Experimental and Finite Element Method study on dynamic characteristics of beam-column glulam frame structure

Abstract

In order to strengthen the seismic design and diagnosis of glulam building structures, and improve the accuracy and reliability of building modal analysis, this paper uses the designed glulam frame structure as a research object to conduct experimental investigation on its dynamic properties. On the one hand, a computational modal analysis is carried out using ANSYS to determine the modal shapes and modal parameters of the glulam frame structure. On the other hand, transient excitation, steady-state contact excitation and steady-state non-contact excitation methods are used to test and analyze the experimental modalities of the field-built larch glulam frame structure. The research results show that the three experimental modal methods can all measure the biaxial(xy-) first-order bending, first-order torsion, and second-order bending modes of the glulam frame structure. The vibration shapes and modal frequencies are all consistent. The results of computational modal analysis and experimental modal analysis are combined in this article. Since the elastic constant input of components is measured by grading, the frequency values of the computational mode are larger. The error of the two analyses is about 15%. In the first-order bending mode in the x- and y-directions, both the computational and experimental modes show the characteristics of greater local stiffness in the gusset. In the uniaxial (x- or y-) torsional mode, the computational mode not only reflects the torsional characteristics of the upper beam region, but also shows first-order bending mode of the column, which is also consistent with the experimental mode.