• Home
  • About
  • Featured Articles
  • Editorial Team
  • Announcements
  • Home
  • About
  • Featured Articles
  • Editorial Team
  • Announcements
JOURNAL OF COMPUTATIONAL AND NONLINEAR DYNAMICS
  • Home
  • About
  • Featured Articles
  • Editorial Team
  • Announcements

Featured Articles

    Archives

    March 2023
    February 2023
    September 2022
    August 2022
    April 2022
    March 2022
    December 2021
    October 2021
    September 2021

    Categories

    All
    Actuators
    Approximation
    Artificial Neural Networks
    Bifurcation
    Boundary Conditions
    Boundary-value Problems
    Contact
    Continuation Methods
    Control
    Co-simulation
    Co-simulation Interface
    Damping
    Density
    Dynamic Models
    Dynamics
    Dynamic Systems
    Error Estimator
    Errors
    Exact Mode Shapes
    Exoskeleton Devices
    Friction
    Fuzzy Logic
    Geometry
    Heat
    Kinematics
    Limit Cycles
    Loaded Beam
    Manifolds
    Manipulators
    Midplane Stretching
    Multibody Dynamics
    Multibody Systems
    Multiphysics
    Multirate
    Noise
    Nonlinear Dynamical Systems
    Nonlinear Frequency
    Nonlinear Vibration
    Nonlinear Vibration Absorber
    NVA
    Origami
    Parallelization
    Parametrization
    Perturbation Methods
    Probability
    Prostheses
    Railroad Dynamics
    Real-time Dynamics Simulation
    Resonance
    Ships
    Simulation
    Solver Coupling
    Space
    Stability
    Time Delay Systems
    Topology
    Variable Macro-step Size
    Vehicular Dynamics
    Vibration
    Waves

    RSS Feed

Back to Blog

Co-Simulation Multibody Systems With Contac Using Reduced Interface Models

10/4/2021

 
Albert Peiret, Francisco González, József Kövecses​, and Marek Teichmann (February 24, 2020). "Co-Simulation of Multibody Systems With Contact Using Reduced Interface Models." ASME. J. Comput. Nonlinear Dynam. April 2020; 15(4): 041001. https://doi.org/10.1115/1.4046052
Picture
Co-simulation techniques enable the coupling of models of physically diverse subsystems in an efficient and modular way. Communication between subsystems takes place at discrete time points and is limited to a given set of coupling variables, while the internal details of the subsystems remain undisclosed, and are generally not accessible to the rest of the simulation environment. This can lead to the instability in non-iterative co-simulation that is commonly used  in real-time applications. The stability of the simulation in these cases can be enhanced using reduced, effective models of one or more subsystems. These reduced models provide physically  meaningful information to the other subsystems between communication points.  This work describes such interface models and their application in co-simulation for nonsmooth mechanical systems subjected to unilateral contact and friction. The performance of the proposed approach is shown in some challenging examples of non-iterative, multirate co-simulation interfacing mechanical and hydraulic subsystems. The use of an interface model improves stability and allows for larger integration step-sizes, thus resulting in more efficient simulation. 
0 Comments
Read More
Back to Blog

Exact Nonlinear Dynamic Analysis of a Beam With a Nonlinear Vibration Absorber and With Various Boundary Conditions

9/27/2021

 
Mohammad Bukhari and Oumar Barry (November 11, 2019). "Exact Nonlinear Dynamic Analysis of a Beam With a Nonlinear Vibration Absorber and With Various Boundary Conditions." ASME. J. Comput. Nonlinear Dynam. January 2020; 15(1): 011003. https://doi.org/10.1115/1.4045287
Picture

Beams are the basic component of many engineering applications. They are used in bridges, overhead transmission lines, pipelines, sensors, aircraft structures, and many others. To ensure safety and proper function, vibrations of beams need to be investigated for better prediction of the system dynamical response. When the vibration amplitude is small, linear theory can predict the response accurately. However, when the vibration amplitude becomes larger, nonlinearity must be considered to avoid erroneous results. This work investigates the nonlinear vibration of a beam with attached Nonlinear Vibration Absorber (NVA) consisting of a spring-mass system). The considered nonlinearity stems from mid-plane stretching due to immovable boundary conditions and from the nonlinear stiffness in the NVA. In addition, different types of immovable boundary are investigated. For weak nonlinearity, an approximate analytical solution is derived using the method of multiple scales. These analytical results are validated using direct numerical integration. Parametric studies demonstrate that the performance of the NVA does not only depend on its key design variables and location, but also on the beam boundary conditions, midplane stretching of the beam, and NVA configuration (i.e., grounded versus ungrounded). Our analysis also indicates that the common approach of employing approximate modes in estimating the nonlinear response of a loaded beam produces significant error, up to 1200% in some cases. These findings could contribute to the design improvement of NVAs, microelectromechanical systems (MEMS), energy harvesters, and metastructures. 

​
0 Comments
Read More
Back to Blog

Vehicle Shimmy Modeling With Pacejka’s Magic Formula and the Delayed Tire Model

9/8/2021

 
Tian Mi, Gabor Stepan, Denes Takacs, and Nan Chen (January 23, 2020). "Vehicle Shimmy Modeling With Pacejka's Magic Formula and the Delayed Tire Model." ASME. J. Comput. Nonlinear Dynam. March 2020; 15(3): 031005. https://doi.org/10.1115/1.4045943
Picture

Shimmy is a self-excited vibration which can appear in various wheeled mechanisms such as trailers, motorcycles, bicycles, cars, landing gears of aircrafts, and even baby strollers or supermarket trolleys. Shimmy of cars is also known as vehicle shimmy or death wobble. The cause of shimmy is related to the dynamic characteristics of the tire-road contact and the overall system structure. It increases tire wear, deteriorates vehicle handling, and causes further instability problems of the whole vehicle.

In this paper, a 3 degree-of-freedom model of vehicle front wheels with dependent suspension is studied from the viewpoint of possible appearance of shimmy, and two tire models are compared. The two tire models have essentially different assumptions: Pacejka’s magic formula uses linearization in space along the tire-ground contact line where the tire points stick to the ground, while the delayed tire model uses linearization in time by considering small (but spatially nonlinear) lateral deformations of the tire in the contact region. The theoretical results show that the delayed tire model presents additional instabilities (i.e., shimmy) at low speeds, and especially at low damping values.

The investigation of this model is motivated by the occurrence of shimmy on some heavy vehicles and jeeps with worn front wheel suspension system, and the conclusions might be useful in the future study of shimmy in systems with independent suspensions of some electric vehicles.
0 Comments
Read More
Picture
JOURNAL OF COMPUTATIONAL and
​NONLINEAR DYNAMICS
COMPANION

QUICK LINKS

Submit Paper
Author Resources
Digital Collection
Indexing Information
Order Journal
Announcements and Call for Papers
Copyright © 2021 Journal of Computational and Nonlinear Dynamics