Development of Continuum-Based Liquid Sloshing Algorithms for Multibody System Dynamics

Liquid sloshing is an important phenomenon that has a significant impact on the dynamics and stability of highway, rail, marine, and aerospace transportation systems. Hazardous material accidents, which result in significant economic loss, environmental contamination, loss of lives, and property damage, can be avoided or significantly reduced through better understanding of the liquid sloshing effects. Liquid sloshing can produce significant impact forces as the results of the interaction with containers and/or tank cars. In order to study the effect of liquid sloshing on vehicle dynamics, multibody system (MBS) algorithms have to be integrated with a liquid sloshing solution technique. This thesis aims at contributing to the development of the first generation of continuum-based liquid sloshing computational algorithms for modeling complex motion scenarios, developing safety guidelines, and accurate accident reconstructions. In order to overcome the challenges and limitations of existing liquid sloshing analysis tools, a total Lagrangian non-incremental liquid sloshing model based on the finite element (FE) absolute nodal coordinate formulation (ANCF) was recently proposed. The objective of this thesis is to use this new approach to accurately evaluate, both qualitatively and quantitatively, the effect of liquid sloshing when vehicles experience large displacements including finite rotations. In this thesis, the new total Lagrangian ANCF liquid sloshing solution procedure is validated and verified using benchmark problems. Another contribution of this thesis is to quantify and evaluate the effect of turbulence on the average nominal motion of the fluid during sloshing excitation. This study is performed by comparing the ANCF results with the results obtained using the smoothed particle hydrodynamics (SPH) approach, a mesh-free method widely used in the analysis of fluid dynamics problems. After verifying and validating the new ANCF liquid sloshing approach, nonlinear crude oil constitutive models are developed and integrated with detailed railroad vehicle models to study the effect of crude oil sloshing on railroad vehicle dynamics and stability. Finally, a new viscoelastic constitutive model and a new implicit numerical integration solution scheme are proposed to efficiently solve stiff systems of differential/algebraic equations (DAEs) by filtering and/or damping out ANCF high-frequency modes.