Time-Accurate Multibody Dynamics Model for Toroidal Traction Drives

2011 ◽  
Author(s):  
Cagkan Yildiz ◽  
Tamer M. Wasfy
Keyword(s):  
Multibody Dynamics ◽  
Transient Response ◽  
Search Algorithm ◽  
Hydrodynamic Lubrication ◽  
Rigid Bodies ◽  
Speed Ratio ◽  
Dynamics Model ◽  
Traction Drives ◽  
Toroidal Traction ◽  
Multibody Dynamics Model

A time-accurate multibody dynamics model for predicting the transient response of toroidal traction drives is presented. The model can be used to predict the system’s transient response due to variations in the input speed, variations in the output load, and changing the speed ratio. The model supports half and full-toroidal configurations, multiple transmitters and multiple cavities. The multibody system representing the toroidal drive is modeled using rigid bodies, revolute joints and rotational actuators. A penalty model is used to impose the joint/contact constraints. The contact model detects contact between discrete points on the surface of the transmitter and an analytical surface representation of the input and output shafts’ toroidal surfaces. A recursive bounding sphere contact search algorithm is used to allow fast contact detection. An elasto-hydrodynamic lubrication model is used for the tangential contact traction forces between the transmitter and the toroid. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. The model is partially validated by comparing to previously published steady-state models. The model can help improve the design of toroidal continuous-variable transmission systems including increasing the torque capacity and durability.

Multibody Dynamics Model of a Diesel Engine and Timing Gear Train With Experimental Validation

2016 ◽  
Author(s):  
Adam D. Foltz ◽  
Tamer M. Wasfy ◽  
Erik Ostergaard ◽  
Ilya Piraner
Keyword(s):  
Diesel Engine ◽  
Multibody Dynamics ◽  
Contact Surface ◽  
Search Algorithm ◽  
Gear Tooth ◽  
Gear Train ◽  
Dynamics Model ◽  
Normal Contact ◽  
Stiffness And Damping ◽  
Multibody Dynamics Model

High-powered Diesel engines typically use a timing gear train to couple/synchronize the camshaft rotation with the crankshaft and also to drive the accessories such as the fuel and oil pumps. In this paper a high-fidelity multibody dynamics model of a 6-cylinder inline Diesel engine and its timing gear train is presented. The multibody system representing the system is modeled using rigid bodies, torsional springs, revolute joints, prismatic joints, and rotational/linear actuators. A penalty model is used to impose joint and normal contact constraints. The normal contact penalty stiffness and damping techniques are used to model gear tooth stiffness and damping. The contact model detects contact between discrete points on the surface of a gear tooth (master contact surface) and a polygonal surface representation of the mating gear tooth (slave contact surface). A recursive bounding box/bounding sphere contact search algorithm is used to allow fast contact detection. Time-varying forces are applied to the cylinders to model the cylinder pressure variations due to combustion events as a function of the crank angle. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. The model is partially validated by comparing its predictions of the torsional vibrations of a Diesel engine’s crankshaft and moving parts to experimental measurements. Emphasis is given on the practicality of the modeling methods to industry.

Modeling and Simulation of Shoulder-Humerus Complex via Multibody Dynamics

2013 ◽  
Author(s):  
Nicholas D. Harrington ◽  
Shanzhong (Shawn) Duan
Keyword(s):  
Multibody Dynamics ◽  
Sports Medicine ◽  
Soft Tissues ◽  
Equations Of Motion ◽  
Computer Software ◽  
Rigid Bodies ◽  
Upper Body ◽  
Dynamics Model ◽  
Upper Arm ◽  
Multibody Dynamics Model

In this paper, a multibody dynamics model of the shoulder-upper arm complex is presented. Three major bones clavicle, scapula, and humerus in the shoulder-upper arm complex are represented by rigid bodies. The soft tissues such as tendons, ligaments, and muscles are modeled as springs and dampers respectively attached to the rigid bodies. The joints between the bones are expressed as ideal kinematic joints. Kane’s equations are then used to derive equations of motion of this multibody system. Based on the model, a person’s stand-up motion, aided by shoulder-upper arm complex force for lifting his/her upper body weight is analyzed. Commercial computer software is used to create the multibody shoulder-upper arm complex computational model and then carry out simulation. The model may be utilized in motion analysis of elderly people and sports medicine to study fatigue mechanism and prevent injuries of the shoulder-upper arm complex.

scholarly journals Multibody Dynamics Model and Simulation for the Totally Enclosed Lifeboat Lowered From Ship in Rough Seas

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 32171-32187
Author(s):  
Shaoyang Qiu ◽  
Hongxiang Ren ◽  
Haijiang Li ◽  
Yi Zhou ◽  
Delong Wang
Keyword(s):  
Multibody Dynamics ◽  
Dynamics Model ◽  
Model And Simulation ◽  
Multibody Dynamics Model

scholarly journals Multibody dynamics model of head and neck function in Allosaurus (Dinosauria, Theropoda)

10.26879/338 ◽  
2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Eric Snively ◽  
John R. Cotton ◽  
Ryan Ridgely ◽  
Lawrence M. Witmer
Keyword(s):  
Head And Neck ◽  
Multibody Dynamics ◽  
Dynamics Model ◽  
Neck Function ◽  
Multibody Dynamics Model

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.

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