Non-linear analysis of cable networks by FEM and experimental validation

Abstract

This work studies the analysis of the resistant capacity of cable nets for the stabilization of slopes. Two tests have been carried out, one with a distributed longitudinal load and the other with distributed transversal load, in order to simulate in situ the working conditions of these systems. Tensile tests were also carried out on the cable elements of the network in order to obtain the non-linear mechanical properties. On the one hand, the proposed numerical procedure uses the finite element method (FEM) and it takes into account the material and geometrical non-linearities due to the geometrical change in the cable net substructure. On the other hand, the contour (boundary) beam is modelled by linear beam elements with contact between them. The numerical results of the longitudinal and cross tests were simulated for different geometrical configurations, generating convergent results with respect to strain and resistance, which permit the extrapolation from tested cable nets to untested simulated cable nets, maintaining a basic configuration of constant parameters. The laboratory tests only provide information about the strain and maximum resistance, but they do not establish a relationship between the values of stresses of each net element. These data have been obtained through the computational simulation by FEM. A reliable model of the interaction of the flexible contour beam with the cable network enables the achievement of more efficient solutions in the design analysis. Finally, we compare the structural behaviour of the numerical and experimental results by means of the equivalent elastic modulus and the equivalent Poisson ratio. Excellent agreement between the predicted results by FEM and test observations was found. Besides, conclusions and suggested procedures of calculation applied on the cable networks are given and numerical models to evaluate the stability of the slope protection systems are presented.

Keywords:

• finite element modelling
• wire mesh and cable net slope protection system
• material and geometrical non-linearities
• soil stabilization
• erosion control

2000 AMS Subject Classification :

• 74S05
• 74C05
• 35J60

Acknowledgements

We gratefully acknowledge the financial support provided by the Construction Technology Research Group (GITECO) at the University of Cantabria, Malla Talud Cantabria Ltd. (MTC) and SODERCAN. We thank Swanson Analysis Inc. for the use of ANSYS University Intermediate program. We also thank the Construction and Production Engineering Department of the University of Oviedo for the computational support.