Hi,
I am wondering if someone could advise me as to how to combine the moving loads with other loads in the analysis.
I have a beam with moving loads. the other loads being self weight and a UDL of 100kN/m.
Because moving loads generate multile steps (say I have created 20 steps) therefore if I form a combination and ask moving load to be combined with other loads then StaadPro will combine 20 no. moving loads with other loads. Therefore effects of moving load will be considered 20 times!!
Is there a way to combine WORST output from moving load case with other applied loadings?
Please advise. Model is attached.
Thanks.
You should use the ADD LOAD option as explained below for combining other existing load cases with generated moving load cases. If you need to add multiple such cases to the generation, you have to ensure that you define REPEAT LOADs ( and not LOAD COMBINATION ) for combining the primary loads and then add that REPEAT LOAD with the generated moving load cases. For example if you have a situation where you would like to add dead load ( load case 1 ) and imposed load ( load case 2) with the generated moving load cases, you would first define a REPEAT LOAD ( load case 3) which would combine the loads 1 and 2. Subsequently this load 3 would be added to each generation of the moving load case as explained next.
LOAD 1 DEAD LOAD
SELFWEIGHT Y -1
LOAD 2 IMPOSED LOAD
MEMBER LOAD
1 TO 6 12 TO 17 23 TO 28 34 TO 39 45 TO 50 UNI GY -1
LOAD 3 DEAD + IMPOSED
REPEAT LOAD
1 1.0 2 1.0
LOAD GENERATION 10 ADD LOAD 3
TYPE 1 7.5 0 0 ZINC 10
Thanks. But we are still using ALL of the generated loads (ie created during multiple steps)!
I was wondering if there is a COMMAND available within Staad that selects the worst reported results from all loads generated.
Yes it will generate load cases for different positions of the vehicle. You can then see the max moments, shears for these generated cases by using the post processing tables which has Summary tabs and these summary can be based on only the generated cases. For example if you would like to get the max beam end force out of all of the generated cases, you would go to the Beam End Forces table and go to the Summary tab. Right click and choose Results Setup and select only the generated cases to have the summary modified based on just the generated cases. That way you can get min & max Fx, Fy, Fz, Mx, My & Mz out of all of the generated cases.