Estimation of the state of rod structural elements based on recording of deformation responses to serial impact excitations

Based on the example of welded and one-piece-cut steel (Steel 10) frame triangular elements (4 × 8 × 245 mm) using the methods of thermal unloading up to the temperature T _max = 625°C, serial impact testing of parent (stressed) and unloaded elements, and comparative analysis of Fourier images of deformation responses with respect to unloaded elements, it was found that a nonlinear region of the Fourier image degenerates into a linear one and the maximum of the linear regions of the Fourier image shifts up to 2 Hz. The dynamic deformation responses of the elements were recorded using superbroadband (from 10⁻² to 10⁸ Hz) ferroelectric microsensors based on thin Pb(Zr_0.53Ti_0.47)O₃ films with a thickness of ∼2.0 μm with a 0.8 mm² contact pad. The results can provide a the signal for distinguishing stressed states of structures and their elements.