Analisis Critical Speed pada Poros Akibat Crack Menggunakan Metode Teoritis dan Metode FEA (Finite Element Analysis)
DOI:
https://doi.org/10.32493/jtc.v8i2.54973Keywords:
Poros, Retak, Frekuensi Alami, FEAAbstract
Poros merupakan komponen penting dalam sistem transmisi daya yang berputar dengan kecepatan tinggi dan mengalami beban berulang. Retakan pada poros mengurangi kekakuan, menurunkan frekuensi alami, dan menurunkan kecepatan kritis, yang meningkatkan risiko resonansi dan kegagalan dini. Studi ini menganalisis pengaruh variasi diameter poros (20 mm, 25 mm, 30 mm) dan kedalaman retak (2 mm, 4 mm, 6 mm) terhadap kecepatan kritis. Metode ini menggabungkan perhitungan teoretis menggunakan persamaan Euler–Bernoulli dengan Analisis Elemen Hingga (FEA) melalui Solidworks dan Ansys. Hasil menunjukkan bahwa retakan yang lebih dalam secara signifikan menurunkan kecepatan kritis. Misalnya, poros 20 mm tanpa retak memiliki kecepatan kritis mode 1 sebesar 5.638 rpm, yang turun menjadi 4.900 rpm dengan retakan 6 mm. Sebaliknya, poros 30 mm tanpa retak mencapai 8.458 rpm, menunjukkan resistansi yang lebih tinggi terhadap pengurangan frekuensi. Hasil teoretis dan simulasi menunjukkan tren yang serupa, yang menyoroti pentingnya deteksi retakan dini untuk memastikan operasi yang aman.
Abstract: Shafts are essential components in power transmission systems that rotate at high speeds and are subjected to repetitive loads. Cracks in shafts reduce stiffness, lower natural frequency, and decrease critical speed, which increases the risk of resonance and premature failure. This study analyzes the influence of shaft diameter variations (20 mm, 25 mm, 30 mm) and crack depths (2 mm, 4 mm, 6 mm) on critical speed. The method combines theoretical calculations using the Euler–Bernoulli equation with Finite Element Analysis (FEA) through Solidworks and Ansys. Results indicate that deeper cracks significantly lower critical speed. For instance, a 20 mm shaft without a crack has a mode 1 critical speed of 5,638 rpm, which drops to 4,900 rpm with a 6 mm crack. Conversely, a 30 mm shaft without crack reaches 8,458 rpm, showing higher resistance to frequency reduction. Theoretical and simulation results show similar trends, highlighting the importance of early crack detection to ensure safe operation.
Keywords: Shaft, Crack, Natural Frequency, FEA.
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