Coupled Multibody Dynamics and Smoothed Particle Hydrodynamics for Predicting Liquid Sloshing for Tanker Trucks

2014 ◽  
Author(s):  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Dynamic Response ◽  
Multibody Dynamics ◽  
Smoothed Particle Hydrodynamics ◽  
Search Algorithm ◽  
Contact Detection ◽  
Contact Search ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Contact Surfaces ◽  
Fluid Particles

Multibody dynamics and smoothed particle hydrodynamics (SPH) are integrated into one solver for predicting the dynamic response of tanker trucks. Multibody dynamics techniques are used to model the various vehicle components and connect those components using various types of joints and contact surfaces. A penalty technique is used to impose joint and normal contact constraints (between the tires and ground, and between the tank and the fluid particles). An asperity-based friction model is used to model joint and contact friction. The liquid in the tanks is modeled using an SPH particle-based approach. A contact search algorithm that uses a moving Cartesian Eulerian grid that is fixed to the tank is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between polygonal contact surfaces and the fluid particles. The governing equations of motion for the solid bodies and the fluid particles are solved along with joint/constraint equations using a time-accurate explicit solution procedure. The integrated solver is used to predict the dynamic response of a typical tanker truck performing a braking test with an empty, half-full and full tank. The solver can be used in vehicle design optimization to simulate and evaluate various vehicle designs.

Coupled Multibody Dynamics and Smoothed Particle Hydrodynamics for Modeling Vehicle Water Fording

2015 ◽  
Author(s):  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Multibody Dynamics ◽  
Smoothed Particle Hydrodynamics ◽  
Search Algorithm ◽  
Vehicle Body ◽  
Contact Detection ◽  
Water Pool ◽  
Contact Search ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Fluid Particles

Multibody dynamics and smoothed particle hydrodynamics (SPH) are integrated into one solver for predicting the water fording dynamic response of ground vehicles. Multibody dynamics models are used for the various vehicle systems including: suspension system, wheels, steering system, axles, differential, and engine. A penalty technique is used to impose joint and normal contact constraints (between the tires and ground, and between the tires/vehicle body and the fluid particles). An asperity-based friction model is used to model joint and contact friction. Water is modeled using an SPH particle-based approach along with a large eddy-viscosity turbulence model. A contact search algorithm that uses a Cartesian Eulerian grid around the water pool is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between polygonal contact surfaces (representing the tires and vehicle body) and the fluid particles. The governing equations of motion for the solid bodies and the fluid particles are solved along with joint/constraint equations using a time-accurate explicit solution procedure. The integrated solver is used to predict the dynamic response of a Humvee-type vehicle moving through a shallow water pool.

Coupled Multibody Dynamics and Discrete Element Modeling of Vehicle Mobility on Cohesive Granular Terrains

2014 ◽  
Author(s):  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Multibody Dynamics ◽  
Search Algorithm ◽  
Soft Soil ◽  
Discrete Element ◽  
Friction Model ◽  
Contact Friction ◽  
Contact Detection ◽  
Normal Contact ◽  
Contact Search ◽  
Contact Surfaces

Multibody dynamics and the discrete element method (DEM) are integrated into one solver for predicting the dynamic response of ground vehicles which run on wheels and/or tracks on cohesive soft soils (such as mud and snow). Multibody dynamics techniques are used to model the various vehicle components and connect those components using various types of joints and contact surfaces. A penalty technique is used to impose joint and normal contact constraints. An asperity-based friction model is used to model joint and contact friction. A soft cohesive soil material model (that includes normal and tangential inter-particle force models) is presented that can account for soil compressibility, plasticity, fracture, friction, viscosity, cohesive strength and flow. A Cartesian Eulerian grid contact search algorithm is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between the particles and polygonal contact surfaces. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. Numerical simulations of a typical vehicle going over a slopped soft soil terrain are presented to demonstrate the integrated solver. The solver can be used in vehicle design optimization.

