Pengukuran Stiffness Dan Frekuensi Natural Untuk Menilai Resiko Resonansi Pada Pondasi Mesin Induk

This research discusses the vibration phenomena on the main engine foundation. Mathematic modelling was developed to describe the vibration characteristics. The stiffness component of the main engine foundation is calculated using the combination method of spring, which considers the longitudinal and transversal foundation construction model. The stiffness of the main engine foundation is 2.09 x 108 N/m and the natural frequency is 16.076 Hz. No resonance occurs in the main engine foundation for the engine speed of 240 RPM, 310 RPM, 347 RPM, 360 RPM, 459 RPM (excitation frequency is 3,99 Hz , 5,16 Hz, 5,78 Hz, 5,99 Hz, 764 Hz). The value of natural frequency at specified engine rotation will be beneficial information for the ship crew to minimize the possibility of resonance occurring in the engine room.