Investigation of the accuracy of different finite element model reduction techniques

In this paper, various model reduction methods were assessed using shear frame, plane, and space truss structures. These structures are one-dimensional, two-dimensional and three-dimensional, respectively. Three scenarios namely poor, better, and the best were considered for each of the structures where 25%, 40%, and 60% of the total degrees of freedom (DOFs) were measured in each of them, respectively. Natural frequencies of the full and reduced order structures were compared in each of the numerical examples to assess the performance of model reduction methods. Generally, it was found that the system equivalent reduction expansion process (SEREP) provides full accuracy in the model reduction for all of the numerical examples and scenarios. Iterated improved reduced system (IIRS) was the second-best, providing acceptable results and lower error in higher modes in comparison to the improved reduced system (IRS) method, although Guyan