Dynamic Performance And Experimental Study Of CFRP Reinforced Flexible Cable Net Under Debris Flow Load Impact

Debris flow is a natural disaster characterized by suddenness,high flow velocity and strong destructive power,which occurs mostly in mountainous areas.Not only has it brought serious personal and economic losses to our country,but countries around the world have also been affected by natural disasters caused by mudslides.The most effective means of controlling debris flows is to set up a blocking system,including gravity blocking dams and flexible protective nets.In recent years,flexible protective systems have developed more and more rapidly,because they are widely used because of their high efficiency,light weight,and adaptability to mountainous terrain.However,it has been found in actual disasters that the existing flexible protection system usually suffers from structural failure under the impact of large stones,and because of its steel material,it is easily rusted during use,which weakens its proper.Therefore,based on the existing flexible protective net and flexible protective system,this paper takes the concept of flexible protection as the leading idea,and uses the excellent performance of carbon fiber reinforced composite material(CFRP)in the field of reinforcement,and applies it in the field of debris flow prevention and control.The flexible protective cable net system in this subject is reinforced by CFRP giving full play to its light weight,high strength and good corrosion resistance.Through 9 sets of static tensile test pieces,the change of static performance of steel cable after bonding carbon fiber cloth was studied,and found that the steel cable after reinforcement of carbon fiber cloth had a certain increase in yield strength,but the change of tensile strength was not obvious.The finite element software ANSYS/LS-DYNA was used to carry out numerical simulation analysis to study the dynamic response of single cable,combined cable and cable net after impacting carbon fiber cloth.It is found that in the impact process of single cable,cable or cable net,once the carbon fiber cloth reaches its ultimate stress failure,the stress of the carbon fiber cloth will be suddenly transmitted to the cable,resulting in a sudden increase phenomenon in the stress of the cable.In addition to the easy breakage of the carbon fiber cloth at the impact point,the carbon fiber cloth at the anchors at both ends is also prone to fracture failure.Finally,the impact test was carried out.After analyzing the test data and the phenomenon,it was found that the carbon fiber cloth had only a small amount of damage at the impact point under the impact of the 100 mm diameter steel ball.However,under the impact of 200 mm and 300 mm diameter steel balls,the tensile damage of the cable is more serious,which not only causes a lot of damage in the impact area,but also causes serious damage near the anchoring end.The displacement and strain increase with the increase of the impactor diameter,and the closer the impact point is to the measuring point,the larger the displacement peak and the strain peak;the acceleration generally shows that the acceleration of the lateral cable anchoring end is greater than other positions.The results are basically consistent with the results of the numerical simulation.Further explaining the influence of CFRP materials on the impact resistance of steel cables in actual situations,it provides a reference for the application of carbon fiber composite materials in this field.