Support stiffness effects on piping dynamic response

A typical assumption employed in production piping analysis is to assume that struts, rod hangers, and other so-called rigid restraints may be modeled with either infinite or very large stiffness values. Recent research indicates that this may not be appropriate. We review conclusions derived both from the literature and from studies by the authors about the effect of neglecting these stiffness values. We then suggest a method to check the assumption's validity in the form of a simple equation. (orig.)