MechBytes Talk this Tuesday: Theresa Honein

[Ian Vincent Li]

Dear all,

This week's talk will be on Tuesday, October 29th, from 11:10 am to 12:00 pm in 3110 Etcheverry Hall and https://berkeley.zoom.us/j/95785043475.

The speaker is Theresa , who was advised by Prof. Oliver O’Reily from the mechanical engineering department, and she will be speaking about “On the Dynamics of Constraint Rigid Bodies”

Here is the abstract: 

Constraints play a key role in dictating the configurations and dynamics of mechanical systems. In this talk, we consider the effect of constraints on three mechanical systems: a rolling sphere, the transport of two cylindrical gas tanks, and a stack of blocks.

Firstly, we study the holonomy of a rolling sphere that traverses a closed rectangular path. We formulate a numerical method to obtain any desired orientation of the sphere by rolling the sphere such that its center of mass traces a single rectangular path. We also present an illuminating analogy between the Euler angles representation of the rotations of a sphere and a rolling sphere tracing three rectangles in the plane.

Next, we study a popular (yet unsafe) method of transporting cylindrical gas tanks. The method involves rolling both tanks at opposite angles of inclination to the vertical while maintaining point contact between the tanks. By propelling one of the tanks, both tanks can be transported together, with their centers of mass moving in straight lines. We simulate this motion and show that this transportation method is mechanically advantageous. We also discuss the optimum transportation of one and two cylinders and analyze the possible system of constraints on the pair of contacting cylinders.

Our third and final system is the classic problem of a stack of blocks. We develop a model for the dynamics of the blocks: one that incorporates Coulomb friction between the blocks, possible changes in contact configurations, and dynamic effects. We observe an abundance of solutions in some motions of the stack. We also study the stability of the stack subject to several static and dynamic experiments and distinguish our results from the classic results associated with the Painleve paradoxes.

Theresa Honein earned her Ph.D. in Mechanical Engineering at the University of California, Berkeley in Summer 2024 under Professor Oliver O’Reilly. She is interested in utilizing tools from dynamics and mechanics to create physically accurate simulations of seemingly simple, yet actually difficult to model, phenomena. She has previously studied the treatment of holonomic and nonholonomic constraints in different formulations of the equations of motion. She is currently interested in leveraging recent advances in numerical methods to model the nonsmooth dynamics of impacting rigid bodies.

If you are interested in learning more about Theresa's work, you can find her webpage (https://thh00.github.io/) .

Coffee and donuts will be provided in-person!

Best,

Ian