The invention provides a multi-axial
fatigue damage evaluation method and device for a steel bridge
welding seam considering
welding residual stress, and relates to the technical field of fatigue strength analysis and service life prediction of a steel bridge structure. The method comprises the following steps: measuring three-dimensional
residual stress in a geometric transition area of a steel bridge
welding seam by adopting X rays, acquiring
heat distribution and surface
topography data in combination with
infrared thermal imaging and
structured light scanning, and realizing multi-
source data space alignment based on a unified coordinate
system; secondly, random disturbance is applied to the
residual stress, stress fluctuation in service is simulated, and a robustness weight
risk factor is constructed; the method comprises the following steps: constructing a bimodal deep neural network, adaptively fusing information of an
infrared thermal imaging image and a welding seam three-dimensional
topography image through an attention mechanism, training a fatigue risk regression model by taking a robustness weight
risk factor as a supervision
signal, completing prediction of risk factors at all positions, dividing low, medium and high risk levels based on a preset threshold value, and obtaining a fatigue risk prediction result. And accurate grading evaluation of the
fatigue damage of the welding seam is realized.