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Introduction
Published in Parviz E. Nikravesh, Planar Multibody Dynamics, 2018
Analytical methods for formulating the equations of motion and numerical methods for solving them are the basis for developing computer programs to determine the response of a multibody system. This requires systematic techniques for formulating and generating the kinematic and dynamic equations of motion, numerical methods for solving them, and preferably a front-end graphical interface for communicating the input and the output to the user. Such a computer program can be developed either as a special-purpose or as a general-purpose program.
Using real-time simulation in company value chains and business models for value creation
Published in Juhani Ukko, Minna Saunila, Janne Heikkinen, R. Scott Semken, Aki Mikkola, Real-time Simulation for Sustainable Production, 2021
Maya Kristina Cheikh-el-Chabab, Olli Kuivalainen, Ulf R. Andersson, Roope Eskola, Aki Mikkola
For example, hydraulic actuators output the required forces to the mechanical system, which responds by moving within its motion constraints. Multibody system dynamics is the basis of the mechanical subsystem modeling, and it includes the description, e.g., of the bodies, joints, contacts, and tires. In a multibody approach, the set of position coordinates can be defined using generalized global or relative coordinates (Jalon and Eduardo, 2012). A selected set of coordinates is also used to define the velocities and accelerations of the system bodies.
Nature Inspired Optimization for Controller Design
Published in Jitendra R. Raol, Ramakalyan Ayyagari, Control Systems, 2020
Jitendra R. Raol, Ramakalyan Ayyagari
The multibody system is applied to a broad variety of engineering problems from aerospace to civil engineering, from vehicle design to micromechanical analysis, and from robotics to biomechanics. The requirements for more complex models and the fast development of more and more powerful computers led to the development of multibody system dynamics.
Multibody system design based on reference dynamic characteristics: gyroscopic system paradigm
Published in Mechanics Based Design of Structures and Machines, 2023
Ayman A. Nada, Abdullatif H. Bishiri
The multibody system is a model that represent a physical system of interconnected bodies, each of which may undergo large translational and rotational displacements (Serban and Haug 1998; Shabana 2009, 2013). The relative motion between these bodies can be described by using geometric constraints that express the type of motion (Korkealaakso et al. 2009). The dynamic modeling and simulation of multibody systems have been recognized as a key aid in the analysis, design, optimization, and control of mechanical systems (Kim and Yoo 2013),. In multibody systems approach, the configuration of a rigid body can be fully defined by locating a Cartesian set of coordinate attached to the rigid body (called body-frame) relative to some inertial coordinate axes. Three parameters are needed to define the origin of body-frame and other parameters set are needed to specify the orientation of body-frame with respect to the inertial frame (Shabana 2009, 2013; Nada et al. 2009). A vector can describe the rigid translation of each body, and the respective velocity and accelerations are direct first and second-order time derivatives of the translation vector. However, the description of the rotation in three-dimensional space is more complex, as rotations about different axes are not independent. Several sets of parameters have been developed to describe the rotational kinematics in 3 D space. Among these types are Rodriguez parameters, Euler angles, direction cosines and Euler parameters. Euler angles are one of the most common and widely used parameters in modeling multibody system dynamics (Ozgoren 2019).
A survey on the modelling of air springs – secondary suspension in railway vehicles
Published in Vehicle System Dynamics, 2022
I. Mendia-Garcia, N. Gil-Negrete Laborda, A. Pradera-Mallabiabarrena, M. Berg
Regarding mechanic and thermodynamic modelling techniques, they are accepted by railway multibody developers for the virtual representation of the air springs in multibody rail vehicle simulations until 20 Hz [128]. A multibody system is a mechanical model consisting of separate bodies that are characterised by their mass and inertia properties, which are interconnected by joints, kinematic constraints and force/torque elements. That is why, generally, multibody softwares (e.g. Vampire, Simpack, Gensys, Adams, Sidive) use traditional mechanical lumped parameter models. Even if lumped parameter models are constantly used, their basics were established more than a decade ago and only few changes have been included during the last years. These models are consolidated on the study of vertical behaviour in which few parameters influence air spring behaviour (vertical loads). However, lateral stiffness is affected by more factors (bellow material and structure, preload, vertical load, shear forces and moments), parameters which cannot easily represent the physical reality, being the major problem the knowledge of the model parameters with enough precision. Thus, different researches are concerned with identifying vehicle model parameters (including the secondary suspension) using stationary tests [128] defined in the acceptance process of railway vehicles with the aim of reducing uncertainties [54,61,79,133]. Moreover, A. Facchinetti et al. investigate the impact of the pneumatic secondary suspension modelling on the results of multibody simulations from the virtual certification perspective [57].
Forward and inverse dynamics modeling of human shoulder-arm musculoskeletal system with scapulothoracic constraint
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Tingli Hu, Johannes Kühn, Sami Haddadin
The human musculoskeletal system can be described as a multibody system actuated by musculotendinous actuators. The dynamics of a multibody system can be described mathematically by its equations of motion, which can be derived using Newton-Euler or Lagrangian formulation (Simeon 2013). With the equations of motion, one is able to solveforward dynamics, i.e., predicting the movement trajectory1 while the multibody system is being actuated by a given generalized force, andinverse dynamics, i.e., estimating the generalized force which is required for the multibody system to perform a given movement trajectory.