BEAM T-JUNCTION MODEL ACCURACY IMPROVEMENT
BASED ON EXPERIMENTAL MODAL ANALYSIS |
Francisco Badea 1, JesusAngel Perez 2, JoseLuis Olazagoitia 1 |
1Industrial Engineering and Automotive Department, Universidad Nebrija 2Industrial Engineering, Oviedo University |
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ABSTRACT |
For structural analysis of bus and coach tubular structures, finite element analysis with beam type elements is
widely approved and utilized. These elements have an infinitely rigid behavior at the joint level, which represents an
unrealistic stiffer estimation of the modeled structures. This cannot be neglected since it introduces stiffness variations when
analyzing complex structures. To overcome this limitation, in this article an alternative beam T-junction model, in which 6
elastic elements are included at the joint level in order to improve the local stiffness behavior, is utilized. A new methodology
to determine these 6 elastic constants is proposed, based on the analysis of the modal response differences between the beam
model and the real prototype T-junctions. In this way, a completely new methodology for the determination of the rigidity of
the elastic elements based on the analysis of the modal characteristics of these structures is presented. The methodology is
validated against experimental modal analysis. The results show that using this methodology with the alternative beam
T-junction model is possible to obtain a more accurate T-junction model with an average deviation from real models of less
than 1.5%, and a maximum deviation among the studied modes of less than 4. |
Key Words:
Modal analysis, Structural optimization, Elastic constants, FEM improvement, T-junction |
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