Work

Coupled Eulerian-Lagrangian finite element models of static and percussive excavation mechanics of lunar regolith and simulants

Year: 2026

Type: article

Abstract: As human and robotic exploration of extraterrestrial rocky bodies advances, excavation of planetary regolith becomes a critical operation for in situ resource utilization, infrastructure emplacement, and science. Accurate modeling of excavation forces is essential for developing efficient excavation systems and interpreting regolith mechanical properties from tool-regolith interaction data. This study evaluates the novel application of coupled Eulerian-Lagrangian finite element models as a, conceptually straightforward, and well-formulated approach for simulating excavation in lunar regolith simulants. This study developed coupled Eulerian-Lagrangian finite element models to simulate static and percussive (force reduced) excavation experiments in JSC-1A lunar regolith simulant across low, medium, and high relative densities and with varying excavation depth. Forward models reproduced general excavation force trends but overpredicted mean forces, which can be remedied by accounting for the strain softening and consolidation hardening properties that are needed to accurately simulate lunar and planetary regolith mechanics. Inverse modeling using a grid search demonstrated that the models developed here can estimate regolith mechanical property values when models are calibrated to either mean or maximum excavation forces. Percussive excavation simulations captured reductions in excavation force but underpredicted the magnitude of force reduction due to the absence of strain rate-sensitive softening. High frequency percussive simulations revealed numerical instabilities requiring improved meshing techniques. Simulations under lunar gravity of a replica Surveyor III Soil Mechanics Surface Sampler scoop highlight the flexibility of the developed models in simulating complex, realistic tool paths and simulation of a reduced gravity environment and present key considerations for extrapolating results from laboratory testing to reduced gravity environments. Overall, coupled Eulerian-Lagrangian finite element models show promise for modeling lunar and planetary regolith-tool interactions, but further work is needed to enhance simulation fidelity.

Source: Acta Astronautica

DOI: 10.1016/j.actaastro.2026.06.050

Authors: Jared M. Long-Fox, Robert P. Mueller, Kris A. Zacny, Daniel T. Britt

Institutions: University of Central Florida, Kennedy Space Center, Honeybee Robotics (United States)

Language: English

Topic: Soil Mechanics and Vehicle Dynamics

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,350

Funders: National Aeronautics and Space Administration, Solar System Exploration Research Virtual Institute, Space Technology Mission Directorate