The analysis of fatigue resistance of bridge structures made of aluminum alloys

Abstract

Introduction. The author has developed a method for the fatigue resistance analysis of bridge structures made of aluminum alloys subjected to polycyclic loading. The author suggests that this method should be introduced into the currently enhanced regulatory documentation focused on the analysis of highway bridges made of aluminum alloys.Materials and methods.The method is based on the results of integrated laboratory testing of a number of aluminum alloys 1915T, AD35 T1, 1565hM, EN AW-6082 T6 that have good prospects in terms of the production of bridge structures. Physical-mechanical and fatigue characteristics were identified in the course of the static testing of specimens of these alloys before the fatigue cracking at different values of the cycle asymmetry coefficient. The theoretical fundamentals of the method stem from the domestic research on the fatigue resistance analysis of steel structures and foreign regulatory materials on the fatigue resistance analysis of bridge structures made of aluminum alloys.Results. The reliability of the new method was verified in the course of static and fatigue testing of a full-scale pedestrian bridge made of 1915T alloy and orthotropic plates made of EN AW-6082 T6 alloy, designed by NRU MGSU and manufactured by the Russian plants GS-Reserve, KraMZ and Sespel using advanced innovative technologies of extrusion and friction stir welding. Discrepancies between the experimental findings and the results of the analysis, made pursuant to the proposed methodology, are within 5-20 %.Conclusions. The proposed method can also be applied to other types of structures made of aluminum alloys, such as tanks, pipelines, high-rise structures, and other items that are subject to multiple cyclic effects.

Keywords

• bridge
• aluminum alloy
• bearing structure
• fatigue resistance
• fatigue strength
• methodology of analysis
• specimen testing
• stress