Time Step in Explicit Dynamics - Lesson 2

Unlike implicit methods, explicit time integration methods are conditionally stable, meaning that they are stable only when the time step size is less than a certain limit. In this video, we learn how to calculate this upper limit or the critical time step. We then talk about the ways in which the mesh and the material properties influence the critical time-step. Finally, we discuss ways to manage the critical time step by either manipulating the mesh to ensure that no small elements drive the critical time step size down or by using mass scaling that selectively modifies the density to increase the critical time step size.

00:00 – Intro
00:49 – Conditional stability of explicit analysis
02:06 – Critical time step and CFL condition
02:55 – Characteristic length of an element
04:05 – Dependence of critical time step on material properties
05:46 – Increasing critical time step by modifying the characteristic length
07:15 – Mass scaling
08:05 – Checks associated with mass scaling
09:09 – Example demonstrating mass scaling
10:35 – Summary

// INTERESTED IN MORE?
Visit Ansys Innovation Courses for free courses that include videos, handouts, simulation examples with starting files, homework problems and quizzes.

Visit today → https://bit.ly/3Eo8esU

// DOWNLOAD FREE ANSYS SOFTWARE
Ansys offers free student product downloads for homework, capstone projects, student competitions, online learning and more!

Download today → https://bit.ly/32eEcuR

// QUESTIONS ABOUT THIS VIDEO OR USING ANSYS?
Get help from Ansys experts and peers through the Ansys Learning Forum. Search for answers to common questions, browse discussion categories or ask your own question.

Visit today → https://bit.ly/3qsytK2

// STAY IN THE LOOP
Follow our Ansys Academic LinkedIn showcase page for updates on learning resources, events, job opportunities, cutting-edge simulation content and more!

Follow today → https://bit.ly/3Bbaaow