Comparison of modal parameters of a concrete slab floor from ema and oma

Document Type

Conference Proceeding

Publication Date



Department of Mechanical Engineering-Engineering Mechanics


In this study, the modal parameters of a hallway floor in Goodwin Hall are compared with experimental modal analysis (EMA) and operational modal analysis (OMA). A set of 17 high sensitivity accelerometers mounted to structural beams under the floor of the hallway will be used to measure the floor response. In EMA an instrumented hammer was used to measure the input, while in OMA ambient excitation was used to excite the floor. The natural frequency, damping ratio, and mode shape estimates for the first five modes of the floor will be compared between the two methods. Despite limitations with generating enough energy to excite standing waves, the modal parameters between EMA and OMA match well. Frequency differences are less than 10%, and all the damping ratio estimates between 2% and 10%. Mode shapes also match well visually, and the MAC shows agreement between methods. Both EMA and OMA show the ability to extract modal parameters from the floor, where the mode shapes show global motion of the floor instead of only local motion between supports.

Publisher's Statement

© 2021, The Society for Experimental Mechanics, Inc. Publisher’s version of record: https://doi.org/10.1007/978-3-030-47634-2_27

Publication Title

Conference Proceedings of the Society for Experimental Mechanics Series