This paper proposes a novel bond model based on three-dimensional sphere discontinuous deformation analysis (SDDA) to simulate rockfall-flexible passive net interactions. At first, submatrices of the bond model added to the simultaneous equilibrium equations are derived. Then the relationship between elastic coefficient and spring stiffness for avoiding parameter calibration is built. And a failure criterion for breaking the bond between every two connected spheres is established. Four numerical tests are conducted to simulate the deformation and failure of a flexible passive net under the actions of forces and rockfall. The correctness, accuracy, and feasibility of the proposed bond model are verified by comparing the results with analytical solutions. Further, parameter sensitivity analysis is performed to investigate the influence of the anti-bending coefficient on computational stability and convergence, and to determine its reasonable value range. Finally, a simulation of flexible passive nets intercepting rockfalls on a mountain is carried out. Numerical performances show that the proposed bond model enables SDDA to properly simulate rockfall-flexible passive net interactions, providing a practical tool for rockfall mitigation in geotechnical engineering.

中文翻译：

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一种基于三维球体不连续变形分析的新型粘结模型，用于模拟落石-柔性被动网络相互作用

本文提出了一种基于三维球体不连续变形分析（SDDA）的新型粘结模型来模拟落石-柔性被动网相互作用。首先，导出添加到联立平衡方程中的键模型的子矩阵。然后建立弹性系数和弹簧刚度之间的关系以避免参数校准。并建立了破坏每两个相连球体之间键的失效准则。通过四次数值试验来模拟柔性被动网在力和落石作用下的变形和破坏。通过将结果与解析解进行比较，验证了所提出的键合模型的正确性、准确性和可行性。进一步进行参数敏感性分析，考察抗弯系数对计算稳定性和收敛性的影响，并确定其合理取值范围。最后，对山体上柔性被动网拦截落石进行了模拟。数值性能表明，所提出的粘结模型使 SDDA 能够正确模拟落石-柔性被动网络相互作用，为岩土工程中落石缓解提供实用工具。