Modeling the Effect of Fluid-Structure Interaction on the Impact Dynamics of Pressurized Tank Cars

This paper presents a computational framework that analyzes the effect of fluid-structure interaction (FSI) on the impact dynamics of pressurized commodity tank cars using the nonlinear dynamic finite element code ABAQUS/Explicit. There exist three distinct phases for a tank car loaded with a liquefied substance: pressurized gas, pressurized liquid and the solid structure. When a tank car comes under dynamic impact with an external object, contact is often concentrated in a small zone with sizes comparable to that of the impacting object. While the majority of the tank car structure undergoes elastic-plastic deformations, materials in the impact zone can experience large plastic deformations and be stretched to a state of failure, resulting in the loss of structural integrity. Moreover, the structural deformation changes the volume that the fluids (gas and liquid) occupy and consequently the fluid pressure, which in turn affects the structural response including the potential initiation and evolution of fracture in the tank car structure. For an event in which the impact severity is low and the tank car maintains its structural integrity, shell elements following elastic-plastic constitutive relations can be employed for the entire tank car domain. For events in which the impact severity is higher and the tank car is expected to be punctured, an equivalent plastic strain based fracture initiation criterion expressed as a function of stress triaxiality is adopted for the material in the tank car’s impact zone. The fracture initiation is implemented for ductile, shear and mixed fracture modes and followed by further material deterioration governed by a strain softening law. Multi-layered solid elements are employed in the impact zone to capture this progressive fracture behavior. The liquid phase is modeled with a linear Us–Up Hugoniot form of the Mie-Gru¨neisen equation of state, and the gas phase is modeled with the ideal gas equation of state. Small to moderate amounts of fluid sloshing are assumed for an impacted tank car in this study. As such, the FSI problem can be solved with the Lagrangian formulation of ABAQUS, and appropriate contact algorithms are employed to model the multi-phase interactions. The force, displacement and impact energy results from the finite element analysis show good correlations with the available shell (side) impact test data. The puncture energy of a tank car in a shell impact scenario is further analyzed. It is demonstrated that the FSI effect needs to be adequately addressed in an analysis to avoid overestimating the puncture resistance of a tank car in an impact event.

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Explicit Finite Element Study of Liquid Sloshing Behavior in Fluid-Structure Interaction Condition

Volume 7: Fluids Engineering ◽

10.1115/imece2017-70832 ◽

2017 ◽

Author(s):

Shuo Yang ◽

Raymond K. Yee

Keyword(s):

Finite Element ◽

Water Level ◽

Similarity Theory ◽

Fluid Structure Interaction ◽

Water Levels ◽

Tank Wall ◽

Fluid Structure ◽

Structure Interaction ◽

Sloshing Phenomenon ◽

The Impact

As a common phenomenon in liquid motions, sloshing usually happens in a partially filled liquid tank of moving vehicle or structure. The objectives of this paper are to study sloshing behavior in rigid tank and deformable tank, and to develop a better performance baffle design in the tank under seismic excitations. The tank is surged with a sinusoidal oscillation about horizontal x-direction. The hydro-elasticity effect of sloshing pressure on the tank wall was taken into consideration due to the fluid-structure interaction between impact pressures and tank structures. ABAQUS finite element program using Coupled Eulerian-Lagrangian (CEL) technique was employed to simulate fluid sloshing. The sloshing phenomenon was studied in rigid tank and deformable tank models with three different water levels, and the effect of wall thickness of the deformable tank on sloshing behavior was discussed. One way to minimize the effect of sloshing in a tank, baffles are used and installed in the middle of the tank, and then various heights and material types of baffle were evaluated. The simulation results show that higher water level case creates greater pressure impact on the tank wall than lower water level case, and the elasticity of the tank structure would reduce the impact pressure of the wall. For the simulation tank model with size of 1m (H) × 1m (W) × 0.2m (D), better performance baffle was found to be the one with the height of 0.35m and was made of acrylic material. Moreover, the conclusion of this study can be extrapolated to other dimensions of the model based on similarity theory. This paper also can serve as an aid in further studying sloshing phenomenon. The findings of this study can be applied to restrain or minimize sloshing motions inside a tank.

