Study On The Mechanical Properties And Dissipation Capacity Of Ring-Brake Energy Dissipation In Passive Flexible Protection

The geographic in China, especially in the western region is very vast and complex, thus landslides, collapse, rockfall and other natural disasters often happen in these area. For the prevention of such disasters, academics and engineers have proposed a variety of measures and methods. Passive flexible protection, which is widely used, is one of the methods among them. However, not all the engineers has systematic knowledge to the composition, characteristics and basic principles of passive flexible protection. Coupled with its own complex structural behavior, there is little research on it.Because of the complexity of the transmission property under impact to passive flexible protection, and for better application for it, this paper take the ring-break energy dissipater and passive flexible protection for example. Theoretical analysis and numerical simulation method are combined to study the mechanical properties of the ring-break energy dissipater and its buffer, including the follo wings:(1) Using theoretical analysis, the mechanical properties of ring-break energy dissipater under dynamic loading is studied, and the energy-consuming principle is analyzed. Based on the analysis, the main factors influencing the performance of ring-break energy dissipater is summarized. By the method of structural mechanics, the approximate calculation of the prestress between steel pipe and aluminum sleeve is derived.(2) By finite element analysis software ANSYS/LS-DYNA, the ring-break energy dissipater, the ring-break energy dissipater model is established. And the load-displacement curves of ring-break energy dissipater under different pressures, aluminum sleeve length, pipe thickness and pipe diameter is analyzed. Due to the result, the load-displacement curve is carried out and a plan to improve the design of ring-break energy dissipater is proposed.(3) Taking an actual passive flexible protection prototype as example, the overall model of the pressure flexible protection without ring-break energy dissipater, with normal ring-break energy dissipater, and with improved ring-break energy dissipater are established. Based on ANSYS/LS-DYNA, the dynamic response of the three finite element models under different impact energy and impact position were analyzed. The results show that:The ring-brake energy dissipater can enhance the flexibility of the passive flexible protection and improve the performance of the site of action, meanwhile can also significantly improve the energy dissipation capacity of the passive flexible protection. Moreover, compared with normal ring-break energy dissipater, the improved ring-break energy dissipater can further improve energy capacity of passive flexible protection prototype, and itself can take on more energy. The comparative analysis of the numerical results,for our next experiment design to calibrate the numerical model and to identify the governing characteristics of the components, supply references.