RANDOM FIELD OF THE MODULUS OF ELASTICITY CONSIDERING KNOTS: APPLICATION TO WOOD UTILITY POLES

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

San Miguel de Tucuman

Congreso; XII Congreso Argentino de Mecánica Computacional MECOM 2018; 2018

Asociación Argentina de Mecánica Computacional AMCA

Wood utility poles are simple structures used in power networks and their failure can produce a significant impact on their reliability as well as economic consequences. The presence of knotsis known to be the main source of the lengthwise variability and reduction in bending strength and stiffness in wood elements. Other authors have studied this variability and developed Modulus of Elasticity(MOE) distribution models for sawed wood elements, like beams. The aim of this work is to determine whether the aforementioned models, originally developed for sawn wood beams, can be appliedto a wood structure without sawing such as wood utility poles. Load-displacement curves and naturalfrequencies of the poles were obtained from static and dynamic test, respectively. A visual survey wasalso carried out to record geometry data, knot dimensions and location in the poles. Numerical modelsconsidering the surveyed geometry and the presence of knots are used. With this approach, the MOE random field is simulated through a weak zone model that accounts for knots. The governing equations arediscretized through the Finite Element Method (FEM). The stochastic analysis is performed by means ofMonte Carlo Simulations (MCS). Then, experimental data (displacements and natural frequencies) arecompared with numerical results in order to determine whether the models developed for sawn beamscan be applied to wood utility poles.