A Uni‐Axial Damage Model for Axial Steel Braces in Large‐Span Structures Under Cyclic Loading Protocol

ABSTRACT This study addresses the need for an accurate damage model to represent the nonlinear degradation behavior of steel assemblies under axial cyclic loading. The proposed model is developed based on the theory of lumped damage mechanics (LDM) and structural mechanics, simplifying buckling and associated damage by focusing on plastic hinge effects in the central region of axial steel members while treating the rest as elastic beams. The model's predictions were validated against experimental results, demonstrating its capability to accurately forecast hysteresis curves, energy dissipation, and the onset of buckling. The findings indicate that the model effectively captures the nonlinear degradation of strength and stiffness in axial steel members, including phenomena such as compressive buckling‐induced deterioration, tensile yielding, the Bauschinger effect, and stiffness degradation. These results underscore the model's potential applicability in practical engineering scenarios, offering a computationally efficient alternative to traditional finite element methods for analyzing large‐span bridges and grid structures.