The 1999 AISC Specification for Structural Steel Buildings establishes two design equations for the web crippling limit state at the supports. However, investigators have suggested that the basis of these equations, which is based on an assumed collapse mechanism, is conservative especially for long bearing lengths. Most of the experimental studies conducted to validate those formulas have considered short span lengths and relatively small bearing-to-depth ratios. Therefore, a further investigation of the web crippling capacity of W-shape steel beams for larger span lengths and larger bearing-to-length ratios was undertaken.

The primary objective of this study is to analytically investigate the web crippling strength of W-shape steel beams for large bearing-to-depth ratios on large span beams, and to compare the results with the 1999 AISC LRFD web crippling design equation (K1-5b). The web crippling strength of W-shape steel beams was investigated by means of the finite element technique. The commercial finite element package ANSYS 6.0 was used to model the steel beams. Material nonlinearities, large deformation effects and initial geometric imperfections were taken into account in the finite element models.

The validation results shown that the finite element models closely predicted the ultimate load and web crippling failure mode shape of the tested beams. Conclusions based on the predictions of the finite element analyses and the current 1999 AISC end web crippling design equation (K1-5b) are presented in the study.