Composite Poles Research Articles

Study of different connection types in modular composite energy poles and comparison with monolithic reinforced concrete energy poles

Study of different connection types in modular composite energy poles and comparison with monolithic reinforced concrete energy poles

Predicting the Climatic Resistance of the Material and the Durability of the Structural Elements of the Composite Tower of the Power Line

Comparative analysis of two models for predicting residual resource of polymer composite, one proposed by specialists from RS Technologies Inc and the other proposed by Institute of Oil and Gas Problems SB RAS (Russia), was carried out to obtain service life of composite poles for power transmission lines manufactured by RS Technologies Inc (Canada) for cold climate of Republic of Sakha (Yakutia). Models are based on experimental studies of strength of materials during accelerated and full-scale climatic tests. The difference lies in the presence of parameters of climatic zone and test methods in the first model, while the second model considers changes in physical and mechanical properties and structure of materials during aging under conditions of full-scale exposure and accelerated climatic tests. Comparison of results of predicting the durability of fiberglass products in cold climate of Yakutsk (Russia) according to Institute of Oil and Gas Problems SB RAS model and similar products in Calgary (Canada) climate (the closest in terms of climate conditions) according to RS Technologies Inc model showed the same results. Service life of composite support material was approximately 120 years with specified level of permissible decrease in characteristic property index of 75% of the original.

Full Scale Evaluation of GFRP Confined Softwood after Long-Term Exposure to High Humidity Environment

Plantation softwood timber poles are associated with low natural durability, and it is also not clear what the effects of the high humidity environment on the long-term performance of composite action integrity of such a system. This paper presents a durability study for the proposed composite poles using (GFRP) glass fiber-reinforced polymer as a confinement system on wooden poles sourced from plantation softwood timber. Radiata pine poles of 6 m length were wrapped with multiple layers of 0°/90° woven roving biaxial E-glass fiber sheets through a wet layup process as confinement. The prepared GFRP softwood poles were then subjected to high humidity environmental conditions of up to 95 ± 2% relative humidity and 22 ± 2 °C temperature for a period of 30 months. Various lengths of confinement were considered in this study ranging from 0% to 70% of the span length. The poles had a span length of 5.4 m and were tested using a three-point bending test. Results showed that the proposed confinement system of GFRP-softwood provided a satisfactory long-term performance and the high humidity environment did not greatly affect the improvement in the mechanical performance that the GFRP system provided.

Reliability Assessment of Transmission Poles

The structural reliability of round wood and fiber-reinforced polymer (FRP) composite transmission poles is investigated. Numerical reliabilities at ultimate loads for 20 poles are computed and compared. The main inference from this limited study is that FRP poles showed higher structural reliability than wood poles; the average reliability index of FRP poles is more than three times that of wood. It is suggested that composite poles offer better long-term performance, resilience and reliability when used in hurricane-prone and other highload areas.

Emergence of mass in the gauge sector of QCD* *Supported by the grant PID2020-113334GB-I00/AEI/10.13039/501100011033 of the Spanish AEI-MICINN, and the grant Prometeo/2019/087 of the Generalitat Valenciana

It is currently widely accepted that gluons, while massless at the level of the fundamental QCD Lagrangian, acquire an effective mass through the non-Abelian implementation of the classic Schwinger mechanism. The key dynamical ingredient that triggers the onset of this mechanism is the formation of composite massless poles inside the fundamental vertices of the theory. These poles enter the evolution equation of the gluon propagator and nontrivially affect the way the Slavnov-Taylor identities of the vertices are resolved, inducing a smoking-gun displacement in the corresponding Ward identities. In this article, we present a comprehensive review of the pivotal concepts associated with this dynamical scenario, emphasizing the synergy between functional methods and lattice simulations and highlighting recent advances that corroborate the action of the Schwinger mechanism in QCD.

Parametric Studies on Finishing of AZ31B Magnesium Alloy with Al2O3 Magnetic Abrasives Prepared by Combining Plasma Molten Metal Powder with Sprayed Abrasive Powder

High-performance iron-based Al2O3 magnetic abrasive powder (MAP) prepared by combining plasma molten metal powder with sprayed abrasive powder is used for magnetic abrasive finishing (MAF) of AZ31B magnesium alloy to remove surface defects such as creases, cracks, scratches, and pits generated during the manufacturing process of the workpiece, and to reduce surface roughness and improve its wear and corrosion resistance. In order to solve the problem of magnetic abrasive powder splash in the MAF process, the force analysis of the MAP in the processing area is conducted, and a composite magnetic pole processing device was designed and simulated to compare the effects of both devices on MAF, confirming the feasibility of composite magnetic pole grinding. Then, experiments have been designed using Response Surface Methodology (RSM) to investigate the effect of four factors-magnetic pole rotation speed, grinding gap, magnetic pole feed rate, magnetic abrasive filling quantity-on surface roughness and the interactions between them. The minimum surface roughness value that can be obtained is used as the index for parameter optimization, and the optimized parameters are used for experiments, and the results show that the established surface roughness model has good predictive ability.

