In dynamic analysis CAESARII considers those +Y supports as active supports which are load carrying in -ve Y direction in the case which is used in the dynamic module. During dynamic analysis all these supports are converted to linear supports as Y. But they are not really Y or even hold down type as per support standards.If during static analysis load on +Y in downward direction is low or very low (means it has tendency to rise but as per static analysis it is a sitting support ) and as per response spectrum or any other dynamic module a load greater than downward value of load is indicated then the support needs to be modified in piping. Unfortunately not many analysts look at this problem and the support is retained as +Y in piping ( i.e. a shoe support without any hold down arrangement). Refer attached loads file.
Is it possible/ advisable to highlight the same in CAESARII analysis reports in dynamic analysis ? It is understood that the values of Y loads in dynamic analysis are not exactly the values seen by support as per report ( which is valid in static analysis , that support loads are actual loads).
Please advise.

Hi,

Dynamic Loads are without signs.How will you ensure whether the load is in + direction or in -?

Response spectrum evaluated loads are considered in absolute value. Time History calculated loads are algebraic.