Commercial3D reticular nickel foam and its composite structure were investigated on the sound absorption at200-2000Hz.The absorption performance of foam plates1?5layers(1-layer thickness:2.3mm;porosity:89%;average por...Commercial3D reticular nickel foam and its composite structure were investigated on the sound absorption at200-2000Hz.The absorption performance of foam plates1?5layers(1-layer thickness:2.3mm;porosity:89%;average pore-diameter:0.57mm)was found to be poor,and could be improved by adding backed cavum or front perforated thin sheet.The absorption coefficient could reach about0.4at1000-1600Hz for the composite structure of5-layer foam with a backed5mm-thick cavum,and even0.68at about1000Hz for that of2-layer foam with the same cavum and a perforated plate closely in front of the foam.展开更多
We present the design of micro-helix metamaterial supporting high sound absorption characteristic by 3D printing. The sample structure which is fabricated out of polylactide （PLA） material, many micro-helix are arra...We present the design of micro-helix metamaterial supporting high sound absorption characteristic by 3D printing. The sample structure which is fabricated out of polylactide （PLA） material, many micro-helix are arranged by periodic arrays on XY plane. Experiment measurement results show that different geometrical dimensions of helix vestibule and cavity depth have a great effect on sound absorption coefficient. Physical mechanism depends on the friction and viscosity between the air and the helix vestibule. This work shows great potential of micro-structure metamaterial in noise control applications require light weight and large rigid of sound absorption.展开更多
基金Project (C16) supported by the Testing Foundation of Beijing Normal University,China
文摘Commercial3D reticular nickel foam and its composite structure were investigated on the sound absorption at200-2000Hz.The absorption performance of foam plates1?5layers(1-layer thickness:2.3mm;porosity:89%;average pore-diameter:0.57mm)was found to be poor,and could be improved by adding backed cavum or front perforated thin sheet.The absorption coefficient could reach about0.4at1000-1600Hz for the composite structure of5-layer foam with a backed5mm-thick cavum,and even0.68at about1000Hz for that of2-layer foam with the same cavum and a perforated plate closely in front of the foam.
基金supported by the National Natural Science Foundation of China (11704314 and 11474230)the Fundamental Research Funds for the Central Universities (3102016QD056) for financial support
文摘We present the design of micro-helix metamaterial supporting high sound absorption characteristic by 3D printing. The sample structure which is fabricated out of polylactide （PLA） material, many micro-helix are arranged by periodic arrays on XY plane. Experiment measurement results show that different geometrical dimensions of helix vestibule and cavity depth have a great effect on sound absorption coefficient. Physical mechanism depends on the friction and viscosity between the air and the helix vestibule. This work shows great potential of micro-structure metamaterial in noise control applications require light weight and large rigid of sound absorption.
