Fatigue and Fracture of Riveted Bridge Members

Abstract

Estimates of remaining fatigue life and development of rational maintenance strategies for riveted bridges are hindered by a lack of knowledge of their resistance to fatigue and fracture. This paper presents results of fatigue tests of three types of full‐scale riveted bridge girders. If stresses are calculated using net‐section areas, detail category European Convention for Construction Steelwork (ECCS) 71 American Association of State Highway Traffic Officials [(AASHTO)D] provides a reasonable estimate of fatigue strength of mildly corroded steel and wrought‐iron elements. Also, the maximum shear stress range in rivets should not exceed 14 ksi (100 MPa). Fracture properties of wrought iron are examined in tests of Charpy specimens and fatigue‐cracked plates. Fracture toughness of wrought iron may be low and consequently it is important to obtain data corresponding to the material employed in the bridge under assessment. If toughness is low, other factors that contribute to critical crack length (e.g., built‐in stresses, geometry, and loading) become important, since critical crack lengths may not be detectable under certain conditions. Finally, a two‐criteria approach for determination of critical crack lengths has been identified to be useful for civil engineering structures.