RELIABILITY OF WOOD UTILITY POLES UNDER STOCHASTIC WIND LOAD AND MATERIAL CONSIDERING KNOTS

M.B. ROSALES; D. A. GARCIA; L. V. GONZÁLEZ DE PAZ

La Plata

Congreso; XXIII Congreso de Métodos Numéricos y sus Aplicaciones ENIEF 2017; 2017

Asociación Argentina de Mecánica Computacional AMCA

Wood utility poles are simple structures used in power networks and their failure may producea significant impact on their reliability as well as economic consequences. Wind loads are one of themain causes of damage in wood utility poles. The present study addresses the dynamic behavior ofArgentinean Eucalyptus grandis wood poles with uncertain material properties under stochastic windload. Regarding the material, the lengthwise variability of the Modulus of Elasticity (MOE) and thesecond moment of area are simulated through the Weak Zone (WZ) model taking into account the knotspresence. The stochastic wind velocity field is derived using the Spectral Representation Method (SRM)considering temporal and spatial correlation. Then, the wind load is obtained under the considerationsof the Argentinean standard CIRSOC 102. The governing equations are discretized through the FiniteElement Method (FEM). The stochastic analysis is performed by means of Monte Carlo Simulations(MCS). In this study, displacements are evaluated such that a percentage of damage is found for eachwind velocity. Fragility curves are a useful means to evaluate the failure probability of the poles for adefined failure mode, under a given range of demand, here the wind load. The WZ model results arecompared with other MOE models previously developed (as a random variable and as a random fieldthrough the Non Gaussian Karhunen-Loève Expansion). Also, confidence bands of the fragility curvesare obtained for 95% of confidence.