In Pro/ENGINEER Wildfire 2.0, it is now possible to transfer loads gathered in Mechanism Dynamics and pass them over to Mechanica Structure and run an analysis.  Here are the steps to accomplish this simple, but powerful process.

Capture the loads and transfer from Mechanism Dynamics.  For this example, we will focus on the chair lift mechanism of a rotating lever (see Figure 1).  The lever is forced upright by the two springs until it comes into contact with the cable by rotating on some pin joints.  We’ve simulated the way in which the lever comes into contact with the traveling cable through a cam connection.  You can see the start and end locations of the assembly in Figures 1 and 2.

After we run the dynamic analysis, we go to the top pull down menu and select MECHANISM>USE IN STRUCTURE.  The resulting dialog box is shown in Figure 3.

Now you have a few options to choose from: 

• Result Set—Select one of the analysis result sets you generated in the current session. You can use results from dynamic, static, or force balance analyses.
• Body—Select the body on your assembly that Mechanism Design uses to evaluate the loads during the selected analysis.
• Component—Select a part, subassembly, or assembly. Mechanism Design saves the load set as part of the component's file. You must select a component that is part of the body you selected for load evaluation.
• Evaluate At—Select one of the following options from the drop-down list to specify how the software will evaluate the loads you include in the transfer load set. Note that for force balance and static analyses, this area is inactive, and End is the default.
• Start or End—The software displays the beginning or ending time for the analysis, and the load list displays values for all loads at that time.
• Time—Enter a positive real-number value for the time in the entry box. The load list displays the load values for that time, and the model changes to the appropriate position for that analysis time.
• Single Load Max—The software determines the time during the analysis when a particular load is at its maximum, and evaluates all the loads at that time. When you select this option, another drop-down list appears containing all the available loads. Select the load of interest to display the analysis time when the load value is the greatest. The load list displays the maximum value for the selected load, and the value for all other loads at the same analysis time.
• Max for All Loads—The software displays the maximum value for each load in the list, regardless of when this occurs during the analysis.

Bring the load into Mechanica Structure.  We now enter into the lever part by itself and enter Mechanica Structure.  Here, you do the same things that you always do, by entering a material for the part and applying some constraints to hold it in place.  Next, you apply the loads from Mechanism Dynamics.  To do this, select INSERT>MECHANISM LOAD from the top pull down menu, resulting in the dialog box seen in Figure 4.

In this case, we need to apply all the loads, so keep all the boxes checked and click OK.  Your resulting model is shown in Figure 5.

Most loads become Total Load at a Point loading case and the points are created automatically.  Here we have three pin joints and one cam connection.  The joint reaction force is converted to an unassociated TLAP force at the joint point location.  The cam-follower connection combines the normal and tangential reaction forces at the cam contact point and converts this to an unassociated TLAP force at the cam contact point.  Now we must edit the loads (all four) and assign them to the correct surfaces or edges.  Figure 6 shows the definition of the TLAP load.

After all forces have been assigned to the appropriate geometry, you can now run the analysis in Mechanica.  Figure 7 shows the result of this analysis.

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Figure 2


Figure 3


Figure 4


Figure 5


Figure 6


Figure 7