arXiv subjects

Biswajeet Rath

Publications and source records attributed to Biswajeet Rath.

3 recordsLinked to original sources

arXiv2025

A Phase Field Formulation of Frictional Sliding Contact for 3D Fully Eulerian Fluid Structure Interactions

Frictional sliding contact in hydrodynamic environments can be found in a range of engineering applications. Accurate modeling requires an integrated numerical framework capable of resolving large relative motions, multiphase interactions, and nonlinear contact responses. Building on our previously developed fully Eulerian fluid structure formulation, we introduce a phase field based formulation for dynamic frictional contact in 3D. Contact detection is achieved via the overlap of diffuse interfaces of colliding solids. The normal contact response is defined as a volumetric body force proportional to the overlap parameter, while the tangential response is computed using the Coulomb friction model. The direction of the friction forces are derived by projecting phase-averaged relative velocities onto the local tangent plane of colliding bodies. This proposed unified treatment enables the computation of both normal and frictional forces within a single momentum balance equation, avoiding separate velocity fields for individual solids. We present several test cases with increasing complexity to verify and demonstrate our proposed frictional contact model. Verification against the Hertzian contact problem shows excellent agreement with the analytical solution, with errors below $3\%$ in the traction profile. In the sliding block benchmark, the computed displacement profiles closely follow the analytical solution for point-mass systems across multiple friction coefficients. The ironing problem demonstrates stable force predictions under finite deformation, with normal and tangential forces matching kinetic friction laws. The robustness and scalability of the proposed formulation are further demonstrated through a representative ship ice interaction scenario with free surface and frictional sliding effects.

physics.comp-ph↗

arXiv2024

An Efficient Phase-field Framework for Contact Dynamics between Deformable Solids in Fluid Flow

Elastic contact in hydrodynamic environments is a complex multiphysics phenomenon and can be found in applications ranging from engineering to biological systems. Understanding the intricacies of this coupled problem requires the development of a generalized framework capable of handling topological changes and transitioning implicitly from FSI conditions to solid-solid contact conditions. We propose a mono-field interface advancing method for handling multibody contact simulations in submerged environments. Given the physical demands of the problem, we adopt a phase-field based fully Eulerian approach to resolve the multiphase and multibody interactions in the system. We employ a stabilized finite element formulation and a partitioned iterative procedure to solve the unified momentum equation comprising solid and fluid dynamics coupled with the Allen-Cahn phase-field equation. We introduce a contact force approach to handle smooth elastic-elastic and elastic-rigid contact based on the overlap of the diffused interfaces of two colliding bodies. We propose a novel approach to extend the model for multibody contact simulations while using a single phase-field function for all the solids. The method is based on updating the solid boundaries at every time step and checking for collisions among them. The developed approach eliminates the need to solve multiple phase field equations and multiple strain equations at every time step. This reduces the overall computational time by nearly $16\%$ compared to a multi phase-field approach. The implemented model is verified for smooth dry contact and FSI contact scenarios. Using the proposed framework, we demonstrate the collision dynamics between multiple bodies submerged in an open liquid tank.

physics.flu-dyn↗

arXiv2022

An Interface-Driven Adaptive Variational Procedure for Fully Eulerian Fluid-Structure Interaction via Phase-field Modeling

In this paper, we present a novel interface-driven adaptive variational procedure using a fully Eulerian description of fluid-structure interaction. The proposed fully-Eulerian procedure involves a fixed background unstructured mesh on which the fluid-structure interface is treated implicitly. We model the fluid-structure interaction by the phase-field finite element formulation relying on a partitioned staggered integration of the convective Allen-Cahn equation with the unified momentum equation for both solid and fluid dynamics. We employ the positivity preserving variational scheme for a bounded and stable solution of the Allen-Cahn phase-field equation. To evaluate the solid stresses, the left Cauchy-Green deformation tensor is convected at each time step to trace the evolution of the solid strain in the Eulerian reference frame. We utilize the residual based error indicators and the newest vertex bisection algorithm for the adaptive refinement/coarsening of the unstructured mesh. The proposed nonlinear adaptive partitioned procedure restricts the coarsening step to the last non-linear iteration while simultaneously ensuring convergence properties of the coupled governing equations. We perform a detailed convergence and accuracy analysis via two benchmark problems namely, the pure solid system and a coupled fluid-solid system with an interface in a rectangle domain. We next systematically assess the performance of the adaptive procedure in terms of conservation properties for the increasing complexity of problems. Finally, we demonstrate our fully-Eulerian interface-driven adaptive FSI model to simulate the contact and bouncing phenomenon between an elastic solid and a rigid wall.

physics.comp-ph↗