| This research investigated a real-time identification technique for the prediction of location and force history of low-velocity impacts on composite panels with beam stiffeners. The investigation included both analysis and experiments. Measurements from built-in piezoceramic sensors were used to reconstruct the force history using the smoother-filter algorithm. Impact location was determined by minimizing the difference between modeled response and actual response.; Computer codes were developed for model construction (WFMODEL) and impact identification (WIDIMPACT). The model allowed for the variation of plate structural properties (density and stiffness) due to the presence of stiffeners. Results of extensive experiments verified the model, as coded in WFMODEL, for impacts both in the bay and on the stiffener. The identification technique, as implemented in the code WIDIMPACT, demonstrated real-time capability.; The predicted force histories and locations matched actual values well, including results for different impact masses. The importance of model boundary conditions to the success of the impact identification was demonstrated. Studies showed that for a given size sensor zone, exact sensor placement was unimportant. For smaller impact loads, increased sensor spacing lead to increased impact prediction errors. However, for larger impact load, errors remained relatively constant for several spacing dimensions. |
