The preparation method of porous material based on additive manufacturing was studied

and the experimental study on the sound absorption characteristics of the material was carried out. Based on the additive manufacturing technology of fused deposition modeling (FDM)

a direct fifilling method which could quickly realize the geometric model of porous materials was constructed. The relationship between the process parameters and the structural parameters of porous materials was established. By setting the process parameters such as thickness of the printed part

fifilling form

fifilling rate

printing line width

printing layer height and layer angle

the key parameters such as thickness

pore structure form

porosity

bar size and angle of the porous materials can be effectively controlled

which avoids the tedious and detailed modeling process of a large number of microstructures. The sound absorption coefficient was measured by double microphone impedance tube. The effffects of thickness

bar size and pore structure of porous material on sound absorption performance were systematically studied. The results show that the porosity (bar spacing) has the most signifificant inflfluence on the sound absorption peak. When the porosity increases from 20% to 30%

the sound absorption peak increases from 0.8 to 0.98. When the porosity increases from 30% to 60%

the sound absorption peak decreases from 0.98 to 0.6. The most obvious inflfluence on the resonant frequency corresponding to the sound absorption peak is the material thickness. When the material thickness increases from 10 mm to 30 mm

the resonant frequency corresponding to the sound absorption peak decreases from 6000 Hz to 1750 Hz. The research work in this paper verififies the feasibility of using additive manufacturing to realize porous materials with accurate geometric characteristics

and opens up a broad way for the customization of porous materials to meet specifific sound absorption performance requirements.