Pendugaan Sifat Mekanis Batang Bambu Berdasarkan Pengujian Nondestruktif Berbasis Akustik di Lapangan

Abstract

Bambu merupakan bahan biomassa yang dapat digunakan sebagai bahan baku pengganti kayu. Pengujian sifat mekanis bambu menjadi penting untuk mengetahui kekuatan bambu sebagai bahan baku konstruksi. Penelitian ini bertujuan menganalisis karakteristik gelombang bunyi pada batang tanaman bambu dan batang bambu tebangan serta menduga sifat kekakuan lentur batang bambu. Metode yang digunakan yaitu metode nondestruktif berbasis akustik menggunakan alat Fakopp Microsecond Timer. Penelitian dilakukan terhadap 15 batang bambu betung (Dendrocalamus asper) dan 15 batang bambu tali (Gigantochloa apus). Hasil penelitian menunjukkan bahwa karakteristik gelombang bunyi dapat dipengaruhi oleh jenis bambu, kondisi batang bambu, posisi transduser, posisi titik pengujian dan posisi aksial dengan signifikansi p<0,05. Nilai rata-rata velocity bambu tali > bambu betung, nilai rata-rata velocity pada kondisi batang bambu tebangan > batang tanaman bambu, nilai rata-rata velocity posisi transduser sejajar > berlawanan, nilai rata-rata velocity Buku-Buku > Ruas-Ruas > Ruas-Buku dan nilai rata-rata velocity posisi aksial ujung > tengah > pangkal. Hasil analisis statistik menunjukkan nilai kecepatan gelombang bunyi dapat menduga nilai kekakuan lentur dengan koefisien determinasi sebesar R2 = 81,41%.

Bamboo is a biomass material that can be used as a substitute for wood. Testing the mechanical properties of bamboo is important to determine the strength of bamboo as a construction raw material. This study aims to analyze the sound wave characteristics of bamboo plant culms and felled bamboo culms and to estimate the flexural stiffness properties of bamboo culms. The method used is an acoustic-based nondestructive method using the Fakopp Microsecond Timer tool. Research was conducted on 15 betung bamboo culms (Dendrocalamus asper) and 15 tali bamboo culms (Gigantochloa apus). The results showed that the sound wave characteristics can be influenced by the type of bamboo, the condition of the bamboo culm, the position of the transducer, the position of the testing point and the axial position with a significance of p<0,05. The average velocity value of bamboo tali > bamboo betung, the average velocity value in the condition of felled bamboo stems > bamboo plant stems, the average velocity value of transducer positions parallel > opposite, the average velocity value of Node-Node > Internode-Internode > Internode-Node and the average velocity value of axial positions tip > center > base. The statistical analysis shows that the sound wave velocity value can predict the bending stiffness value with a coefficient determination R2 = 81,41%.