Composite electricity distribution poles for Kenya: a predictive, systematic and meta- analytic review

Increasing levels of global forest denudation have led to increased global warming due to rising levels of greenhouse gases in the atmosphere. This is further exacerbated by the need for poles for power distribution among other uses. A need, therefore, exists to venture into alternative poles that are environmentally friendly and address the effects of deforestation. The paper addresses this emerging issue by suggesting the adoption of composite poles for power distribution in Kenya. Composite poles are those whose outer materials are ultraviolet stabilized, recyclable, and resistant to corrosion and attacks such as from insects and rodents. The outer material also has minimum water porosity. The inner material, on the other hand, is made of both fiber and Polyurethane material. The fibres are organic and can be of industrial or biological materials such as fiberglass, carbon fibre, or plant fibre, among others. This paper analyses the composition, available technologies, socio-economic benefits as well as risks to be mitigated by the adoption of composite poles in Kenya. Analysis of the total cost per pole installed for various pole types was done. Data collection methods involved interviewing Kenya Power and Lighting Company (KPLC) staff, the observation made at the Limuru factory, and the use of existing documentation by KPLC and the Kenya Bureau of Standards (KEBS). The paper reviewed studies done by KPLC and standards developed thereof by KEBS. Further key attributes of various pole technologies were compared and a comparison of composite poles with wood and concrete poles was carried out. In addition, the technical features of poles were compared. Data collected was analysed and the results were presented in tabular forms. The cost analyses of the various poles and a summary of the failure of wooden poles in various regions throughout Kenya were also covered. The study has demonstrated based on a life-term analysis, that composite poles would save up to 40% of the total costs incurred for projects that are replacing wooden and concrete poles over 80 years. This translates to about KES 51, 868, 363 per composite lifetime or about KES 648, 354 per year (USD 5,533.60 /a) in addition to the added benefits of easier and quicker installations, low operation costs, and longevity. Further still, Composites poles would significantly impact the amount of money charged to connect new clients to the Grid electricity. The study concludes by indicating that a need exists for further analysis of the cost elements using Net Present Value (NPV) approaches.

Study of Full Composite Pole-Aluminum Conductor Composite Core System Ice-Shedding Response

Full composite pole-aluminum conductor composite core system is gradually used in the 10kV distribution network. In order to study the different ice-shedding forms of the dynamic response of this distribution system, the author established a conductor-insulator and pole-conductor system with two finite element models to study the linear section and corner section of the line in different forms of ice-shedding and ice-shedding rate under the influence of the line ice-shedding response degree. The results show that the pole-conductor model is a good model for the design of distribution lines with carbon fiber cores. The results also show that the ice jump height of the pole-conductor model is smaller than that of the conductor-insulator model, which is related to the coupling relationship between the composite pole and aluminum conductor composite core. The stay wire of the corner pole will absorb most of the energy generated by ice-shedding. In addition, when non-uniform ice-shedding, the line vibration is more violent, the jump height is higher, and the maximum axial force generated after ice-shedding is greater, which has certain safety risks.

Barriers to Sustainable Composite Poles Adoption in Infrastructure

Fibre-reinforced polymer (FRP) poles are, next to wooden poles, a more environmentally friendly solution than traditional steel or concrete poles. In addition to having a lower negative impact on the environment, they are characterised by durability, resiliency, and corrosion resistance. But, unfortunately, the range of their use, both in Poland and around the world, is limited. In this paper, the authors try to identify the most important barriers to the wide use of FRP poles in infrastructure construction. They also propose some actions to change this unfavourable situation from the sustainable development point of view

Research and Application of Light Combined Composite Material Holding Pole

Suspension spanning frame is widely used in the construction of newly constructed overhead transmission lines, and plays an important role in protecting the safety of the objects being crossed. The temporary beam of the suspension cable-type span is installed on the transmission tower, and the impact load in the event of an accident will be transmitted to the transmission tower through the temporary beam.Therefore,the installation of temporary beams will have an important impact on the safety of transmission towers. This paper analyzes the typical installation method of the suspension cable spanning frame on the transmission tower, discusses the dynamic simulation method of the suspension cable spanning frame and the transmission tower under the impact of the conductor, selects a 500kV transmission line crossing project to carry out the wire breakage Analysis of the impact of the lower impact load on the transmission tower. The results show that the wrong installation method will have a significant adverse effect on the safety of the transmission tower. Based on the analysis results, suggestions for the installation of temporary beams were proposed, which provided a reference for the suspension construction of the suspension bridge.

