A load-displacement curve is generated and the simulated strength is compared to the experimental strength.
Load-displacement plots are commonly used as tools to determine the global stiffness response of a structure. They are particularly useful for progressive failure analyses as they are a simple means of determining how the structure behaves as failure initiates and progresses. To generate a load-displacement plot, data must be extracted from the output file.
- Select . In the dialog box that appears, select the ODB field output option and click Continue.
- In the dialog box that appears, select Unique Nodal for the Position and check the RF2 and U2 checkboxes. On the Elements/Nodes tab, click Node sets and select LOAD_NODE.
Note: Due to the equation constraint defined earlier, the total reaction force can easily be determined from just the load node.
- Click Save.
- Select . In the dialog box that appears, there will be two sets of data. To write this data to a file, it must be renamed using the Rename button.
- After the data is renamed, it can be output to a text file by selecting . The data can then be plotted using a variety of tools such as Microsoft Office Excel.
The plot of the load-displacement curve is given in below. The sharp drop in stiffness at a displacement of 0.0462 corresponds to ultimate failure of the plate. The simulated ultimate load is 10,769 lbs and the strength is 49.9 ksi. The experimental [1] strength of the plate is given in the table below as 50.5 ksi. The ultimate strength predicted by Helius PFA and the experimental strength differ by just 1.2%.
