Probabilistic Fields of Fatigue Crack Growth Rates of Puddle Iron Based on Huffman Local Approach

Abstract

<p>One key aspect related to structural integrity of bridges is the fatigue behavior of its materials and structural components. Generally, a fatigue crack initiates in zones where there is a concentration of stresses (geometric discontinuities, for example) and then it may propagate at an increasing growth rate leading to structural failure. Experimental campaigns have been performed in order to characterize the fatigue crack growth (FCG) behavior of these old metallic materials. More recently, several FCG models based on local approaches have been proposed. Huffman developed a strain energy density model based on Walker-like stress life and FCG behavior. The FCG process is assumed as successive crack re-initiations considering an elementary material block size. This model is used in this paper to predict the fatigue crack propagation of puddle iron material from a Portuguese centenary bridge. This model is combined with the generalized probabilistic fatigue model proposed by Correia in order to define probabilistic FCG fields.</p>