Modeling of piping system with dynamic vibration absorber using CAESAR II

Vibrations exceeding the permissible limits in piping systems causes cyclic loads that lead to fatigue, damage, and fracture. The present study addresses vibration reduction in an actual piping system in a petroleum refinery. CAESAR II was used to model the piping system based on the maximum displacement and the corresponding frequency. The stresses exerted on the flanges and supports, displacements, natural frequencies, and system mode shapes are obtained from dynamic analysis. To reduce vibrations, we propose a cantilever beam with a lumped mass at the free end (named a “beam DVA” in this paper) as the vibration absorber. CAESAR II’s dynamic analysis results indicate that using an optimal beam DVA can lower pipe displacement by 73%. Next, the beam DVA is constructed and installed in the actual piping system to validate the modeling results. Experimental measurements show that installing the beam DVA reduces the vibration level of the pipe by 69%. Hence, a good agreement exists between the modeling and experimental results.