How do you apply a temperature gradient to a BEAM18x element?
In ANSYS Release 11.0 BEAM18x elements, temperatures are input as element body loads at three locations at each end node of the beam. The temperatures are input using the VAL1, VAL2, and VAL3 fields on the BFE command. At each end, the element temperatures are input at the:
` element x-axis (T(0,0)) `> VAL1,
` at one unit from the x-axis in the element y-direction (T(1,0)) `> VAL2,
` and at one unit from the x-axis in the element z-direction (T(0,1)) `> VAL3.
Note: The locations of the specified temperatures in the element Y and Z directions are not the outside surfaces of the beam. The locations are one unit from the centroid in each element direction. These locations may lie within the beam cross-section or outside of the beam cross-section. Those temperature values are used to create the gradient in each direction. The temperatures on the outside surfaces are based on the centroid value, thickness of the beam, and developed gradient.
In the following example, the beam cross-section is a 1x1 square. The temperature at the centroid is specified to be 50, and the temperature at a one-unit distance in the Y-direction is specified to be 150, so the Y temperature gradient is (150-50)/1=100/unit. The distance from the centroid to the outside surface is 0.5 units, so the temperature on the top surface is 50+(100*0.5)=100; the temperature on the bottom surface is 50-(100*0.5)=0.
! HOW TO APPLY A TEMPERATURE GRADIENT TO A BEAM ELEMENT
bfe,1,temp,1,50 ! temperature at centroid of end i - T(0,0)
bfe,1,temp,2,150 ! temperature at unit distance y-distance - T(1,0)
bfe,1,temp,3,50 ! temperature at unit distance z-distance - T(0,1)