Given that the material-wearing process is the key factor influencing the dynamic shear strength at the interface between the geomembrane (GMB) and nonwoven geotextile (NWGT), this study investigates the cyclic shear behavior of the GMB–NWGT interface from a microscale perspective using the three-dimensional discrete element method (DEM). The textured GMB is simulated with breakable asperities and the thermally bonded NWGT is generated by spatially randomly distributed fibers which could be stretched and untangled. The established model is validated against the experimental data. The wearing process during cyclic loading is evaluated by quantifying the embedded depth of GMB asperities and fiber breakage within NWGT. The simulation results demonstrate that the maximum asperity embedment (inter-embedding effect), affected by the normal stress and displacement amplitude, induces the hook and loop interactions between asperities and fibers (inter-locking effect), accounting for the cyclic shear resistance at the interface. The inter-locking effect dominates the strain-hardening behavior of the GMB–NWGT interface when the percentage of inter-fiber bond breakage is less than 22% and the maximum asperity embedment ratio is lower than 60%; otherwise, the inter-embedding effect dominates the strain-softening behavior of the interface.

中文翻译：

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使用 DEM 对土工膜-土工布界面循环剪切行为进行微观分析


鉴于材料磨损过程是影响土工膜 （GMB） 和非织造土工布 （NWGT） 界面动态剪切强度的关键因素，本研究使用三维离散元法 （DEM） 从微观角度研究了 GMB-NWGT 界面的循环剪切行为。纹理 GMB 模拟了易碎的凹凸，热粘合的 NWGT 由空间随机分布的纤维产生，这些纤维可以被拉伸和解开。根据实验数据验证了所建立的模型。通过量化 NWGT 内 GMB 凹凸和纤维断裂的嵌入深度来评估循环载荷期间的磨损过程。仿真结果表明，受法向应力和位移幅值影响的最大凹凸度嵌入（嵌入效应）会引起凹凸度和纤维之间的钩环相互作用（互锁效应），从而解释界面处的循环剪切阻力。当纤维间键断裂百分比小于 22% 且最大凹凸嵌入率低于 60% 时，互锁效应在 GMB-NWGT 界面的应变硬化行为中占主导地位;否则，inter-embedding 效应将主导界面的应变软化行为。