Modal analysis of feed water pipe line RL61 at the Loviisa NPP

The main aim of this project is to develop a practical method for monitoring the condition and remaining lifetime of process piping. The computational model is updated through measurements, but in practice both measurements and testing are often quite limited. Numerical pre-analyses were performed to optimise the use of resources available for testing. Optimal locations for the transducers and the shaker were predicted numerically using the ABAQUS Finite Element (FE) and FEMtools programs. It is important to select the optimal measurement method for each case. Both hammer excitation and shaker excitation were used when analysing modal shapes by measurement. Some preliminary evaluations of these results are presented here. (orig.)