AI 中文总结
研究半无限地基中移动荷载波传播和土-结构相互作用问题，提出2.5D NURBS追踪无限元方法，通过耦合有限/无限元方案，利用等几何分析离散近场，张量积表示外部，能处理多种复杂情况，提供几何一致且高效的处理方法。
AI 中文摘要
对于几何形状和材料特性沿传播方向近似不变的移动荷载问题，2.5D分析以低于全三维离散化的成本保留三个位移分量。本文提出一种2.5D非均匀有理B样条（NURBS）追踪无限元方法（NBIEM），用于线性粘弹性半无限岩土介质中的波传播，该方法被公式化为一种耦合有限/无限元方案。有界近场通过等几何分析离散，外部由边界NURBS基和可允许的出射或衰减指数径向函数的张量积表示。两个子域共享相同的NURBS追踪空间和控制点自由度，无需投影或砂浆变量即可强制位移连续性。对于选定的径向函数，通过封闭形式的径向矩评估远场刚度和质量贡献，消除有限径向截断和径向积分。封闭形式的半空间解验证了亚瑞利、超剪切但亚压缩和超压缩移动荷载工况下的位移和应力频率响应函数。低频研究评估了对径向参数和人工边界位置的敏感性。额外测试检验了复值响应精度、相位保真度、计算成本以及默认S波通知的外部实现的频率相关工作范围。对层状介质、轨道-路基系统和埋地结构的应用证明了处理非均质材料、多面片配置、弯曲界面和覆盖深度相关岩土响应的能力。该框架为半无限域中移动荷载波传播和土-结构相互作用提供了几何一致且计算高效的处理方法。
英文摘要
For moving-load problems whose geometry and material properties are approximately invariant along the traveling direction, 2.5D analysis retains three displacement components at lower cost than full three-dimensional discretization. We present a 2.5D Non-Uniform Rational B-spline (NURBS)-trace infinite-element method (NBIEM), formulated as a coupled finite/infinite-element scheme, for wave propagation in linear viscoelastic semi-infinite geotechnical media. The bounded near field is discretized by isogeometric analysis, while the exterior is represented by tensor products of the boundary NURBS basis and admissible outgoing or evanescent exponential radial functions. Both subdomains share the same NURBS trace space and control-point degrees of freedom, enforcing displacement continuity without projection or mortar variables. For the selected radial functions, far-field stiffness and mass contributions are evaluated through closed-form radial moments, eliminating finite radial cutoff and radial quadrature. Closed-form half-space solutions verify displacement and stress frequency-response functions in sub-Rayleigh, super-shear but sub-compressional, and super-compressional moving-load regimes. Low-frequency studies assess sensitivity to radial parameters and artificial-boundary placement. Additional tests examine complex-valued response accuracy, phase fidelity, computational cost, and the frequency-dependent working range of the default S-wave-informed exterior realization. Applications to layered media, track--subgrade systems, and buried structures demonstrate the ability to handle heterogeneous materials, multi-patch configurations, curved interfaces, and cover-depth-dependent geotechnical responses. The framework provides a geometrically consistent and computationally efficient treatment of moving-load wave propagation and soil--structure interaction in semi-infinite domains.
DOI：10.1016/j.compgeo.2026.108515
