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Rectangular-Plate Parametric Study EASAP

Often an optimization problem involves finding a 'best' output by conducting a search through the space of possible inputs.

  • For a single-input problem the task is straightforward,
    • Try an input
    • Record the output
    • Try a new input value…

As more tries are recorded, the new input 'guesses' can be chosen closer in value to those that produced the most optimal outputs during the prior attempts.

For multiple inputs the problem space expands exponentially, gaining insight about an optimal solution requires a brute-force search involving many runs with many input combinations.

Parametric studies allow a long list of varying inputs be submitted at one time. Processing may be prolonged but—for example—the User may complete other tasks while the results are written to a database for later retrieval. EASA lets you do 'slow' things in the background.


RectangularPlateParametricListStudy.easap

In this example, above, we take an Excel spreadsheet with a list of Length, Thickness and Uniform Load values and run a version of the Cantilever Plate Tutorial EASAP that has been modified to take multiple-run or 'parametric study' inputs. Results from each run are written to a database.

The EASAP requires the User select a loads file( plate_loads.xlsx in this example) then click Upload. The parametric inputs populate the table. Individual inputs for each run can be added, deleted or modified via the 'Edit' tab.


Please download and unzip: http://help.myeasa.com/resource/easap/6_1/Parametric_Plate.zip

We now have:

  • plate_loads.xlsx → spreadsheet with a eighty rows, each corresponding to a 'run'
  • plate.bak → a database for the results
  • Parametric_Plate.xml → database configuration details
  • RectangularPlateParametricListStudy.easap → completed EASAP to examine and run

Setting up the database

  • Download, install and open SQL Server Express
  • Right-click Databases
    • Select Tasks→Restore→Database
    • Set Destination→Database:Parametric_Plate
    • Set the Source→Device radio button
      • Navigate to the unzip'd plate.bak file
  • Check the Restore box on the appropriate 'backup set' if more than one
  • In the same window:
    • Select Options and check 'Overwrite the existing database (WITH REPLACE)'
  • Click OK

The database has been 'restored'.

  • 'Map' the database user to the database: on our case its easa.
    • Select Security→Logins→easa
    • Right-click Properties
    • Under User Mapping menu tick 'Parametric_Plate' to add easa user.

Now we import Parametric_Plate.easap.


Importing Parametric_Plate.easap

  • Login to the EASA Server
    • Select EASA→Set Mode→Author
  • Select the tab:
    • EASA→Applications→Import EASAPs
  • Click Choose File
    • Browse to Parametric_Plate.easap
  • Click Import

Now we configure the database and driver on the EASA Server


Configuring a database connection in EASA

  • Copy Parametric_Plate.xml to:
    • EasaServerData\easa-share\naming\jdbc\

The settings in this file will help configure EASA Server database connection, below.

  • Select EASA→Set Mode→Administrator
  • Select EASA→Configure→Databases→Configure Drivers
    • Choose File then Upload for the jdbc driver
  • Select EASA→Configure→Databases→Configure Databases
  • Select New Database
  • Set the various fields to the values in Parametric_Plate.xml
  • Restart EASA Server if a new driver
  • Select EASA→Set Mode→Administrator→Configure→Databases
    • Confirm Test Query works for Parametric_Plate

Running RectangularPlateParametricListStudy.easap

  • Select EASA→Set Mode→Author
  • Select EASA→Applications→My EASAPs
  • Select Rectangular Plate (Parametric List Study)
  • Select EASA→Authoring→Testing→Test EASAP

The main table will be empty until the 'loads' spreadsheet has been uploaded.

The table will be populated with length,thickness and uniform load inputs.

Select a row and click 'Edit' to modify the values from Excel.

'Submit' begins the lengthy process of running each of the eighty runs.

A POLL REQUEST EVENT updates a counter showing the fraction of completed runs.