Research on sound insulation performance and noise reduction optimization of composite laminated cylindrical shells in the low and middle-frequency bands

ABSTRACT A composite laminated cylindrical shell noise experimental device is constructed to address sound insulation issues in low and middle-frequency bands. The composite cylindrical shell's sound insulation performance is tested within the 100–1000 Hz frequency range, obtaining the cavity's noise spectrum. The LMS Virtual.Lab Acoustic software for simulation is utilized to generate a corresponding finite-element model, which is subsequently verified by comparing it to the experimental data to ensure its accuracy. The study investigates the impact of composite fiber type, layer angle and material thickness on the acoustic insulation properties of a cylindrical shell. Additionally, the genetic algorithm is used to optimize the layer angle of the composite laminated cylinder shell. The results suggest that the insulation efficiency of the composite cylindrical shell improves as the fiber's modulus of elasticity and the material's thickness increase throughout the frequency ranging from 100 to 1000 Hz. The impact of the layer angle of the composite material on the sound transmission loss varies with the frequency. Furthermore, optimizing the layer angle of the fiber employing a genetic algorithm dramatically improves the sound insulation performance within the specified frequency range of 400–1000 Hz.