Fatigue Behavior of Welded Aluminum Light Pole Support Details

A study of the behavior of two types of welded aluminum light pole support details was conducted. Twenty nine full-scale samples were tested to determine fatigue life, and included 19 poles with cast shoe base socket connections along with 10 through plate socket connection details. The primary objective of this investigation was to compare the test results with current fatigue design provisions, and to determine the applicable design category or develop new lower bound stress-life (S-N) curve(s), as appropriate. To augment the tests, parametric studies of both detail types were conducted using the finite-element method. Parametric studies included the effect of the light pole tube radius to thickness ratio, base plate thickness, and fillet weld dimensions on the local stresses adjacent to the weld toe area. Residual stresses, determined through the application of the hole drilling technique, assisted in the understanding of the fatigue test results.