Euler-Bernoulli Beam

With this posting I would like to ask the developers of FEATool why the transient analysis of Euler-Bernoulli beam bending equation problem is not correctly solved. It does not work as an hyperbolic problem with a second-order time derivative, instead it works as a parabolic (damped) problem with first-order derivative.  Even though the equation script shows a second-order operator in time, the response is as if a first-order in time equation is solved, as in the case of transient heat transfer equation.  This is true for 2D or 3D transient elasticity equations too.  

Also, why are the boundary conditions either fixed (clamped) at one end, free or point load in the other end.  In other words, why a simply supported beam can't be solved?

Thank you for trying the toolbox and getting in touch again.

The answer is simply that we haven't had time/resources to implement it yet. Especially laterly when the Mathworks recently changed the Matlab GUI framework without prior notice (which wasn't working at all for the toolbox), we had to focus on implementing a new GUI to support users using Matlab 2025a and later.

In the case of structural mechanics (and other similar physics) we haven't implemented a (time-dependent) solver for hyperbolic systems. And similarly for the boundary conditions (you can however set arbitrary boundary conditions by modifying the equations/bcs directly in m-script models).

The rest of the year we are focusing on making Matlab (MCR) optional, as also adding full support for Python scripting as an option. But hopefully we can get around to implementing these features afterwards.

Thank you for bringing it up though, it is good to get a feeling for what features and functionality users are missing.

Thank you for your response.  Can you please direct me to an example how I can incorporate different boundary conditions in this beam bending case with m-script models.  

Hi, to specify boundary constraints (not available in the FEATool Multiphysics GUI) you need to directly manipulate the "fea.bdr.d" (Dirchlet) and "fea.bdr.n" (Neumann) data fields. These fields either prescribe Dirichlet conditions, or Neumann (if a Dirchlet boundary is not set, i.e. empty []). The shape and formulation of the "bdr.d/n" fields are described a little further in the documentation, linked here https://featool.com/doc/feastruct#bdr_struct

The fields look a little different in your case since the Euler-Beam example uses Hermite shape functions, that is one row for the displacement "v", and a second for the gradient "vx", also as described https://www.featool.com/tutorial/2017/05/30/Euler-Bernoulli-Beam-Matlab-Simulation-in-FEATool-Multiphysics/

To illustrate I have attached a m-script file for the case of a beam with a center point load and simple supported edges: ex_euler_beam4.m