Possible to specify SurfaceTraction in one direction only?

Hi,

I am modeling a 2D plane strain elastic problem. When specifying the boundary conditions, is it possible to specify the tangential force on a boundary without specifying the normal force?

For example, if I want to specify a tangential force Fy, but I don't want to specify the normal force Fx, I would like to do something like

structuralBoundaryLoad(model,'Edge',1,'SurfaceTraction',[~;Fy]);

From the documentation, I can't see a way of doing this without also specifying Fx. Is this possible?

Thanks

[Ayush]

Is passing Fx = 0 causing errors?

Answer 1

[Dheeraj]

Hi,

I understand that you are trying to specify a tangential force without explicitly specifying the normal force in the provided function call. In a 2D plane strain elastic problem, the stress state is typically represented by a 3x3 stress tensor, which includes components for normal stresses and shear stresses.

In the context of specifying boundary conditions, the function you provided appears to use the surface traction vector as an input. However, the tangential force (Fy) and normal force (Fx) components are usually part of this vector, and it may not be possible to decouple them using a direct function call, at least in the typical sense.

If you want to apply a tangential force without specifying the normal force explicitly, you may need to decompose the surface traction vector into its normal and tangential components manually based on your knowledge of the problem. In your case, you may set (σxx) and (σyy) to zero and only provide the tangential component corresponding to the tangential force.

% Set up your model and geometry
% Specify tangential force Fy
Fy = 100; % Replace with your desired value
% Set normal and tangential components of surface traction vector
surfaceTraction = [0; 0; Fy];
% Apply boundary load with the specified surface traction
structuralBoundaryLoad(model, 'Edge', 1, 'SurfaceTraction', surfaceTraction);

Hope this helps!