Mechanical Behavior of Damaged Strand Suspender with Asymmetric Broken Wires in Arch Bridges

Abstract:

A mechanical model is proposed to describe the behavior of a damaged strand suspender with asymmetric broken wires in this paper, and the relations between the coefficient of interwire friction, the external contact force between sheathing and wires, the affected length of the suspender with broken wires, and the remaining tensile force of the suspender are investigated. Results show that forces in the broken and unbroken wires of the suspender are not equal over the affected length, centered at the break, but are equal beyond. The unbroken wire strains within the affected length are not uniform and have maximum strains occurring in the unbroken wires adjacent to the broken wires, but the rest of unbroken wires are significantly associated with the forms of broken wires. The strain in the broken wire is zero at the wire break and increases exponentially with distance from the break. The strain in the unbroken wires is a maximum at the wire break and decreases exponentially with distance from the break. Within the affected length, the remaining prestress fraction approaches a lower limit, which is a little more than the loss of the crosssectional area of the suspender. Meanwhile, the stress redistribution of a damaged suspender with asymmetric broken wires is significantly affected by contact forces between sheathing and outer wires, and frictions between broken wires and king wires.