Define the Beam Element Definition

Next, we will assign the element definition for the beam (Part 6).

Right-click the Element Type heading for Part 6 in the browser (tree view) and select Beam. In a later step, we are going to 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), and is therefore torsionally stiff. Trusses do not have rotational DOF.
Right-click the Element Definition heading for Part 6 in the browser and select Edit Element Definition.
1. Click in the first row of the Sectional Properties table and select Cross-Section Libraries.
  - Select the Round option in the drop-down box at the upper-right corner.
  - Type 0.5 in the Radius (R) field. The cross-section is arbitrary and is intended only to provide a relatively rigid joint.
  - 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 select the option, a pop-up message appears. Click OK to dismiss the message.
3. In the Advanced tab, activate the Large rigid body rotation check box. This implements an alternative beam element formulation, and this option is necessary to ensure accurate stress results when the beams will experience rigid body rotation.
4. Click OK to accept the element definition.