Coupled Multibody Dynamics and Discrete Element Modeling of Bulldozers Cohesive Soil Moving Operation

2015 ◽  
Author(s):  
Akshay Sane ◽  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Multibody Dynamics ◽  
Search Algorithm ◽  
Cohesive Soil ◽  
Discrete Element ◽  
Cohesive Strength ◽  
Contact Friction ◽  
Contact Detection ◽  
Normal Contact ◽  
Contact Search ◽  
Contact Surfaces

Multibody dynamics and the discrete element method are integrated into one solver for modeling the excavation and moving operation of cohesive soft soil (such as mud and snow) by bulldozers. A soft cohesive soil material model (that includes normal and tangential inter-particle force models) is presented that can account for soil flow, compressibility, plasticity, fracture, friction, viscosity, gain in cohesive strength due to compression, and loss in cohesive strength due to tension. Multibody dynamics techniques are used to model the various bulldozer components and connect those components using various types of joints and contact surfaces. A penalty technique is used to impose joint and normal contact constraints. An asperity-based friction model is used to model joint and contact friction. A Cartesian Eulerian grid contact search algorithm is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between the particles and polygonal contact surfaces. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. A numerical simulation of a bulldozer performing a shallow digging operation in a cohesive mud-type soil is presented to demonstrate the integrated solver. The solver can be used to improve the design of the various bulldozer components such as the blade geometry, tire design, and track design.

High-Fidelity Modeling of a Backhoe Digging Operation Using an Explicit Multibody Dynamics Code With Integrated Discrete Particle Modeling Capability

2013 ◽  
Author(s):  
Shahriar G. Ahmadi ◽  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Multibody Dynamics ◽  
Search Algorithm ◽  
Equations Of Motion ◽  
Friction Model ◽  
Rigid Bodies ◽  
Contact Friction ◽  
Contact Detection ◽  
High Fidelity ◽  
Normal Contact ◽  
Contact Search

A high-fidelity multibody dynamics model for simulating a backhoe digging operation is presented. The backhoe components including: frame, manipulator, track, wheels and sprockets are modeled as rigid bodies. The soil is modeled using cubic shaped particles for simulating sand with appropriate inter-particle normal and frictional forces. A penalty technique is used to impose both joint and normal contact constraints (including track-wheels, track-terrain, bucket-particles and particles-particles contact). An asperity-based friction model is used to model joint and contact friction. A Cartesian Eulerian grid contact search algorithm is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between polygonal contact surfaces. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. The model can help improve the performance of construction equipment by predicting the actuator and joint forces and the vehicle stability during digging for various vehicle design alternatives.

scholarly journals An Efficient Sleepy Algorithm for Particle-Based Fluids

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xiao Nie ◽  
Leiting Chen ◽  
Tao Xiang
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Flow Behavior ◽  
Visual Quality ◽  
Repulsive Force ◽  
Performance Gain ◽  
Weakly Compressible ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Fluid Particles ◽  
Computational Resources

We present a novel Smoothed Particle Hydrodynamics (SPH) based algorithm for efficiently simulating compressible and weakly compressible particle fluids. Prior particle-based methods simulate all fluid particles; however, in many cases some particles appearing to be at rest can be safely ignored without notably affecting the fluid flow behavior. To identify these particles, a novel sleepy strategy is introduced. By utilizing this strategy, only a portion of the fluid particles requires computational resources; thus an obvious performance gain can be achieved. In addition, in order to resolve unphysical clumping issue due to tensile instability in SPH based methods, a new artificial repulsive force is provided. We demonstrate that our approach can be easily integrated with existing SPH based methods to improve the efficiency without sacrificing visual quality.

Parallel Transient Dynamics Simulations: Algorithms for Contact Detection and Smoothed Particle Hydrodynamics

1998 ◽  
Vol 50 (1-2) ◽  
pp. 104-122 ◽  
Author(s):  
Steve Plimpton ◽  
Steve Attaway ◽  
Bruce Hendrickson ◽  
Jeff Swegle ◽  
Courtenay Vaughan ◽  
...  
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Transient Dynamics ◽  
Contact Detection ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Dynamics Simulations
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