The vibration serviceability problem of structures such as building floors, footbridges, large balconies, and monumental stairs due to human movements has become an important issue, which requires careful attention of designers and engineers. Design engineers often create Finite Elements models of structures to predict their dynamic properties and their responses due to human movements. Therefore, one important aspect of the dynamic analysis of structures is the identification and quantification of excitation forces due to human movements. As part of this research study, measurements of ground reaction forces (GRF) from a number of individuals were conducted at the Virginia Tech Vibration Testing Laboratory using an instrumented force platform. The subjects walked at various speeds synchronized using a metronome. The same tests were subsequently repeated while the subjects ascended and descended over an instrumented mock stair. Considering the periodicity of human excitation force, the Fourier Series parameters (Fourier Coefficients and corresponding phase angles) of the measured forcing functions were computed. Correlations between the measured GRF's on a flat surface and an inclined surface (stair) were established. The results of the analysis were compared to the available information in the literature in an attempt to check their accuracy.
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