This study assesses physical and chemical properties of fiber reinforced polymer (FRP) composite materials aged in Alaska’s subarctic climate. Carbon FRP (CFRP) and glass FRP (GFRP) samples were collected in 2019 from the exterior and interior of Ted Stevens International Airport (TSIA, retrofitted in 2008) and McKinley Tower (MKT, retrofitted in 2004). Differential scanning calorimetry (DSC) was used to measure glass transition temperature (Tg) and physical aging, FTIR and Raman spectroscopy were used to investigate potential chemical degradation and degree of cure, and scanning electron microscopy (SEM) to evaluate cross-sectional microstructure, respectively. The results indicate that exposure to the subarctic climate had minimal effect on the composites’ and chemical properties. The variability in fiber content at MKT and thermal properties at TSIA suggest there were likely some inconsistencies in the FRP installation that may affect load-carrying capacity. Furthermore, some microcracks were observed in the FRP retrofits which may have resulted from a combination of poor fiber impregnation and thermal cycling.
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Optimizing Truss Structures Using Composite Materials under Natural Frequency Constraints with a New Hybrid Algorithm Based on Cuckoo Search and Stochastic Paint Optimizer (CSSPO)
This article highlights the absence of published paradigms hybridized by The Cuckoo Search (CS) and Stochastic Paint Optimizer (SPO) for optimizing truss structures using composite materials under natural frequency constraints. The article proposes a novel optimization algorithm called CSSPO for optimizing truss structures made of composite materials, known as fiber-reinforced polymer (FRP) composites, to address this gap. Optimization problems of truss structures under frequency constraints are recognized as challenging due to their non-linear and non-convex search spaces that contain numerous local optima. The proposed methodology produces high-quality optimal solutions with less computational effort than the original methods. The aim of this work is to compare the performance of carbon FRP (CFRP), glass FRP (GFRP), and steel using a novel hybrid algorithm to provide valuable insights and inform decision-making processes in material selection and design. Four benchmark structure trusses with natural frequency constraints were utilized to demonstrate the efficiency and robustness of the CSSPO. The numerical analysis findings indicate that the CSSPO outperforms the classical SPO and exhibits comparable or superior performance when compared to the SPO. The study highlights that implementing CFRP and GFRP composites in truss construction leads to a notable reduction in weight compared to using steel.
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- Award ID(s):
- 1916342
- PAR ID:
- 10451909
- Date Published:
- Journal Name:
- Buildings
- Volume:
- 13
- Issue:
- 6
- ISSN:
- 2075-5309
- Page Range / eLocation ID:
- 1551
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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