Looking for a book on non-holonomic constraints with worked examples

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Discussion Overview

The discussion revolves around the search for resources on non-holonomic constraints, particularly focusing on worked examples that can aid in understanding the theoretical aspects of the topic. Participants express a desire for materials that bridge the gap between theory and practical application, specifically within the context of Lagrangian mechanics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant notes that existing online resources on non-holonomic constraints are overly theoretical and lack practical examples, suggesting that worked examples would help in understanding the theory.
  • Several participants recommend specific books, including works by Whittaker, Marsden, and Bloch, as potential resources for understanding non-holonomic constraints.
  • There is a discussion about the relationship between curvature and holonomic versus non-holonomic constraints, with one participant expressing a belief that rolling without slipping on surfaces of varying curvature can be classified accordingly.
  • Another participant challenges the definitions of "virtual displacements" and "virtual work" as presented in Goldstein's work, suggesting that they are too narrow and must adhere to certain conditions.
  • Some participants raise questions about the nature of mechanical systems with nonlinear velocity constraints, expressing uncertainty about the mathematical treatment and existence of such systems.
  • One participant shares a past exam question involving holonomic and non-holonomic constraints, discussing the need to express certain constraints in specific forms for analysis.
  • There is a contention regarding the classification of constraints in a problem sheet, with participants debating whether certain constraints are indeed non-holonomic.
  • Another participant describes a scenario involving a rolling cylinder and discusses the degrees of freedom and generalized coordinates, asserting that the system can be holonomic under certain conditions.

Areas of Agreement / Disagreement

Participants express a variety of views on the classification of constraints, the adequacy of existing resources, and the definitions of key concepts. No consensus is reached on the nature of nonlinear velocity constraints or the correctness of certain theoretical interpretations.

Contextual Notes

Some discussions highlight limitations in existing literature and the need for clearer examples, particularly regarding the application of theoretical concepts to practical problems. There are unresolved questions about the mathematical treatment of nonlinear constraints and the implications of various definitions.

PhDeezNutz
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A lot of the notes online about non-holonomic constraints are mathematically/theoretically heavy with no real worked examples. I feel like worked examples are a good place to start; it gives me an (incomplete) overview that helps me see the “forest from the trees”. If I can see the “forest from the trees” then that would help to motivate the theory. As it is right now all the notes online seem like “formula soup” to me. I’m looking for something that is digestible.To be clear I’m looking for the Lagrangian- treatment of general non-holonomic constraints.

##f_j \left(q_1,...,q_n, \dot{q}_1,..., \dot{q}_n\right) = c_j##

Depending on the problem at hand you can change the constraints to pure position constraints or pure velocity constraints but I’m trying to learn how to handle a most general situation.

thanks in advance for pointing me
 
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Whittaker has a chapter. See attached.
 

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caz said:
Whittaker has a chapter. See attached.

Thank you for posting. It’s funny that they should mention curvature of a surface. I always thought that

rolling without slipping on a surface with constant curvature = holonomic

and

rolling without slipping on a surface with non-constant curvature = non-holonomic

So at first glance it seems like Whitaker corroborates my notions.

I’ll check it out. Thank you again.
 
caz said:

Marsden is my kind of guy (R.I.P.). We used his vector calculus book in my multivariable calc class and I thoroughly enjoyed it. From perusing papers on non-holonomic dynamics it seems like Bloch is an important player so I’m glad to see they wrote a book together.

On a related note I’m finding that the notion of “virtual displacements” and “virtual work” as defined in Goldstein is sort of wrong or at least very narrow in scope.

https://arxiv.org/pdf/physics/0510204.pdf

Virtual displacements aren’t completely arbitrary as one would be led to believe from reading Goldstein. In fact they must be perpendicular to the forces of constraint even if the actual displacements are not.

that’s my take from reading the above paper.
 
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The trick is then of course to introduce the Lagrange multipliers! Goldstein is nevertheless wrong in his use of the action principle with non-holonomous constraints (he's right about it using d'Alembert's principle).
 
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By the way nobody knows mechanical systems with constraints that are nonlinear in velocities besides a pair of pretty artificial constructions
 
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wrobel said:
By the way nobody knows mechanical systems with constraints that are nonlinear in velocities besides a pair of pretty artificial constructions
What's the nature of problem with such systems (those with constraints non-linear in velocity)? Is the mathematical machinery not up to the task? Are the results nonsensical?
 
  • #10
Haborix said:
What's the nature of problem with such systems (those with constraints non-linear in velocity)?
Problem is to bring an example of such a system
 
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  • #11
Ah, I see, thanks.
 
  • #12
wrobel said:
Problem is to bring an example of such a system

One of my grad classical mechanics test questions (in 2017) was the following

Image 3-2-21 at 11.45 AM.jpg


The constraints I come up with are

##f \left(x,y\right) = y - A\cos \left( k x \right) = 0####g\left( \dot{x} , \dot{y} , \dot{\theta} \right) = \sqrt{\dot{x}^2 + \dot{y}^2} - R \dot{\theta} = 0##

The first being holonomic and the second being non-holonomic. I believe the second constraint must be put into the form of ##g\left( \dot{x} , \dot{y} , \dot{\theta} \right) ## in order to answer part e)

For what it's worth I know that my professor did not use this question in later semesters.
 
  • #13
PhDeezNutz said:
The first being holonomic and the second being non-holonomic.
If you mean that the problems sheet you brought contains nonholonomic problems that is wrong.
 
  • #14
wrobel said:
If you mean that the problems sheet you brought contains nonholonomic problems that is wrong.
Isn’t rolling without slipping on a surface of non-constant curvature a non-holonomic constraint?

I believe in order to solve for the force of constraint in part e) you need to cast the second constraint as a non-holonomic constraint (i.e. a purely velocity constraint?)

##g\left( \dot{x} , \dot{y} , \dot{\theta} \right) = \sqrt{\dot{x}^2 + \dot{y}^2} - R \dot{\theta} = 0##The constraint may be linear in overall velocity

##v = \sqrt{\dot{x}^2 + \dot{y}^2}##

But it's not linear in ##\dot{x}## or ##\dot{y}## (Which again I think we have to keep ##\dot{x}## and ##\dot{y}## separate in order to solve for the force of constraint).

Unless there is a way to "linearize" this constraint that I don't know of.
 
  • #15
If a cylinder rolls on the floor of the form y=f(x) then the center of the cylinder describes a curve y=g(x). This is under assumption that the radius of the cylinder is smaller than 1/curvature of the floor. The function g is determined by f.

If the cylinder can slip then this is a system with two degrees of freedom. Generalized coordinates are the angle of cylinder's rotation and x-coordinate of the center of the cylinder. These two coordinates as well as corresponding generalized velocities are independent. The system is holonomic.
 
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