SICODYN international benchmark on dynamic analysis of structure assemblies: variability and numerical-experimental correlation on an industrial pump (part 2)

Abstract

An international benchmark has been organized by EDF R&D during 2008−2010, gathering 11 partners. Its main objective is to quantify the confidence in numerical models. The built-up dynamical system considered is a pump actually in service in power plants, considered in its work environment. Blind eigenfrequency numerical values relative to the pump assembly fixed in concrete present a larger variability than the 5% rough variability concerning the separate parts, essentially due to the modeling of the boundary conditions and interfaces at macro level. For the nine first eigenmodes considered, experimental-numerical correlation shows a frequency error less than 15% for the free sub-structures and nearly 30% for the free five-component system. Though the first overall modes are correctly identified, the frequency error is significantly larger for the clamped pump assembly, with however MAC coefficients higher than 0.9 for two modes; but the frequency error can be reduced to less than 9% for the four first modes after updating procedure. A lesson to draw is that measurement information is needed to improve the quality of theoretical built-up structure. After this benchmark, a more ambitious research program will follow as a FUI project, gathering the observation of numerical and experimental variabilities, updating model improvement and numerical quantification of the total uncertainty.

Robust characterization of the vibrational behaviour of light assembled structures with random parameters

“…Considering light structures enables us to ensure a well-known behaviour. Extension on massive 3D assembled structures (such as [13,14]) could be easily considered but will not be addressed in this paper.…”