Study On Transverse-Low Speed Impact Performance Of Prestressed Steel Strand

As a common prestressed components,the steel strand has a wide range of applications,and its bearing capacity affects the safety of the whole structure,once it's been destroyed a large amounts energy will be released and cause damage or collapse to the whole structure.As a single axialpull bearing component,the transverse force performance of steel strand is often neglected,but in recent years,the steel strand has been frequently damaged by impact accident,and the mechanical properties of the steel strand subjected to impact can not be evaluated.The steel strand is made of a number of independent steel wires,the force of each steel wire is different when affected by the external load,the internal stress distribution of the filament is also complex.The fracture position and quantity of the strands are not same under the impact,and the damage forms caused by different impact conditions are also not similar.based on this,to understand the performance of steel strand affected by transverse impact,this paper has carried on the research through the experiment and the finite element simulation,mainly carried on the following work:The friction coefficient test of the steel strand material is carried out to provide finite element simulation parameters;The single wire drawing test is carried out to obtain the maximum load of the wire slip of the steel strand,bygettingthe friction coefficient determination and drawing load,we can study the internal contact load of the strand under the natural state.At last,the influence of the friction coefficient on the stress distribution of the strand under tensile effect is verified by the finite element model.(2)The whole tensile test is carried out to obtain the stress-strain constitutive relation curve of the steel strand under static tensile action,to provide the constitutive equation for the experiment and finite element simulation.To study the impact performance of the steel strand,impacted the steel strand with high quality and low speed,the energy and the prestress level are considered as the impact condition.The failure form and failure law of steel strand are summarized,and the residual strength of steel strand after impact is compared and analyzed.(3)The impact of steel strand is studied by finite element model,and the deformation and stress and strain distribution of steel strand under different impact energy are further understood.the transverse bearing capacity of steel strand is studied through the movementof steel strand and impact hammer,and the energy conversion and consumption in the impact process are carried out.By setting different coefficient of friction,The influence of the contact condition of strands on the impact performance is verified.