Learning Forum

[shivamnehra]

i am doing a static structural analysis for break away moment. In solution information there is a possibility to see force convergence graph. What do the blue and magenta lines represent? If the represents external and internal loads, what are these internal and external loads?   

[jj77]

Very good question and good that you are looking on this graph.

The magenta (force conv.) is related to the FE unbalanced or residual forces (difference between external and internal forces) which need to be small enough of course for a solution to valid/converged thus they need to go below the light blue line called force criterion.

( The dashed green and blue vertical lines tell us when a sub step or a load step converged)

 

For more info on this see:

http://www.padtinc.com/blog/the-focus/solution-information-monitoring-your-solves-in-ansys-mechanical

 

http://www.padtinc.com/blog/the-focus/you-dont-wanna-step-to-this-breaking-down-loadsteps-and-substeps-in-ansys-mechanical

 

[shivamnehra]

Thanks for your kind reply. these links were helpful. thanks for that.

But what i can't get my head around are these internal and external forces everyone takes about.

Do the load applied by user count as External forces and thus generated inertial forces are called internal forces? Is this the case?

[JayanJoshua]

External forces include the active forces applied on the structure. For example the pressure force we apply over it and the self-weight of the structure.nInternal forces include the reactive force that is generated inside the structure that prevents the deformation of the structure and holds it stiff. These include the stress developed, the inertia forces, the product of stiffness the small displacements happening in the nodes.nOn the whole, the force which we apply externally must balance all the parameters that are developed internally when converted to equal units for calculation.nHope it helps n

[Johnny Blackwell]

Hello, as I know, in a static structural analysis for breakaway moment, the blue and magenta lines in the force convergence graph typically represent different components or aspects of the analysis. geometry dash lite

1. External Loads: External loads refer to the forces or loads applied to the structure from its surroundings or external sources. These loads can include applied forces, moments, pressure, temperature gradients, or any other external influences acting on the structure. For example, in a structural analysis of a bridge, external loads could include the weight of vehicles, wind forces, or thermal expansion.
2. Internal Loads: Internal loads are the forces and moments that develop within the structure as a result of external loads and the structural response. These internal loads are distributed throughout the structure and affect its internal components. Internal loads can include stresses, strains, displacements, bending moments, shear forces, or any other internal forces that arise due to the applied external loads.