'Double Crank Mechanism Analysis' simulation project by navaneeth


#1

I created a new simulation project called 'Double Crank Mechanism Analysis':

Double Crank Mechanism converts a reciprocating motion to a rotational motion and vice versa.Interesting for this mechanism is that it has three moments of standstill. This project aims at carrying structural analysis on the mechanism with two different loading configurations.


More of my public projects can be found here.


#2

The CAD model is courtesy of GrabCAD member Constatin. The model was modified by adding and removing features and parts for ease of meshing. The figure below shows the reduced model which was uploaded in the Simscale platform in STEP format. The model was in meters, therefore no scaling operation was performed.

The geometry was meshed using automatic tetrahedralisation at Coarse mesh setting.

There were two simulation runs performed with different loading configurations.

  1. Loading at Gear Teeth(1.5 MPa at two gear teeth) and restricting the displacement of one end of the T lever.
  2. Loading at one end of the T lever(200 N along -ve X axis) and restricting the displacement of Gear teeth.

Although, at first glance these two cases may seem similar, but by closer examination we may find that while the former corresponds to beginning of the return stroke(Gear driven), the later corresponds to end of the stroke(Piston Driven), resulting in lesser member movement. For understanding the difference you may also look at this video.Also, note that the loadings are arbitrary.

The shaft and end of the T Lever was allowed to rotate freely while displacement DOF was restricted using remote displacement condition. For the second case, a force of -100 N is applied at each hole in the T lever using remote force .Altogether there are seven contact boundary conditions(4 sliding contacts and 3 bonded contacts).

Result shows the displacement of each member after the load application for both the cases.

                 (Loading at Gear Teeth)

                         (Loading at the T lever end)

The result also shows the Von mises stress for the both the cases.

(Loading at Gear Teeth)


(Loading at T Lever)