Dynamic Analysis - Water hammer in pipeline

Hi:

I have a buried model pipeline, I want to make a dymnamic analysis of water hammer when Valves close for a signal of leak detection system. When I make a buried model pipe in Caesr II, the software breaks large elements in a little ones and put springs in each node, but this is a no lineal model. It is possible to make a water hammer analysis by dynamic module, using for exmaple the output of Olga, about location and pressure pick.

- How Caesar II takes the fluid density since in a buried model, density is zero?

- Is it a good approach to use buried model for dynamic analysis?

Please your comments,

Best regards,

Luis F.

In a buried pipe ananlysis, you're trying to simulate a beam on a continuous elastic foundation. The only way to do that with a "3D beam element" program such as c2 is to re-mesh the model such that the resulting element lengths and associated restraint stiffnesses approximate the behavior of the soil (which you define). In such a model, there will be no weight stresses - because the beam in reality is continuously supported. This is why all densities are reset to zero when the model is buried.

A consequence of this is that you can't perform a dynamic analysis (because all the weights are zero).