Study on failure mode and parameter influence of epoxy coating steel strand with the impact action

Epoxy coated steel strand (ECSS) has good durability and anti-corrosion capacity. It is expected to be used in cable-stayed bridges which needs to be designed for a life of 100 years or more. Based on the finite element method, the impact resistance of ECSS was studied by numerically simulation. The friction coefficient between the wires of ECSS was calculated through bond stress test and theoretical analysis. The finite element simulation of the specimen with the same size as that in the experiment was carried out to study the failure and damage fracture evolution law. The effects of impact velocity, friction coefficient between the wires and other parameters on the dynamic properties of ECSS were also analyzed. By comparing the test data with the simulation results, the evolution law of the impact resistance of ECSS under different working conditions was revealed. Main conclusions: the friction coefficient of ECSS between the wires was 0.48, and the contact load between the wires was basically linear with its length; In the range of 7D-14D lay length, the mutual work behaviors between the wires was better when the lay length was larger. When the applied prestress was less than 0.15fu, itwas beneficial to improve impact resistance. The increase of the friction coefficient between the wires will reduce the impact failure time and have an adverse effect on its overall impact resistance capacity.