I need to analyse a deck slab for a temperature change of plus or minus 60 degrees F. In addition, there is a temperature gradient of 25 degrees F between the top and bottom surfaces of the slab. How do I do this? The slab has been modelled using plate elements.
Related question :
How would I enter the temperatures in the dialog boxes in the Staad program.
1) Temperature change for axial elongation2) Temperature differential from top to bottom3) Temperature differential from side to side (local Z)
Below is my situation:
Inside temperature = 650 DegFOutside temperature = 50 DegF
I have entered the inputs different ways and could not get the reasonable results that I expect.
Would you advise me how the data should be entered.
If we assume that the temperature at the stress-free condition is A, then, the structure must be analysed for 2 conditions, each of which must have its own load case.
Condition 1 :-------------
a) temperature at the top of concrete reaching (A + 60 + 12.5)b) temperature at the bottom of concrete reaching (A + 60 - 12.5)
Assuming that your plate elements all have the local Z axis pointing along the global Y direction, you specify this using the syntax
element-list TEMPERATURE 60 25
The first number (60) is equal to the average temperature you want to design for minus the temperature corresponding to the stress-free condition. The second number is the temperature of the top surface (the fiber at the +Z surface) minus the temperature of the bottom surface (fiber at the -Z surface). Hence, it is important that the +Z surface correspond to top-of-deck.
LOAD 10 TEMPERATURE INCREASETEMPERATURE LOAD501 TO 588 TEMP 60 25
Condition 2 :-------------
a) temperature at the top of concrete reaching (A - 60 - 12.5)b) temperature at the bottom of concrete reaching (A - 60 + 12.5)
The syntax for this is
element-list TEMPERATURE -60 -25
LOAD 11 TEMPERATURE DECREASETEMPERATURE LOAD501 TO 588 TEMP -60 -25
1) The term in the dialog box "Temperature differential from side to side (local Z)" is applicable only for members (line entities used to represent beams, columns, etc.). It is not relevant for plates.
2) For an example problem that illustrates the application of temperature loads on plates, please go to STAAD.Pro Help section Tutorials > T.3 - Analysis of a slab > T.3 Creating the model using the analytical user interface > T.3 Specifying Primary Load Cases.