Abstract
The variational form of the equations of dynamics is derived from its vector counterpart (Newton’s law) through the principle of virtual work, extended to dynamics thanks to d’Alembert principle. This leads to Hamilton’s principle and the Lagrange equations for discrete systems; a set of examples illustrate special features such as gyroscopic effects. The Lagrange equations are extended to systems with kinematic constraints and conservation laws are established in special conditions (Jacobi integral, conservation of generalized momentum). This chapter includes the treatment of the prestresses using the Green strain tensor to measure the deformation in prestressed flexible bodies. The geometric stiffness is discussed and its relation to buckling is established and illustrated by mechanisms aimed at introducing a negative stiffness (such mechanisms are used in vibration isolation of precision structures). The chapter ends with a set of problems.
Le bon sens est la chose la mieux
répartie au monde, parce que nul
ne se plaint de ne pas en avoir
assez.
Descartes, Discours de la
Méthode (1637)
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
This system is in fact a model of the Jeffcott rotor with an anisotropic shaft; it will be reexamined in Chap. 10.
- 2.
by analogy with the relation between the linear momentum, \(p=mv\), with the kinetic energy, \(T=\frac{1}{2}mv^2\), of a point mass: \(p=dT/dv\).
- 3.
This is sometimes called the “P-Delta” effect.
- 4.
The sum is intended on the repeated index \(m\).
- 5.
see [Geradin & Rixen, 1997, p.149–152]
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2013 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
Preumont, A. (2013). Lagrangian Dynamics. In: Twelve Lectures on Structural Dynamics. Solid Mechanics and Its Applications, vol 198. Springer, Dordrecht. https://doi.org/10.1007/978-94-007-6383-8_3
Download citation
DOI: https://doi.org/10.1007/978-94-007-6383-8_3
Published:
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-007-6382-1
Online ISBN: 978-94-007-6383-8
eBook Packages: EngineeringEngineering (R0)