Boundary Condition for the Acoustic Impedance of Lightweight Micro Perforated Panels and Membranes
نویسندگان
چکیده
Theories of the acoustic impedance of micro perforated panels and membranes for normally incident waves have been well developed for decades. These theories are mainly based on the assumption that the particle velocity at the boundary of the hole wall is equal to zero. This assumption is valid when the panel/membrane is massive and does not vibrate. This paper aims to investigate the effects of the panel/membrane vibration on the acoustic impedance of micro perforated structures. When the panel/membrane is lightweight and vibrates, the particle velocity at the boundary of the hole wall is assumed equal to the velocity of the panel/membrane vibration. Based on this alternate boundary condition a new expression for the acoustic impedance of micro perforated panels and membranes is developed. This expression may be used for the prediction of the sound absorption of lightweight micro perforated panels and membranes.
منابع مشابه
Acoustic impedance of micro perforated membranes: Velocity continuity condition at the perforation boundary.
The classic analytical model for the sound absorption of micro perforated materials is well developed and is based on a boundary condition where the velocity of the material is assumed to be zero, which is accurate when the material vibration is negligible. This paper develops an analytical model for finite-sized circular micro perforated membranes (MPMs) by applying a boundary condition such t...
متن کاملAcoustic properties of 3D printed bio-degradable micro-perforated panels made of Corkwood Fiber-Reinforced composites
Introduction: Micro perforated panel (MPP) absorbents promise the next generation of sound absorbers as they have significant advantages over other porous adsorbents. In this study, we will investigate the acoustic performance of MPP absorbents made of biodegradable polylactic acid composite reinforced with natural corkwood fibers (PLA/Corkwood) by 3D printing technology. Material and Methods:...
متن کاملStudy of the effect of shape on acoustic performance of micro perforated absorbent at low frequencies
Introduction: Micro-perforated absorbents are one of the structures that are widely used nowadays. The sound absorption mechanism is performed by viscous energy losses in the cavities on the plate. In this study, the acoustic properties of non-flat perforated panels in oblique angle was investigated in numerical method. Material and Methods: This paper examined the effect of the surface shape ...
متن کاملExperimental investigation of perforations interactions effects under high sound pressure levels
Most models for predicting the acoustic response of perforated panels are based on the assumption that there is no interaction between the holes. The common way of taking into account the perforates effects is the use of Fok's functions. The few papers that deal with these effects study the case of low sound pressure levels. This paper investigates the Holes Interaction Effects (HIE) of perfora...
متن کاملExperimental and Numerical Study of Perforated Steel Plate Shear Panels
Thin perforated Steel Plate Shear (SPS) Walls are among the most common types of energy dissipating systems. The applied holes reduce the shear strength of the plate and allow to decrease the profile size of the members at the boundary of the panel when these systems are used in the typical design of structures. On the other hand, the different fracture locations of these panels are visible whe...
متن کامل