crank statics problem 3d rigid body equilibrium

So the lesson above is that the applied forces must be correctly applied to get correct stress in an Inertia Relief model. Looking at the above three results, there continues to be no difference in stress as the supports move around for the same unbalanced force on the left edge only, except Weak Springs are slightly off. Compared with the results above where the forces were in static equilibrium, there is a huge difference in stress when the forces are not in static equilibrium because now there is a huge acceleration field applied to the solution. In the results below, there is only a force on the left edge. Looking at the above three results, Weak springs is slightly worse than the other two, but less than 0.5% difference from the ideal, which I would call an insignificant difference. For systems D, E, F, I only applied a force to the left edge, which requires there to be a ridiculously high acceleration to balance that force.

For systems A, B, C I applied equal and opposite forces on the left and right edges for the static equilibrium cases. I used three methods of supporting a structure to use with Inertia Relief: Weak Springs, Remote Displacement (Deformable) on the left, or a 3 point kinematic mount. Yes, you need supports on the static structural analysis when inertia relief is turned ON.

It was not related to what you replied, I was asking something different. However, I still wasn't able to get the answer for the question which I asked in my previous comment. Choosing the appropriate locations for the application of supports is still a topic which I am unsure of, like where and how many are needed. Even, as you have already said, if I want to look at the stresses and deformations, I need to solve the static structural model and without applying supports anywhere, I wouldn't be able to solve it. I would still need to apply supports somewhere, right? Maybe on a single point, maybe more than a point, maybe an edge, or maybe even a face? Otherwise, the static structural model will do a rigid body motion. Solve that static structural model with inertia relief to look at the stress and deformation in the conrod at that particular crank angle.'

This is an example of a model withno supports. You said, 'Only the mesh of the conrod is imported into static structural, not the crank or piston. ,I will consider the conrod example that you gave. If you are curious, use inertia relief on a fully supported structure and let us know what you find. If you have enough supports to avoid a singular matrix in static structural, why are you turning on inertia relief? Solve that static structural model with inertia relief to look at the stress and deformation in the conrod at that particular crank angle. This is an example of a model with no supports. Only the mesh of the conrod is imported into static structural, not the crank or piston. If you build a rigid dynamics model of those three parts, you can solve for the forces acting on each end of the conrod at every angle of the crank for any speed (rpm) of the crank.Ī classic use for inertia relief is to import from the rigid dynamics solution the force on each end of the conrod at a particular crank angle into static structural. An internal combustion engine has a piston that moves back and forth along the cylinder, a crank shaft that spins and a connecting rod (conrod) between them.

Crank statics problem 3d rigid body equilibrium