Effect of Supporting Base System on the Flexural Behavior and Toughness of the Lighting GFRP Poles

Abstract

Due to the high risk of common traffic electric poles, the use of glass fiber reinforced polymer (GFRP) material in electric poles has become essential due to its excellent advantages such as high strength to weight ratio, corrosion resistance, and electrical insulation, which keeps people safe. To reduce the accidental effect of street lighting poles on humans, the generated energy during the collision must be absorbed. Experimental and numerical investigations were carried out to identify the efficiency of tapered GFRP electric poles with handle doors using steel sleeve bases until the occurrence of failure. Six full-scale cantilever bending tests were performed to investigate the strength and ductility of the GFRP pole. Moreover, finite element (FE) models were developed using Abaqus software and verified against tests to provide alternative tools instead of lab experiments. An extensive parametric study was carried out to predict the effect of the GFRP pole wall thickness, base plate geometric (length, diameter, and wall thickness), electric cable hole diameter, material properties, and base sleeve geometric (length and wall thickness) on the toughness of the GFRP pole. Based on the results of the load–displacement (P–Δ) curves, the flexibility of the GFRP poles was directly proportional to their length and the local buckling failure often occurred at the handle door. Strengthening the zone of the handle door using a steel ring was investigated to prevent the local buckling failure at this part. However, the wall thickness of the GFRP pole, base sleeve height, base plate dimensions, and base plate material properties were the most effective parameters to enhance accidental energy absorption through large deformation kinematics. The base sleeve thickness had a slight direct effect on the ductility and toughness of the GFRP pole.

Measuring and Rigidity Moduli of GFRP Experimentally

“…Nawar in 2022 indicated that strengthening the handle door with a steel ring increased the ultimate capacity of the GFRP pole and prevented the fracture of this region. Moreover, the base system became the most effective for pole deformation [17]. Feng in 2021 showed that the straight hollow-section concrete-filled GFRP tube columns generally behaved in a comparable manner before the GFRP tube failure.…”

Experimental Studies and Numerical Simulations of FRP Poles Failure in the Area of Inspection Hole

“…In [ 25 ], the authors examined the impact of the base plate dimensions and the location of the inspection hole on the load capacity of GFRP columns. In the first stage, tests were carried out for four sizes of the base plate (widths from 250 to 500 mm) and three different plate thicknesses (10 mm, 15 mm and 20 mm).…”

Behavior of Centrifuged GFRP Poles Under Lateral Deflection

“…Altanopoulos et al (2021) concluded that it is possible to use the FEM with confidence in the analysis and design of GFRP structures, such as utility line poles and wind turbine towers, without the high cost associated with experimentation [14]. Nawar et al (2022) figured that the flexibility of the GFRP poles was directly proportional to their length, and the local buckling failure often occurred at the handle door [15]. In 2019, Several non-linear finite element models were developed to determine the appropriate cable diameters and their associated spacing levels that increased the tower stiffness and decreased the maximum tensile and compressive stresses, which would meet both the manufacturing constraints and strength requirements [16].…”