A Wavelet-Based Approach for Generating Individual Jumping Loads

This paper suggests an approach to generate human jumping loads using wavelet decomposition and a database of individual jumping force records. A total of 1201 individual jumping force records of various frequencies were first collected. For each record, every single jumping impulse was extracted and decomposed by DB10 Wavelet into seven levels, and all the related decomposition information was stored into a database. The period of each jumping impulse in the same record was found to follow a normal distribution, and so does the contact ratio. In order to generate a jumping load time history having N impulses, Wavelet coefficients are first randomly selected from the database for different levels. They are then used to reconstruct N impulses by inverse wavelet transform. The periods and contract ratios are then randomly generated according to their probabilistic function. These parameters are assigned to each of the N impulses. The final jumping force time history is obtained by linking all the N impulses end to end. Examples are presented to show the simulation procedure. Due to the application of the Wavelet decomposition, the non-stationary features of the jumping load force in time-frequency domain can be preserved by the suggested simulation approach.