Define the Beam Element Definition

Next, we assign the element type and element definition for the beam (part 5).

1. Right-click the Element Type heading for Part 5 in the browser (tree view) and select Beam. In a later step, we will add a prescribed rotation to the center of this joint. To transmit the rotational moment to the crank, we must change the element to a type that has rotational degrees of freedom (DOF), which make the element torsionally stiff. Trusses do not have rotational DOF and can only transmit axial loads.
2. Double-click the Element Definition heading for Part 5 in the browser.
   1. Select the first row of the Sectional Properties table and click Cross-Section Libraries.
      Tip: You can click the left end of a row or any column within a row to select the row.
      1. Select the Round option in the drop-down box at the upper-right corner.
      2. Type 0.5 in the Radius (R) field. The cross-section is arbitrary and is intended only to provide a relatively rigid joint.
      3. Click OK to accept the cross-sectional properties.
   2. Ensure that the Large Displacement option is selected in the Analysis Type drop-down list. If you change this option, a pop-up message appears. Click OK to dismiss the message.
   3. Click the Advanced tab.
      • Activate the Large rigid body rotation check box.  This option implements an alternative beam element formulation, which is necessary to ensure accurate stress results when the beams experience rigid body rotation.
   4. Click OK to accept the element definition.

Next