FRP platforms were assessed for lateral load resistance for modular industrial construction. Three sizes of the platforms (3ft x 3ft, 3ft x 6ft, and 3ft x 9ft) were analyzed. Four different bottom connections that included 3/8” angle, ½” angle, 2” x 2” square tube, stiffened bottom with plate were used. Bolt torque levels were varied (0ft-lb, 20ft-lb, and 40ft-lb) to establish joint rigidity and find joint failure under different bolt torques and corresponding load-strain and deflection response are plotted. ETABS (FE) modelling was carried out to compare the experimental data. The joint capacity was also determined following the principles of FRP connection design referring ASCE 74-23. The experimental results revealed that torque level impacts the platform’s stability, with 40 ft-lb torque providing the best performance. Load-deflection responses showed that joint stiffened configurations at the footer level consistently minimized deflection, demonstrating superior stiffness. Notably, platform orientation influenced performance, with platforms loaded along shorter directions exhibiting higher resistance and lower deflection than those loaded along longer directions. Grating also significantly enhanced stiffness through a diaphragm effect.
Finally, cantilever loading response was investigated on carbon fiber cantilever poles. Large deflections were observed on the poles and possible geometrically nonlinear response was investigated. The Euler-Bernoulli nonlinear deflection equation was used and compared with experimental load-deflection response. The experimental data closely matched the theoretical prediction.
In summary, all three FRP configurations highlighted the advantages of FRP's strength, stiffness, and lightweight properties, making them ideal for applications that require weight reduction without sacrificing load-bearing capacity. Furthermore, each configuration emphasized the importance of design considerations—such as connection design, load distribution, and deflection response—that are critical for optimizing FRP performance in a variety of applications. These shared characteristics reinforce FRP's suitability in industries that prioritize safety, sustainability, and structural resilience.
Recommended Citation
Adhikari, Manish, "Static Response of FRP Structural Systems – Piles, Platforms, and Poles" (2024). Graduate Theses, Dissertations, and Problem Reports. 12689.
https://researchrepository.wvu.edu/etd/12689
