MSC Patran Command Language

Aircraft Structural Analysis using Nastran Patran

Patran Command Language is a great tool for enhancing the capability of Patran. The Company provides custom PCL code for client applications, which appear as pull down menus (Graphic User Interface) in client's Patran window.

Structural Analysis of Airframe Parts

Current Process (both for metallic and composite parts):

1. Patran is used for pre and post processing

2. Results are output in graphical form manually and pasted in MS Word

3. Numerical Data from Patran is compared to Design Allowables to calculate Margin of Safety (using hand Calculator)

4. After load data is updated, steps 1 to 3 are repeated (it takes weeks and sometimes months to update stress reports)

PCL (Patran Command Language Applications)

New Approach :

1. Generic PCL code is developed for use on any Patran model for output of screen data and report data.

2. User creates appropriate groups for generating deformation, fastener loads and stress data.

3. Pull Down Menus (Graphical User Interface GUI) are developed to avoid running text based scripts. (similar to Patran Utilities option)

4. The output from Patran is read directly in MS Excel using generic Visual Basic (VBA) code

5. Design Allowables are part of VBA and Margin of safety is calculated at the click of button

6. Stress report is updated in a few minutes !!

PCL (Patran Command Language Applications)

Current Approach (Composite Parts -- Laminate & Sandwich):

1. For each zone the user plots the layers and then determines the critical zones

2. User needs to know number of layers for each zone.

3. If there are 10 zones (both laminate and sandwich), user needs to know which zone is laminate and sandwich before plotting the data.

4. Patran will show for user selection the total number of layers in the model, irrespective of the fact the zone/ group selected. User has to plot both outer most and the next layer to determine the critical element.

5. If there is an error in the model or inputs, user has to plot the data again manually.

New Approach (Composite Parts -- Laminate & Sandwich):

1. PCL determines, which group is laminate or sandwich and outputs the data for the critical element (both screen data and report data from Patran) automatically (based on user selection of the group / zone).

2. The screen data and the report data are read directly in MS Excel using VBA script.

3. The margin of safety are updated at the click of a button.

Download Stress and Strain Data

Airframe Sizing, Fatigue and Aero Elasticity