In some cases, we want to design the hangers with the given installation load, but when we give the hangers with the initial load(such as,20000N), after the calculation, the load under the "sus" case is not equal to the given value(20000N).My question is that:
1. why it happened?
2. If we want to design the hangers with the given load, how can we get the same load under the "sus" case?

1. Did you check the "Cold Load" at the Hangers tab? If not the operating load will override Operating case you defined. See the help menu at the 'operating load'

2. Easiest way is that you choose 'cold load' and define operating load or just input the number at predefined hanger data, but carefull with the accessory weights that CAESAR II cannot know.

My program is 'hot load',and I just input the number(spring rate &theoreticla cold(installation)load ) at predefined hanger data ,but, after the computation, the value of the "sus"case is not the data of the theoreticla cold(installation)load.

"2. Easiest way is that you choose 'cold load' and define operating load or just input the number at predefined hanger data, but carefull with the accessory weights that CAESAR II cannot know."

So it's not going to be changed by cold load or hot load then.

At the sustain case, hanger load can be different depend on the vertical movement. What's the Vertical movement at your spring point? Isn't the loading for sustained case same as 'theoretial cold load + (displacement X Spring rate)'?

What does your 'Hanger table' say? If the theoretial cold load is different than you define, something wrong.

I see,thank you!