Start Date
13-5-2021 1:50 PM
End Date
13-5-2021 2:10 PM
Document Type
Full Paper
Keywords
Structural health monitoring, Additive manufacturing, hammer impact excitation
Description
Structural health monitoring (SHM) has been used in various engineering sectors such as aerospace and civil engineering applications for reducing maintenance costs and to operate the system safely by detecting faults in the system. Additive manufacturing (AM) was used primarily for prototyping but recently many parts are produced for actual use to benefit from the layer by layer part generations. AM can generate very complex geometries which cannot be manufactured by convention manufacturing. The internal hidden geometry of an AM part can be designed to simplify the defect location estimation by using SHM methods. A PLA cross-shaped part was designed and fabricated by the Fused Deposition Modeling (FDM) method. Each extension of the part had different internal geometry. The part was excited at the center with the impact of a hammer and the response to the excitation was monitored by the attached piezoelectric discs at the end of each extension. The recorded data from sensors were plotted and compared in the time-domain, frequency-domain (Fast Fourier Transform(FFT)), and in the time-frequency domain (Short-Time Fourier Transform (STFT), and the Continuous Wavelet Transform (CWT)). The results showed that the hidden geometry of each extension had a different effect on the wave characteristics. Lamb waves traveles with lower attenuation at sections with higher infill ratio.
DOI
https://doi.org/10.5038/WQVB1653
The effect of hidden geometry on the signal characteristics in additive manufactured parts
Structural health monitoring (SHM) has been used in various engineering sectors such as aerospace and civil engineering applications for reducing maintenance costs and to operate the system safely by detecting faults in the system. Additive manufacturing (AM) was used primarily for prototyping but recently many parts are produced for actual use to benefit from the layer by layer part generations. AM can generate very complex geometries which cannot be manufactured by convention manufacturing. The internal hidden geometry of an AM part can be designed to simplify the defect location estimation by using SHM methods. A PLA cross-shaped part was designed and fabricated by the Fused Deposition Modeling (FDM) method. Each extension of the part had different internal geometry. The part was excited at the center with the impact of a hammer and the response to the excitation was monitored by the attached piezoelectric discs at the end of each extension. The recorded data from sensors were plotted and compared in the time-domain, frequency-domain (Fast Fourier Transform(FFT)), and in the time-frequency domain (Short-Time Fourier Transform (STFT), and the Continuous Wavelet Transform (CWT)). The results showed that the hidden geometry of each extension had a different effect on the wave characteristics. Lamb waves traveles with lower attenuation at sections with higher infill ratio.