GeoSlice-MGN: Analysis-Guided Geometric Routing for Impact Response Prediction in Realistic Structures

Localized impact on complex structures produces high-gradient responses near the impact region and long-range structural coupling. Predicting these responses requires effective representations of loading position, structural boundaries, and local mesh geometry. We examine these geometric dependencies through finite-plate mechanics. Modal response analysis shows the roles of impact-relative and structure-relative positions. Analysis of bending and stretching strains shows that local spatial variations remain closely related to neighborhood directions and distances under finite deflection. Based on these relationships, we propose GeoSlice-MGN, which uses impact-relative geometry and bounding-box-relative position to modulate content-driven node-to-slice assignment. This makes load–structure geometry directly available to global routing in addition to its role in node features. The model retains local MeshGraphNet propagation before and after global interaction and augments slice states with relative soft occupancy. We also publicly release AutoPanelImpact, an open benchmark of 1,500 parameterized nonlinear impact cases on three real automotive floor panels, with paired displacement and stress fields under varying impact conditions. GeoSlice-MGN achieves the lowest average error on all six displacement–stress test metrics across the three panels. Experiments on BumperBeam and Plasticity further evaluate its applicability to coupled-field collision and deformation-sequence prediction.