Date of Award

Spring 5-9-2025

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Civil Engineering

First Committee Advisor

Luis Zambrano-Cruzatty

Second Committee Member

Bill Davids

Third Committee Member

Aaron P. Gallant

Abstract

This thesis presents the development and implementation of a novel non-conforming contact algorithm for robust and accurate simulation of rigid body-soil interaction within the Material Point Method (MPM) framework. Motivated by limitations in existing contact methods, particularly energy dissipation issues, this research introduces a dynamic distance field approach coupled with a non-linear penalty force. This combination effectively prevents interpenetration while accurately capturing the complex dynamics inherent in soil-structure interaction. The algorithm implementation within Anura3D, a state-of-the-art MPM software, is designed for versatility, accommodating complex geometries, multi-body contact, diverse material properties, and future extensibility to include structural deformation. A rigorous validation process employed a series of benchmark problems of increasing complexity. Beginning with a simple mass-spring system, comparisons with analytical solutions and the Finite Difference Method (FDM) confirmed the accuracy of the MPM implementation for both linear and non-linear spring behavior. The inclusion of damping further enhanced stability, mimicking realistic soil settling. A sliding block model facilitated parametric studies on damping ratio, material points, and mesh size, demonstrating the model’s consistency and stability across various configurations. The Oedometer test provided a more complex benchmark, with excellent agreement between MPM and FDM results validating the contact algorithm’s performance in compression scenarios. Mesh convergence and spring stiffness parameter studies further confirmed the method’s robustness and provided practical guidelines for parameter selection. Finally, a free-fall wall simulation demonstrated the algorithm’s ability to capture dynamic impact, replicating the behavior of the existing Bardenhagen contact algorithm in Anura3D and providing insights into soil deformation mechanisms. This research successfully addresses limitations of current contact approaches in MPM, offering improved energy conservation and a more realistic representation of soil-structure interaction. The developed algorithm provides a valuable tool for geotechnical engineers and researchers, enabling more accurate and efficient simulations of complex soil-structure interaction problems. Future work will focus on incorporating structural deformation into the framework, broadening its applicability to a wider range of engineering challenges.

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