Safe and Sustainable Design of Composite Smart Poles for Wireless Technologies

The multiplicity of targets of the 5G and further future technologies, set by the modern societies and industry, lacks the establishment of design methods for the highly multidisciplinary application of wireless platforms for small cells. Constraints are set by the overall energy concept, structural safety and sustainability. Various Smart poles and Light poles exist but it is challenging to define the design drivers especially for a composite load-carrying structure. In this study, the design drivers of a composite 5G smart pole are determined and the connecting design between finite element modelling (FEM), signal penetration and computational fluid dynamics (CFD) for thermal analysis are reported as an interdisciplinary process. The results emphasize the significant effects of thermal loading on the material selection. The physical architecture, including various cutouts, is manipulated by the needs of the mmW radios, structural safety and the societal preferences of sustainable city planning, i.e., heat management and aesthetic reasons. Finally, the paint thickness and paint type must be optimized due to radome-integrated radios. In the future, sustainability regulations and realized business models will define the cost-structure and the response by customers.

Research on Construction Method, Risk Identification and Evaluation Technology of UHV AC Composite Cross Arm Pole and Tower

The research on construction method of UHV AC composite cross arm pole and tower mainly combines the material and structural characteristics of composite cross arm insulator, analyzes the danger sources which may cause damage to construction links such as packaging, transportation, storage, construction hauling, lifting and installation, and then this paper conducts evaluation, and proposes corresponding construction measures, thus forming the construction technical scheme of UHV AC composite cross arm pole and tower. This paper conducts analysis and assessment to the risk (danger source) of damage to composite cross arm insulator during the construction by utilizing the risk evaluation method, and then proposes corresponding construction full-protection measures and counter measures targeting the assessment results.

Research on the Multi-factor Aging Resistance for the materials of Composite Poles

A multi-factor faster aging test with 5000h was carried to evaluate the aging resistance of running composite tower materials outdoor, which accelerates aging test includes different factors such as solar aging, mechanical aging, electrical aging, heat aging and environmental aging of materials. The flexural modulus retention rates of resin-based and resin-system composite samples decrease with aging time, except for the sample made of isophthalic unsaturated polyester, the flexural modulus retention rates of other composite samples are above 90%. Meanwhile, the modulus of the unsaturated polyester resin and E44 epoxy resin decreased significantly, the modulus retention of unsaturated polyester rate was 88% after aging test, and the damage flextural strength for E44 epoxy based glass fiber composite sample was 92%, while the bending strengh retention ratioes of other composite materials were higher than 96%. The multi-factor accelerated aging test results show that the modified polyurethane resin and vinyl resin have good aging resistance, and meet the application for composite materials’ poles and crossarms outdoor.

An Improved Polyurethane using as Glass Fiber Reinforced Polymer Transmission Poles and Crossarms

By the design of molecular structure, improved polyurethane was synthesized and the material exhibited excellent mechanic properties, electrical insulation, resistance to chemical corrosion and UV aging. Its tensile and flexural strength were 58.4 MPa and 101.2 MPa; surface and volume resistivity were 9.68 × 1015 Ω and 2.60 × 1016 Ω.cm, respectively; and their loss modulus was less than 13% exposed under serious chemical substance and UV irradiation. Moreover, the properties of the polyurethane were superior to traditional epoxy and unsaturated polyester resin. Herin, resulted composite material poles and cross arms were operation under demonstration line, and accumulated relevant operating parameters.

Static and dynamic analysis of wood laminated composite poles using FEA

Wood laminated composite poles having polygonal cross section are considered as latest products. The synthetic resins are used as binders for these poles. These poles possess various advantages in comparison to wooden poles of solid type. Hence, they are replacing solid wood poles in transmission and distribution services. The present work was carried out to analyse the effect of number of strips and strip thickness on the deflection and stress. Three levels of strip thickness and three levels of number of strips are taken as variables. In this current work an attempt has been made to present the Static and Dynamic analysis of uniform cross-section and tapered cross-section composite pole and the results show that Tapered cross-sectional pole is having lesser frequency at higher modes, lesser amplitude of vibration which is an advantage in selecting the desired cross-section of the pole. It was observed through this project study that tapered pole consisting of 9 strips and 15 mm thickness is best suited for supporting the power transmission lines.

