One of the components of the Indonesia Tsunami Early Warning System (InaTEWS) is a surface buoy. The surface buoy is exposed to dynamic and random loadings while operating at sea, particularly due to waves. Because of the cyclic nature of the wave load, this may result in a fatigue damage of the keel structure, which connects the mooring line with the buoy hull. The operating location of the buoy is off the Java South Coast at the coordinate (10.3998 S, 108.3417 E). To determine the stress transfer function, model tests were performed, measuring the buoy motions and the stress at the mooring line. A spectral fatigue analysis method is applied for the purpose of estimating the fatigue life of the keel structure. Utilizing the model-test results, the S-N curve obtained in a previous study and the wave data at the buoy location, it is found that the fatigue life of the keel structure is approximately 11 years.

Bahasa Abstract

Prediksi Umur Kelelahan Struktur Keel Buoy Tsunami dengan Metode Spectral Fatigue Analysis. Salah satu komponen dari sistem peringatan dini bahaya tsunami di Indonesia (InaTEWS) adalah surface buoy. Komponen tersebut mengalami beban dinamis dan acak akibat gelombang selama beroperasi di laut. Sifat siklik dari beban gelombang dapat menyebabkan kerusakan kelelahan pada struktur keel. Lokasi buoy adalah (10.3998 S, 108.3417 E). Untuk menentukan fungsi transfer tegangan, suatu percobaan model tes buoy dilakukan untuk mengukur gerakan buoy dan beban gelombang. Dengan menggunakan metode spectral fatigue analysis yang didasarkan pada hasil uji model, umur kelelahan struktur keel adalah sekitar 11 tahun untuk berbagai kondisi laut.


Badan Meteorologi, Klimatologi dan Geofisika (BMKG), InaTEWS (Indonesia Tsunami Early Warning System): Konsep dan Implementasi, Jakarta, 2010 (in Indonesian).

Sahlan, MSc Thesis, Faculty of Marine Technology, ITS Surabaya, Indonesia, 2011 (in Indonesian).

Sahlan, Soeweify, W.H. Putra, I.K. Suastika, W.H. Nugroho, Prosiding Seminar Pascasarjana XI-ITS, Surabaya, Indonesia, 2011, p.381 (in Indonesian).

P.H. Wirsching, M.C. Light, J. Struct. Div. ASCE. 106/7 (1980) 1593.

K. Ortiz, N.K. Chen, Proc. Fifth Int. Conf. on Application of Statistics and Probability in Soil and Struct. Eng., Vancouver, BC, 1987, p.309.

C.E. Larsen, L.D. Lutes, Prob. Eng. Mech. 6 (1991) 96.

J.M.J. Journee, W.W. Massie, Offshore Hydromechanics, 1st Ed., Delft Univ. Tech., The Netherlands, 2001, p.570.

P.D. Welch, IEEE Trans. Audio Electroacoustics, AU-15/2 (1970) 70.

N.D.P. Baltrop, A.J. Adams, Dynamic of Fixed Marine Structures, 3rd Ed., ButterworthHeinemann Ltd., Oxford, 1991, p.740.

Y. Wang, Int. J. Fatigue. 32 (2010) 310.

K.T. Nguyen, Y. Garbatov, C.G. Soares, Int. J. Fatigue. 48 (2013) 147.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.