PSI - Issue 52

Dong Xiao et al. / Procedia Structural Integrity 52 (2024) 667–678

675 9

Dong Xiao et al. / Structural Integrity Procedia 00 (2023) 000–000

Fig. 5: FE model validation

Fig. 6: Impact simulations

4. Results

4.1. Validation of loading and unloading frequency constraints

By applying CWT to the responses of target impact, the dominant frequency f d of the responses can be identified. Figure 7 illustrates the experimental impact responses recorded by each sensor, impact force and the CWT magnitude scalogram. The CWT magnitude scalogram’s amplitude, which is the product of CWT coe ffi cients for all 4 sensors’ responses, is used for dominant frequency analysis. The impact dominant frequency with maximal CWT amplitude, was identified as ˆ f d = 77 Hz , with an uncertainty bound of [68 , 84] Hz . The corresponding contact duration estimation was given by ˆ T = 1 / ˆ f d = 13 ms . This estimated contact duration ˆ T was very close to the actual contact duration T = 13 . 2 ms identified from experimental impact force history. These results indicate that the dominant frequency analysis based on the impact responses can accurately identify the actual impact duration. Furthermore, when combined with the impact force parameterization method, the dominant frequency serves as a precise approximation of the harmonic average of the loading frequency and unloading frequency. The loading and unloading frequency bounding method based on the dominant frequency has been verified to be both precise and e ff ective.

(a) Impact responses and force

(b) Impact dominant frequency estimation

Fig. 7: Impact dominant frequency analysis