Analisis Frekuensi Alami Crane Kapal Menggunakan Metode Effective Mass Participation Factor (EMPF)

Saragi, Putra Dame Lamtua (2026) Analisis Frekuensi Alami Crane Kapal Menggunakan Metode Effective Mass Participation Factor (EMPF). Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Struktur tiang crane kapal merupakan komponen utama yang berfungsi menopang sistem crane dalam aktivitas bongkar muat serta menerima pembebanan dinamis akibat pengangkatan beban, perubahan sudut boom, dan gerakan kapal. Pembebanan tersebut berpotensi menimbulkan resonansi apabila frekuensi eksitasi mendekati frekuensi alami struktur, sehingga diperlukan analisis karakteristik dinamis untuk mengidentifikasi mode getar dominan dan mengevaluasi keamanan operasional struktur. Penelitian ini bertujuan menentukan frekuensi alami dan bentuk mode getar struktur tiang crane kapal, mengidentifikasi mode getar dominan menggunakan Effective Mass Participation Factor (EMPF), mengevaluasi Cumulative Effective Mass Participation Factor (CEMPF), serta menganalisis potensi resonansi berdasarkan ketentuan Bureau Veritas (BV Rules 2025) dan American Bureau of Shipping (ABS Rules 2022). Penelitian dilakukan menggunakan metode elemen hingga melalui perangkat lunak ANSYS Mechanical dengan memodelkan struktur tiang crane berbahan baja AH36 berdasarkan geometri crane MHI V6 Series. Sebelum analisis modal dilakukan, studi konvergensi mesh untuk memperoleh ukuran elemen optimum sebesar 200 mm, kemudian diekstraksi 25 mode getar. Penentuan mode dominan dilakukan melalui evaluasi nilai EMPF dengan kriteria EMPF > 1% pada setiap arah translasi, dilanjutkan dengan verifikasi CEMPF hingga mencapai akumulasi partisipasi massa sebesar 80–90%, sedangkan validasi hasil numerik dilakukan menggunakan metode Rayleigh. Hasil penelitian menunjukkan bahwa frekuensi alami terendah diperoleh pada mode pertama sebesar 14,475 Hz dan mode kedua sebesar 14,480 Hz. Berdasarkan evaluasi EMPF, diperoleh lima mode getar dominan, yaitu mode 1, 2, 6, 7, dan 8, yang memenuhi kriteria partisipasi massa signifikan dan telah merepresentasikan karakteristik dinamis struktur melalui pencapaian nilai CEMPF. Evaluasi terhadap frequency separation menunjukkan bahwa mode 1 dan mode 2 berada pada kondisi yang berpotensi mengalami resonansi, sedangkan mode 6, mode 7, dan mode 8 memenuhi persyaratan BV Rules 2025 dan ABS Rules 2022. Validasi menggunakan metode Rayleigh menghasilkan selisih sebesar 8,99% terhadap hasil FEM, sehingga model numerik dinilai mampu merepresentasikan karakteristik dinamis struktur tiang crane kapal dengan baik.
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The ship crane mast is a primary structural component that supports the crane system during cargo handling operations and is subjected to dynamic loads caused by lifting operations, boom angle variations, and ship motions. These dynamic loads may induce resonance when the excitation frequency approaches the natural frequency of the structure. Therefore, a dynamic characteristic analysis is required to identify the dominant vibration modes and evaluate the structural safety during operation. This study aims to determine the natural frequencies and mode shapes of a ship crane mast, identify the dominant vibration modes using the Effective Mass Participation Factor (EMPF), evaluate the Cumulative Effective Mass Participation Factor (CEMPF), and assess the resonance potential based on the requirements of the Bureau Veritas (BV Rules 2025) and the American Bureau of Shipping (ABS Rules 2022). The study was conducted using the Finite Element Method implemented in ANSYS Mechanical by modeling an AH36 steel crane mast based on the geometry of the MHI V6 Series crane. Prior to the modal analysis, a mesh convergence study was performed to determine the optimum element size of 200 mm, followed by the extraction of 25 vibration modes. The dominant modes were identified by evaluating the Effective Mass Participation Factor (EMPF) using the criterion of EMPF > 1% in each translational direction, followed by verification of the Cumulative Effective Mass Participation Factor (CEMPF) until the cumulative participating mass reached 80–90%. The numerical results were subsequently validated using the Rayleigh method. The results indicate that the lowest natural frequencies were obtained in Mode 1 (14.475 Hz) and Mode 2 (14.480 Hz). Based on the EMPF evaluation, five dominant vibration modes (Modes 1, 2, 6, 7, and 8) were identified as having significant mass participation and collectively representing the dynamic characteristics of the crane mast through the required CEMPF criterion. The frequency separation assessment showed that Modes 1 and 2 have the potential to experience resonance, whereas Modes 6, 7, and 8 satisfy the acceptance criteria specified by BV Rules 2025 and ABS Rules 2022. Furthermore, validation using the Rayleigh method yielded a difference of 8.99% compared with the FEM results, indicating that the numerical model provides a reliable representation of the dynamic behavior of the ship crane mast.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Analisis Modal, Effective Mass Participation Factor (EMPF), Frekuensi Alami, Metode Elemen Hingga, Struktur Tiang Crane Kapal, Modal Analysis, Effective Mass Participation Factor (EMPF), Natural Frequency, Finite Element Method, Ship Crane Mast.
Subjects:	T Technology > TJ Mechanical engineering and machinery > TJ1363 Cranes, derricks, etc. V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM156 Naval architecture V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM731 Marine Engines
Divisions:	Faculty of Marine Technology (MARTECH) > Naval Architecture and Shipbuilding Engineering > 36201-(S1) Undergraduate Thesis
Depositing User:	Putra Dame Lamtua Saragi
Date Deposited:	03 Aug 2026 10:21
Last Modified:	03 Aug 2026 10:21
URI:	http://repository.its.ac.id/id/eprint/140768

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