A MEMBRANE EQUIVALENT METHOD FOR MECHANICAL BEHAVIOR OF ORTHOGONAL STEEL WIRE RING NET

The orthogonal steel ring net widely used in rockfall protection engineering has complex nonlinear mechanical behavior. A membrane equivalent simulation method is proposed because of the low computational efficiency of a circular beam model. The loading test of a ring net was carried out, the P-Δ characteristics of the specimens were studied, the orthogonal mechanical characteristics of the ring net was analyzed, and the formation mechanism of the orthogonal tension band was revealed. Based on the principle of the shortest force transfer path, the membrane analytical model of the orthogonal tension band loaded out of plane loading was constructed, the stress-strain relationship of membrane was derived, thereby the membrane FEM model loaded out of plane loading was established. The results showed that membrane with exponential strengthening elastoplastic constitutive model can accurately recur the mechanical behavior of a steel ring net. Compared with the test results, the relative errors of the membrane ultimate force, of the displacement, and of the energy dissipation capacity were less than 10%. In addition, the impact responses obtained by impact FEM model established by the equivalent method was in a good agreement with the test results of existing literatures, and the peak acceleration relative error was 4.3%. Finally, based on the impact FEM model, the calculation efficiency of the equivalent model was compared with that of the circular beam model. The calculation efficiency of the equivalent method can be increased by more than 10 times.