122 C. Beale et al. Fig. 11.20 TRAC values computed from the expanded noisy time responses for each test case using the standard generalized inverse approach with no regularization case 4 with noise amplitude 0.040, are provided in Fig. 11.21c. A comparison of the noisy reference response (UN) with the analytical response (U) is shown for each noise case to give a perspective of the noise severity. Similarly, a comparison of the expanded response (EN) with the noisy reference response (UN) is shown for each noise case to show the influences of noise on the expanded results. Considering the least severe noise case (Fig. 11.21b), the noise exhibited on the reference response is negligible relative to the analytical response. The resultant expanded response exhibits a slight increase in noise compared to the noisy reference response, but otherwise correlates well with a TRAC of 0.99. In the most severe noise case (Fig. 11.21c), the noise exhibited on the reference response is discernable, but still small relative to the analytical response. Despite the low relative amplitude of the noise, the expanded results exhibit a large amount of noise resulting in a poor TRAC value of 0.54. Similar to the observations extracted from mode shape expansion, time domain expansion is heavily influenced by noise.
RkJQdWJsaXNoZXIy MTMzNzEzMQ==