COMPARISON OF FAILURE CRITERIA OF A SLENDER WOOD STRUCTURE UNDER STOCHASTIC AND QUASI-STATIC WIND LOADS

LAURA GONZÁLEZ DE PAZ; MARTA B. ROSALES

Santa Fe

Congreso; ENIEF 2019; 2019

AMCA-UNL

A stochastic model of a wood pole under wind loads is addressed in order to study its failureunder different criteria. In order to evaluate wind loads on a structure, the Argentine standard CIRSOC102-2005 proposes simplifications that take into account the effects of shape, location and dynamics ofa load variable in time, resulting in an equivalent quasi-static action, which simplifies the strength anddeformations assessment of a given structure. However, if a temporal and spatial varying record of thewind load is considered in detail, the results should be comparable to those obtained with the standardload. The structural model consists of a wood utility pole with one end embedded in the ground andthe other end free, with deterministic geometry and material properties values. The pole is subjectedto a wind load along its length. The stochastic dynamic wind load as a temporal function derived froma Power Spectral Density Function using the Spectral Representation Method and taking into accountspatial and temporal correlations. The structural model is discretized with FEM and the realizations areanalyzed with Monte Carlo method. In the study, the maximum displacement at the tip is assumed as thefailure threshold. This work seeks to explore results from different failure criteria for dynamic loads andto compare them with the results of a pole under quasi-static deterministic wind load. The criteria are thefirst passage, the dwell time above the failure threshold, the extreme values distribution, the crossing rateand the cumulative proportion of displacements above the threshold of all the realization. A comparisonis carried out by means of the fragility curves to assess the suitability of each approach.