Hi

How to input cyclic loading in PVElite

Hi there Saswat

Before any fatigue calculation can be accomplished, the programme needs to have the pressure / cycles data. This is how to do it:

Firstly, go to the Contraints screen. On the right hand side of the Contraints screen you will see a button called 'Perform Fatigue Analysis ?'. Click on this button. You will be presented with a spreadsheet type screen, with three columns and a number of rows. At the top of this screen, enter then number of pressure/cycle groups you would like the programme to analyse. Enter a number (between 1 and 20). In the first column enter the low pressure, in the second column enter the high pressure, and in the third column, enter the number of cycles. Do this for each case. For example, you may wish for one case to have the following: From 25 psi to 75 psi cycled 15 000 times. The programme will calculate the range (50 psi in this case).

Now we need to know which nozzles are to be analysed for this fatigue set.

When you enter the nozzle data in the nozzle dialogue box (when you enter all the nozzle data), there is a check box at the bottom right hand corner of this dialogue box called 'Perform Fatigue Calc?'. Check this box. If you are performing a PD5500 or EN13445 calculation, you will have to set the correct 'Weld Class' which is available from a drop down list box just to the right of the fatigue check box.

Now if you run the calculation, you will see a fatigue section in the output list. The fatigue is performed for all the nozzles for which the fatigue check box is checked.