ABSTRACT
Linear and Nonlinear finite element (FE) models of the steel H-pile specimens used in the experimental test set up are developed using the computer program ANSYS to identify potential problems that may be encountered during testing and to improve the test apparatus. First, linear FE models of the steel H-pile specimens are built to determine maximum stress concentrations occurring in the HP sections and the steel base fixture used for fixing the pile to the testing frame. From these linear analyses results; the locations of stress concentrations in the HP sections are identified. Using these results, the test set up is modified to decrease the stress concentrations. Then, nonlinear FE analyses of the steel H-pile specimens are repeated on the modified specimen model to observe the distribution of stresses and strains in the steel HP sections and the steel base fixture. Then, low cycle fatigue tests are conducted to investigate the fatigue life of steel H-piles subjected to thermal induced cyclic strains/displacements. In the experimental part, HP220x57 pile specimens are tested to estimate the low cycle fatigue life of steel H-piles as a function of large flexural strain cycles with various amplitudes. Using the FEM, comparisons between FE model predictions and experimental test results are made in terms of fatigue life in the steel H-pile specimens. Consequently, it is shown that nonlinear FEMs of the steel H-pile used in the experimental part should be used to identify potential problems that may be encountered during testing and to improve the test apparatus if necessary.
