Flexible Components in MotionView
MotionView allows you to create non-linear, flexible components that make use of the ANCF in two ways.
- By creating atomic components composed of BEAM or CABLE elements. You have to specify the geometric and material properties for the flexible components, and connect these components to the rest of your MBS model. This can be achieved through the Body panel. For more details, please refer to the MotionView documentation on NLFE bodies.
- By using the pre-defined sub-systems. In this way, you can create stabilizer bars, coil springs and belt pulley systems with minimal effort. MotionView provides you with a customized GUI for each of these systems that takes care of defining the relevant geometric and material properties as well as creating and assembling the system.
When using the first method to create NLFE components, you have to specify a list of points for the profile of the BEAM or CABLE that you will create. MotionView fits a cubic spline through these points to generate the NLFE component. As with any cubic spline fitting algorithm, there are certain areas to take care of while specifying the profile points.
Consider, for example, the profile points (in red) as defined in Figure 1 below:
Figure 1. A Desired Profile for the Flexible Component
As can be seen, there is a sharp corner in the profile shown above. Using these points as is will result in the following NLFE component:
Figure 2. The NLFE Component Created by Using the Same Profile Points
Figure 3. The Overshoot is Reduced by Adding More and More Points Near the Corner
The disadvantage of this approach is that by adding more points, you are creating more BEAM/CABLE elements which will increase the simulation time in general. If you want to avoid doing this, you can make use of the CONN2 connector element that is used to connect structurally discontinuous NLFE elements. In this scenario, you would define two different NLFE components and connect them as shown in Figure 4.
Figure 4. Using a CONN2 Element to Connect Structurally Discontinuous NLFE Components