A Simulation-Based Method to Detect Mechanical Parameters of I-Beams and Hollow Cylinders

Impulse excitation technique is a simple, convenient, and standard nondestructive method to detect mechanical parameters (dynamic Young’s modulus and dynamic torsional modulus) that only utilizes the first-order flexural resonant frequency, first-order torsional resonant frequency, and dimensions of structures. However, the mechanical parameter detection formulas are well established only for standard uniform specimens with uniform rectangular and circular cross sections. This study suggests a simulation-based method to detect mechanical parameters. A response surface method (RSM) is introduced to design numerical simulation experiments to build up experimental formulas to detect mechanical parameters. Numerical simulations are performed by the finite element method (FEM) to obtain enough simulation data for RSM analysis. After calculations, the two relationships (experimental formulas) can finally be obtained, i.e., the relationship of the dynamic Young’s modulus and first-order flexural resonant frequency with respect to dimensions of structures and the relationship of the dynamic torsional modulus and first-order torsional resonant frequency associated with dimensions of structures. Numerical simulations and experimental investigations show that the simulation-based method can be used to detect mechanical parameters in I-beams and hollow cylinders. More generally, this method can be further developed to detect the mechanical parameters of more complex structures than standard uniform specimens using a combination of FEM simulation and RSM.