Fatigue Reliability Evaluation Method for Steel Bridge Deck Based on Probabilistic Fracture Mechanics

Abstract

The present invention provides a fatigue reliability assessment method for steel bridge decks based on probabilistic fracture mechanics. The vehicle dynamic weighing (WIM) measured data is used to determine the probability distribution model of the random parameters of the vehicle load through statistical analysis, and the random sampling program is compiled to realize multiple Random traffic flow simulation of the lane, determine the stress influence surface of fatigue vulnerable details according to the finite element analysis of the three-dimensional beam section, and obtain the fatigue evaluation load spectrum and stress spectrum based on the influence surface loading; introduce the stochastic process and fracture mechanics The crack growth test of the sample and the preparation of a crack growth simulation program to quantify its model parameters; the fatigue failure limit state equation was constructed, and the time-varying law of the fatigue reliability of the structural details of the steel bridge deck was evaluated in combination with the reliability theory. This method provides a new idea for the refined fatigue assessment of complex steel bridge decks, and the assessment results can be used as an important basis for assessing the damage status of potential fatigue details and making maintenance decisions.

Description

technical field [0001] The invention belongs to the field of fatigue crack growth simulation and fatigue reliability analysis of steel bridge decks, and specifically relates to a method for evaluating the fatigue reliability of steel bridge decks based on probabilistic fracture mechanics, which is used to evaluate the typical performance of steel bridge decks under random traffic loads during service. The fatigue reliability of structural details provides a basis and reference for exploring the fatigue damage state and service safety of existing steel bridge deck structures and formulating corresponding management and maintenance strategies. Background technique [0002] Orthotropic steel deck is the preferred deck structure for the main girder of modern long-span and ultra-long-span steel bridges. However, under the coupling influence of multiple factors such as random traffic loads, structural characteristics, material properties, and manufacturing processes, fatigue crack...

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Problems solved by technology

[0005] In order to solve the problem that the traditional deterministic fatigue evaluation method ignores the randomness of the key influencing factors, and the reliability evaluation method based on the fatigue strength curve (S-N curve) cannot directly reflect the change of fatigue performance with the crack growth process, the present invention provides an accurate, efficient and The universal fatigue reliability assessment method for steel bridge decks based on probabilistic fracture mechanics quantitatively analyzes the structural details of steel bridge decks and the time-varying fatigue reliability of typical failure modes in the form of reliability indicators, so as to provide in-depth Provide an important reference for understanding the potential fatigue damage parts of the steel bridge deck, assessing the fatigue damage status, and formulating maintenance plans and decisions

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