The effect analysis of the stiffness changes of a Traditional Fishing Boat Foundation on Vibration Amplitude
| Main Author: | Lekatompessy, Debby Raynold |
|---|---|
| Format: | Article info application/pdf eJournal |
| Bahasa: | eng |
| Terbitan: |
Diponegoro University
, 2021
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| Subjects: | |
| Online Access: |
https://ejournal.undip.ac.id/index.php/teknik/article/view/30978 https://ejournal.undip.ac.id/index.php/teknik/article/view/30978/19408 |
Daftar Isi:
- The ship with the outboard engine is intended to make it easier for fishers to operate and maintain. However, the magnitude of the vibration due to the excitation of the engine during operation adversely affects the surrounding structures. It is evidenced by measuring the vibration amplitude of more than 0.02 mm at several points around the ship engine foundation. This study aims to reduce these vibrations by changing the canal's dimensions as a foundation and using damping rubber as the simplest solution. The analysis was carried out by calculating the vibration parameters of 2 types of machines, SR1110 and S1100. The numerical method is used to calculate the vibration's amplitude by varying the value of channel stiffness and rubber damping on the machine foundation. Supporting data is obtained by measuring the vibration amplitude at several points around the foundation. The magnitude of the previous vibration amplitude is 0.078 mm for the SR1110 type and 0.069 mm for the S1100 type, which exceeds the limit still. The amplitude is reduced by changing the foundation's dimensions and using a rubber damper (c). With the new foundation dimensions, the amplitude for the diesel engine type SR1110 becomes 0.0245 mm and type S1100 becomes 0.0238 mm. Increased stiffness and the addition of rubber succeeded in reducing the vibration amplitude by a significant value. The amplitude was reduced by 69% for the SR1110 engine type and 65% for the S1100 engine type within the allowable limit of less than 0.02 mm to 0.03 mm based on Barkan's observation results.
- Kapal dengan posisi motor penggerak di atas (outboard engine) dimaksudkan agar memudahkan nelayan dalam pengoperasian maupun perawatannya. Tetapi, besarnya getaran akibat eksitasi mesin saat beroperasi berdampak buruk terhadap struktur di sekitar. Hal ini dibuktikan dari hasil pengukuran amplitudo getaran mencapai 0,078 mm pada pondasi mesin kapal. Penelitian ini bertujuan mengurangi getaran tersebut dengan merubah dimensi kanal, serta penggunaan karet peredam sebagai solusi paling sederhana. Analisis dilakukan dengan melakukan perhitungan parameter getaran terhadap 2 jenis mesin, SR1110 dan S1100. Persamaan analitik digunakan untuk menghitung amplitudo getaran dengan melakukan variasi nilai kekakuan kanal dan redaman karet pada pondasi mesin. Data pendukung diperoleh melalui pengukuran amplitudo getaran pada pondasi kapal. Besar amplitudo getaran sebelum adalah 0,078 mm untuk tipe SR1110 dan 0,069 mm untuk tipe S1100 masih melebihi standar. Amplitudo berkurang dengan merubah dimensi kanal serta menggunakan karet peredam (c). Dengan dimensi pondasi yang baru, besar amplitudo untuk mesin diesel tipe SR1110 menjadi 0,0245 mm dan tipe S1100 menjadi 0,0238 mm. Peningkatan kekakuan dan penambahan karet berhasil mengurangi amplitudo getaran dengan nilai yang cukup signifikan. Amplitudo berkurang sebesar 69% untuk tipe mesin SR1110 dan 65% untuk tipe mesin S1100 memenuhi batas yang diijinkan yaitu 0,02 mm s/d 0,03 mm berdasarkan hasil observasi Barkan.