Alat Kejuruteraan Percuma
Kalkulator Frekuensi Semula Jadi
Kira frekuensi semula jadi bagi sistem spring jisim. Masukkan kekakuan jisim dan spring untuk mendapatkan frekuensi dalam Hz, frekuensi sudut, tempoh, RPM setara dan pesongan statik.
Keputusan
Frekuensi Semula Jadi Sistem Spring Jisim
Frekuensi semula jadi bagi sistem spring jisim darjah kebebasan tunggal tanpa redam:
- k — kekakuan spring (N/m). Jika diberikan dalam N/mm, darabkan dengan 1000.
- m - jisim (kg)
Frekuensi Sudut
Tempoh dan Pesongan Statik
Di mana g = 9.81 m/s² dan k adalah dalam N/mm untuk hasil pesongan dalam mm.
Contoh Praktikal
Diberi: Jisim mesin = 150 kg, Jumlah kekakuan spring k = 300 N/mm
k dalam N/m = 300 × 1000 = 300,000 N/m
f_n = (1/2π) × √(300,000/150) = (1/6.2832) × 44.72 = 7.12 Hz
ω_n = 2π × 7.12 = 44.7 rad/s
T = 1/7.12 = 0.140 saat
RPM Setara = 7.12 × 60 = 427 RPM
δ_statik = 150 × 9.81 / 300,000 × 1000 = 4.9 mm
⚠️ Nota: Pastikan kelajuan operasi sekurang-kurangnya 20–30% jauh dari frekuensi semula jadi untuk mengelakkan resonans. Jika beroperasi berhampiran resonans, tambahkan redaman atau ubah suai kekakuan/jisim.
Natural frequency is the frequency at which a system oscillates freely after being displaced from its equilibrium position and released. For a mass-spring system, it depends only on the mass and the spring stiffness.
Every mechanical structure has one or more natural frequencies, and they are fundamental properties used in vibration analysis, structural design, and machine diagnostics.
Knowing the natural frequency of a machine or its components is critical because if the operating speed (excitation frequency) coincides with the natural frequency, resonance occurs.
Resonance causes dramatically amplified vibrations that can lead to excessive wear, fatigue failure, bearing damage, and even catastrophic structural collapse. Engineers design machines so that operating speeds are well separated from natural frequencies.
Spring stiffness (rate) can be measured by applying a known force to the spring and measuring the resulting deflection. Stiffness k = Force / Deflection.
For example, if a 100 N force compresses a spring by 2 mm, the stiffness is 100/2 = 50 N/mm. You can also use a compression testing machine for accurate results, or consult the manufacturer's datasheet for the spring rate specification.
When the operating speed (excitation frequency) matches the natural frequency of the system, resonance occurs. At resonance, vibration amplitudes increase dramatically — theoretically to infinity in an undamped system, and to very high levels in real (lightly damped) systems.
This can cause rapid fatigue failure, excessive noise, bearing damage, and structural collapse. This is why vibration analysis always checks for proximity to resonance.
There are several strategies to avoid resonance:
- Change the operating speed so it is at least 20–30% away from any natural frequency
- Modify the stiffness by adding braces, stiffeners, or changing spring rates
- Change the mass of the vibrating component
- Add damping using vibration dampers, rubber isolators, or tuned mass dampers
- Use variable-speed drives to avoid dwelling at critical speeds during startup or shutdown
Prosedur yang diterangkan pada halaman ini telah dibangunkan dan diuji di lapangan oleh pasukan Vibromera menggunakan Balanset-1A, iaitu pengimbang dua saluran mudah alih dan penganalisis getaran untuk pengimbangan rotor di tapak.
Pengimbang mudah alih profesional, penganalisis getaran dan sistem pemantauan keadaan yang digunakan di lebih 50 buah negara. Kenal pasti masalah resonans dan imbang rotor di lokasi.
Nikolai Shelkovenko
Nikolai Shelkovenko ialah jurutera analisis getaran serta pengasas dan Ketua Pegawai Eksekutif (CEO) Vibromera. Selama lebih 15 tahun, beliau telah mengimbangi peralatan berputar terus di lapangan berbanding di bangku ujian: mulcher, kipas industri, penghancur, sentrifug, aci dan gelendong. Kerja inilah yang menjadi asal usul instrumen Balanset — ia direka sebagai alat yang boleh dibawa oleh pakar terus ke mesin dan digunakan bersendirian, di tapak, bukan sebagai peralatan makmal. Vibromera diasaskan pada 2017 dan telah berpangkalan di Porto, Portugal, sejak 2023. Pembangunan, pemasangan dan sokongan siri Balanset semuanya dijalankan di sini. Instrumen unggulan kami ialah Balanset-1A, penganalisis mudah alih untuk pengimbangan satu dan dua satah serta diagnostik getaran. Nikolai terlibat secara peribadi dalam sokongan pelanggan, menyelesaikan kes pengimbangan yang sukar, dan dalam pembangunan perisian. Beliau bekerja dengan pelanggan di seluruh dunia, dalam apa jua bahasa.
