Basic Question - Scale Factor for Buckling Results

[rdias66]

Hello,

I'm not sure what I should be comparing my buckling results to. What is the definition of the scale factor? I understand it is the buckling load in comparison to the applied load, but my loads vary along the model and it's an tri-axial ellipsoid. So how can I understand which applied load it is referring to?

I understand the basics of buckling analysis, but because of the shape of the model I don't know how this translates. I've applied surface pressures.

Thank you.

Raquel

 

[MengBob]

The scale factor means that buckling occurs if the applied loads are scaled by this.

 

[rdias66]

I understand that, but what exactly do I specify as the applied loads? Is it the locally applied loads? If I'm using combinations loads SAP2000 doesn't seem to have a way of showing what the resultant loads are for each shell area, so how can I know what the applied load is for a specific shell element that has caused it to buckle?

I considered the following option: Sum the base reactions and divide it by the area of the ellipsoid to give an average applied pressure, the use this multiplied by the scale factor to find the critical buckling load. But it is giving me much larger values than the predicted limiting buckling load.

 

[stressed]

I don't understand your question. The buckling load case dialogue enables you to specify the applied loads to be used in each buckling case. For each of those loads or load combinations, output is available to check element shears, moments, stresses, deflections, and joint reactions. You can also check assigned loads for each element by right clicking them individually, using the interactive database tables, or using Display tables.