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Finite Element Approximation of Fluid Structure Interaction (FSI) Optimization in Arbitrary Lagrangian-Eulerian Coordinates

Volume 7B: Fluids Engineering Systems and Technologies ◽

10.1115/imece2013-62291 ◽

2013 ◽

Cited By ~ 1

Author(s):

Bhuiyan Shameem Mahmood Ebna Hai ◽

Markus Bause

Keyword(s):

Finite Element ◽

Fluid Structure Interaction ◽

Arbitrary Lagrangian Eulerian ◽

Fluid Structure ◽

Structure Interaction ◽

Finite Element Software ◽

Special Cases ◽

Non Linear ◽

Non Linear System ◽

The Impact

Advanced composite materials such as Carbon Fiber Reinforced Plastics (CFRP) are being applied to many aircraft structures in order to improve performance and reduce weight. Most composites have strong, stiff fibers in a matrix which is weaker and less stiff. However, aircraft wings can break due to Fluid-Structure Interaction (FSI) oscillations or material fatigue. This paper focuses on the analysis of a non-linear fluid-structure interaction problem and its solution in the finite element software package DOpElib: the deal.II based optimization library. The principal aim of this research is to explore and understand the behaviour of the fluid-structure interaction during the impact of a deformable material (e.g. an aircraft wing) on air. Here we briefly describe the analysis of incompressible Navier-Stokes and Elastodynamic equations in the arbitrary Lagrangian-Eulerian (ALE) frameworks in order to numerically simulate the FSI effect on a double wedge airfoil. Since analytical solutions are only available in special cases, the equation needs to be solved by numerical methods. This coupled problem is defined in a monolithic framework and fractional-step-θ time stepping scheme are implemented. Spatial discretization is based on a Galerkin finite element scheme. The non-linear system is solved by a Newton method. The implementation using the software library package DOpElib and deal.II serves for the computation of different fluid-structure configurations.

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Verification of a Total Lagrangian ANCF Solution Procedure for Fluid–Structure Interaction Problems

Journal of Verification Validation and Uncertainty Quantification ◽

10.1115/1.4038904 ◽

2017 ◽

Vol 2 (4) ◽

Cited By ~ 5

Author(s):

Emanuele Grossi ◽

Ahmed A. Shabana

Keyword(s):

Finite Element ◽

Fluid Model ◽

Mass Matrix ◽

Fluid Structure Interaction ◽

Vertical Wall ◽

Three Dimensional ◽

Position Vector ◽

Fluid Structure ◽

Structure Interaction ◽

The Impact

The objective of this investigation is to verify a new total Lagrangian continuum-based fluid model that can be used to solve two- and three-dimensional fluid–structure interaction problems. Large rotations and deformations experienced by the fluid can be captured effectively using the finite element (FE) absolute nodal coordinate formulation (ANCF). ANCF elements can describe arbitrarily complex fluid shapes without imposing any restriction on the amount of rotation and deformation within the finite element, ensure continuity of the time-rate of position vector gradients at the nodal points, and lead to a constant mass matrix regardless of the magnitude of the fluid displacement. Fluid inertia forces are computed, considering the change in the fluid geometry as the result of the large displacements. In order to verify the ANCF solution, the dam-break benchmark problem is solved in the two- and three-dimensional cases. The motion of the fluid free surface is recorded before and after the impact on a vertical wall placed at the end of the dam dry deck. The results are in good agreement with those obtained by other numerical methods. The results obtained in this investigation show that the number of degrees-of-freedom (DOF) required for ANCF convergence is around one order of magnitude less than what is required by other existing methods. Limitations and advantages of the verified ANCF fluid model are discussed.

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Coupled Boundary and Finite Element Methods for the Solution of the Dynamic Fluid-Structure Interaction Problem

10.1007/978-3-642-51727-3 ◽

1992 ◽

Cited By ~ 38

Author(s):

Siamak Amini ◽

Paul John Harris ◽

David T. Wilton

Keyword(s):

Finite Element ◽

Finite Element Methods ◽

Fluid Structure Interaction ◽

Fluid Structure ◽

Structure Interaction ◽

Interaction Problem

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Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

Biogeosciences ◽

10.5194/bg-12-5871-2015 ◽

2015 ◽

Vol 12 (19) ◽

pp. 5871-5883 ◽

Cited By ~ 7

Author(s):

L. A. Melbourne ◽

J. Griffin ◽

D. N. Schmidt ◽

E. J. Rayfield

Keyword(s):

Climate Change ◽

Finite Element ◽

Structural Integrity ◽

Geometric Model ◽

Algal Growth ◽

Coralline Algae ◽

Rocky Shores ◽

Element Analysis ◽

Scan Data ◽

The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

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