Penetration-free Solid-Fluid Interaction on Shells and Rods

2025-05-18

AI Summary

This work addresses the geometric penetration issue in fluid–thin elastic solid (e.g., shells, slender rods) coupling simulations. The proposed penetration-free fluid–structure interaction method formulates a unified optimization framework that jointly enforces solid elastic energy, fluid incompressibility, damping, and inertial dynamics, while explicitly incorporating barrier constraints to guarantee strict non-penetration. A novel explicit positional constraint mechanism enables generalized distance evaluation between implicit fluid interfaces and Lagrangian solids of arbitrary codimension. Coupled with a volume-preserving strategy—combining level-set representation and value adjustment—it significantly improves volumetric conservation accuracy. The method robustly handles complex interactions including topological changes, bouncing, splashing, sliding, rolling, and floating. It achieves high visual fidelity while substantially enhancing robustness and physical accuracy in simulating fine-scale coupled structures.

Technology Category

• Search and Optimization: Sampling/Simulation-based Search
• Computer Vision: Low Level & Physics-based Vision
• Constraint Satisfaction and Optimization: Mixed Discrete/Continuous Optimization

Application Category

• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Systems and Infrastructure for Web, Mobile and WoT: Virtualization and resource management in Web systems and infrastructures

Abstract

We introduce a novel approach to simulate the interaction between fluids and thin elastic solids without any penetration. Our approach is centered around an optimization system augmented with barriers, which aims to find a configuration that ensures the absence of penetration while enforcing incompressibility for the fluids and minimizing elastic potentials for the solids. Unlike previous methods that primarily focus on velocity coherence at the fluid-solid interfaces, we demonstrate the effectiveness and flexibility of explicitly resolving positional constraints, including both explicit representation of solid positions and the implicit representation of fluid level-set interface. To preserve the volume of the fluid, we propose a simple yet efficient approach that adjusts the associated level-set values. Additionally, we develop a distance metric capable of measuring the separation between an implicitly represented surface and a Lagrangian object of arbitrary codimension. By integrating the inertia, solid elastic potential, damping, barrier potential, and fluid incompressibility within a unified system, we are able to robustly simulate a wide range of processes involving fluid interactions with lower-dimensional objects such as shells and rods. These processes include topology changes, bouncing, splashing, sliding, rolling, floating, and more.

Problem

• Simulate fluid-thin solid interaction without penetration
• Enforce incompressibility and minimize elastic potentials
• Measure separation between implicit surfaces and Lagrangian objects

Innovation

• Optimization system with barriers prevents penetration
• Adjusts level-set values to preserve fluid volume
• Unified system integrates solids and fluids robustly