A Bottom-Up Approach to FE Model Updating of Industrial Structures

摘要

The main aim of FE model updating is to iteratively correct the inaccurate parameters in a structural model so that the agreement between numerical predictions and modal test results is improved. Modeling the boundary conditions and contact interfaces between the different components is a challenge that needs to be taken into account in regards to the computational cost of the model for the iterative stage of the study. For instance, an extremely detailed model is of no use if each iteration takes hours to solve. A bottom-up approach can be followed to generate a highly accurate FE model by gradually increasing the complexity of the studied structure. This requires of a careful test planning phase to acquire experimental data from the structure in different boundary conditions and assembly stages. An overhead crane runway beam FE model is updated in this study case. Three FE models of increasing complexity in their boundary conditions and contact interfaces are optimized and updated with their three corresponding modal experimental datasets. This bottom-up approach allows dividing a complex problem in smaller phases, which results in a smaller number of design variables present on each model updating cycle. This is essential for the successful application of optimization algorithms with a limited computational power. In a qualitative sense, it allows the analyst to have a deeper understanding of the model from its conception and to have a solid grasp of the different what if scenarios.