Finite element and isogeometric correlation analysis using Modal As-surance Criterion
Keywords:finite element, isogeometric analysis, modal assurance criterion, structural dynamics
In the present work we propose to compare the conventional finite element analysis and isogeometric analysis methods. We explore these two modeling methods in the same application in order to identify their differences. From the analytical point of view there is a difference in the type of the shape functions, the Lagrange polynomials used in finite element analysis interpolate the nodal points, and are C0 continuity at the nodal points, in the isogeometric analysis, the NURBS basis functions (Non Uniform Rational B-Spline) have a high continuity and do not interpolate control points. For the comparative study of the two modeling methods, we chose the standard Modal Assurance Criterion (MAC) to compare the eigenmodes. Because of the equality of the first order Lagrange polynomials and the first order NURBS functions, we obtain a perfect eigenmodes correlation of the two methods, but the correlation for the second order shows a slight difference, which highlights a different classification of the two modeling methods.