Simulasi pengurangan getaran sendiri di sebabkan oleh kesan aeroelastik dengan menggunakan tampalan piezoelektrik di laporkan. Fokus kerja ini ialah simulasi pengurangan ayunan flutter menggunakan tampalan piezoelektrik terhadap struktur sayap. Pertama, sayap yang bersih di dedahkan kepada aliran udara dalam terowong angin di mana ianya mengalami getaran amplitude yang terhad. Tindak balas tersebut di rekodkan. Kemudian, tampalan piezoelektrik ke atas struktur sayap di lakukan dan di uji semula. 2 tampalan tersebut digunakan sebagai penggerak untuk tujuan simulasi fenomena flutter. Mod yang di pilih ialah mod lenturan pertama. Dua lagi tampalan piezoelektrik digunakan untuk pengurangan bagi kawalan aktif menggunakan maklum balas negative input tunggal-output tunggal. Sistem kawalan ini berjaya menguruskan simulasi pengurangan flutter kepada getaran rendah amplitud. Tambahan, analisis getaran juga di lakukan dengan menggunakan perisian ANSYS 15.0 dan eksperimen analisis modal bagi mendapatkan sifat-sifat getaran seperti nisbah redaman, kekerapan semula jadi, dan mod bentuk. Teori Euler-Bernoulli juga di gunakan untuk menganggarkan kekerapan lenturan. Hasil-hasil analisis ini di gunakan bagi menganalisis sikap struktur sayap. Secara kesimpulan, kerja ini ialah untuk demonstrasi penggunaan bahan piezoelektrik sebagai penggerak untuk menghasilkan getaran amplitude yang terhad dan pengurangan getaran tersebut pada masa yang sama.
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Suppression of simulated self-excited oscillation due to aeroelastic effects using piezoelectric patches is reported. The focus of the present work is suppressing simulated flutter oscillation using piezoelectric patches bonded to the wing structure. First, a clean wing is exposed to airflow in the wind tunnel where it experienced limited amplitude oscillation. The responses were recorded. This is followed by bonding piezoelectric patches to the wing surface that was tested in the wind tunnel. Two of the patches were used as actuators to simulate self-excited oscillation in a control manner. The selected mode for excitation is 1st bending mode. The other two patches were used as suppressor for active control using negative velocity feedback Single-Input, Single-Output approach. The single input signal for negative feedback is also sensed using piezoelectric patches. The controller manages to suppress the simulated flutter response to a lower oscillation amplitude values. In addition, vibration analysis were done using ANSYS 15.0 software and experimental modal analysis in order to obtain vibration characteristics such as damping ratio, natural frequencies and mode shapes. Euler-Bernoulli beam theory also was used to estimate the bending natural frequencies of the wing structure. These results were compared to analyse the behaviour of the wing structure. In conclusion, this works demonstrated the used of piezoelectric material as actuator to reproduce the limited oscillation amplitude during self-excited oscillation and suppress the oscillation at the same time.
Suppression of simulated self-excited oscillation using smart materials on flexible wing structure / Nazreen Shah Nasip