A Damage Index-Based Evaluation Method for Predicting the Ductile Crack Initiation in Steel Structures

Abstract

This article presents a damage evaluation method for predicting ductile crack initiation in steel bridge piers. In the proposed method, a damage index is introduced to evaluate ductile crack initiation. Seventeen different analytical models, including steel columns and beam-column connections in steel bridge pier frames, are created based on the shell element model, which takes local refined meshing into account. The plastic strain and damage index at strain concentration location are calculated. Moreover, effects of welded joint models, extension part, loading patterns and cross-section parameters are considered and discussed. Comparisons between experimental and analytical results show good prediction of ductile crack initiation. Meanwhile, the present method realizes prediction of ductile crack initiation at structural component level.

Keywords:

• Steel Bridge Pier
• Ductile Crack Initiation
• Shell Element Model
• Damage Index
• Plastic Strain

Acknowledgments

The study is supported in part by grants from Japan Science and Technology Agency for “Evaluation and Mitigation of Environment Impacts of Earthquake and Typhoon Disaster on Urban Area and Infrastructures” (Project Title: Refined Analysis and Damage Control of Earthquake Disaster Impact on Bridge Structures), under the Strategic Japanese-Chinese Cooperative Program on Science and Technology (S&T) for Environmental Conservation and Construction of a Society with Less Environmental Burden. Besides, the second author would like to thank to the Daiko Foundation for the financial assistance.