Residual ultimate strength of structural members with multiple crack damage

This paper highlights the importance of residual ultimate strength in aging structures with multiple cracking damage and suggests simplified models for predicting the ultimate strength of multi-cracked structural members. Nonlinear finite element methods are employed to investigate the residual ultimate strength characteristics of these members when they have both a ‘lead crack’ and several ‘disturbing cracks.’ The link-up mechanism between lead and disturbing cracks at the plastic zones in terms of the ligament is illustrated. The effects of the location and size of the disturbing cracks when the lead crack is dealt with as a primary parameter of influence are investigated. It is found that when these disturbing cracks are near the lead crack, they reduce the ultimate strength of the structural members. However, their effect is negligible when they are located in a low-stress region of these members. A number of important insights drawn from the study presented herein are documented.