Разработка и испытание комбинированных стеклопластиковых опор ЛЭП в суровых климатических условиях

Разработка и испытание комбинированных стеклопластиковых опор ЛЭП в суровых климатических условиях

Structural Assessment of Fiber-reinforced Polymer Composite Electric Poles

Engineers are increasingly tasked with designing and operating structures that incorporate the philosophy of resiliency across a variety of critical infrastructure sectors. Electric distribution and transmission systems are examples of the critical infrastructure sectors. The majority of existing electrical poles supporting electric distribution systems in the United States are made out of wood. It is estimated that up to 3.6 million existing electric wood poles have to be replaced every year. One of the primary hardening strategies is upgrading wooden electric poles and supporting structures with stronger materials that withstand hurricane-force winds. This paper presents finite element analysis of fiber-reinforced polymer composite poles including parametric studies on geometric characteristics, fiber orientation, number of layers, and lamina thickness.

Mechanical Properties of Finger-Jointed Wood from Composite Utility Poles Made of Small Diameter Timber

Mechanical Properties of Finger-Jointed Wood from Composite Utility Poles Made of Small Diameter Timber

Life cycle assessment of ACQ-treated Veneer Based Composite (VBC) hollow utility poles from hardwood plantation mid-thinning

Hardwood plantations are slow to mature with low financial returns in the early stage. Veneer Based Composite (VBC) products developed from mid-thinning may improve the industry’s profitability and win new markets. Due to the increasing demand for utility poles and the banning of native forests logging in Australia, VBC poles may become viable alternative to native hardwood poles. Alkaline copper quaternary (ACQ) preservative treated VBC pole was assessed using life cycle assessment (LCA) methodology. The manufacturing processes considered were based on the current technologies in Queensland. VBC pole life cycle stages assessed include mid-thinning, manufacturing, service-life, and disposal. Three end-of-life scenarios were considered: landfilling, incineration for energy recovery and recycling as particleboard. The functional unit used in this assessment is 1-metre-length pole with 115-mm internal-diameter and 15-mm wall-thickness. Global Warming Potential (GWP100), Fossil Depletion Potential (FDP), Acidification Potential (AP), Eutrophication Potential (EP), and Ecological Toxicity Potential (ETP) were quantified. Results indicated that landfilling and incineration outperform the recycling option. Incineration scenario performed slightly better under the GWP100 (0.3659kg-CO2-Eq), AP (2.12g-SO2-Eq), FDP (0.360kg-Oil-Eq) and EP (3.81g-PO4-Eq). Meanwhile, landfilling scenario had slightly less impact in ETP (12.32-CTUe). Despite generating valuable products, the burdens caused by secondary manufacturing and transportation overweighed credits earned from recycling. ACQ treatment, Phenol-formaldehyde (PF) resins production and transportation distances were identified as significant parameters affecting the final result. Sensitivity analysis indicated that EP was sensitive to change in ACQ consumption; ETP was affected by PF resin use while changing distances of transporting product affected GWP100, AP and FDP.

Veneer based composite hollow utility poles manufactured from hardwood plantation thinned trees

Australia’s utility pole network is aging and approaching its end of life. It is estimated that 70% of the 5million poles currently in-service nationally were installed within the 20years following the end of World War II and require replacement or remedial maintenance. Additionally, an estimated 21,700 high-durability new poles are required each year to support the expansion of the energy network. Utility poles were traditionally cut from native forest hardwood species. However, due to agreements which progressively phase out logging of native forests around Australia, finding new sources for utility poles presents a challenge. This paper presents the development of veneer based composite hardwood hollow utility poles manufactured from mid-rotation Gympie messmate (Eucalyptus cloeziana) plantation thinned trees (also referred to as “thinning”), as an alternative to solid hardwood poles. The incentives behind the project and benefits of the proposed products are introduced in the paper. Small diameter poles, of nominal 115mm internal diameter and 15mm wall-thickness, were manufactured in two half-poles butt jointed together, using 9 hardwood veneers per half-pole. The poles were tested in bending and shear, and experimental test results are presented. The mechanical performance of the hollow poles is discussed and compared to hardwood poles sourced from mature trees and of similar size. Additionally, the required dimensions of the proposed hollow pole to replace actual solid poles are estimated. Results show that the proposed product represents a viable technical solution to the current shortage of utility poles. Future research and different options for improving the current concept are proposed in order to provide a more reliable and cost effective product for structural and architectural applications in general.