Theoretical and experimental study on the damage behavior of bolted joints under cyclic loads

This paper presents a quasi-static and dynamic experimental study on the damage behavior of bolted joints. It proposes a 7-parameter theoretical model to accurately describe the damage properties of bolted joints during both micro- and macro-slip stages under cyclic loads. Results from quasi-static experiments indicate that under the preload of 12.4 kN, a ratcheting effect is observed during the micro-slip stage, reflecting the cumulative plastic damage process at the bolted interface. The macro-slip force exhibits a linear decrease with increased loading cycles. In the initiation of macro-slip, energy dissipation exhibits unstable characteristics, manifested as an "S"-shaped curve in the energy dissipation-applied force relationship. The proposed model can well describe bolted joints' observed energy dissipation characteristics.