Sound pressure level attenuation provided by thin rigid screens coupled to tall buildings

This paper computes the sound pressure attenuation provided by thin rigid screens placed on the walls of a tall building to protect the building from the direct sound incidence produced by sound pressure sources placed in its vicinity. The problem is formulated in the frequency domain via the Traction Boundary Element Method (TBEM), which overcomes the thin-body difficulty arising with the classical Boundary Element Method (BEM) formulation. The building, the screens and the ground are assumed to be infinitely long and rigid. The Green's functions used in the TBEM formulation allow the solution to be obtained without discretizing the flat solid ground and vertical solid facade. Thus, only the boundary of each rigid screen is modelled, which allows the TBEM to be efficient even at high excitation frequencies. The hypersingular integrals that result from the implementation of the TBEM are computed analytically. The algorithm is verified using a BEM model, which incorporates the Green's functions for a full space, thus requiring the full discretization of the domain. The model developed is then used to simulate wave propagation in the vicinity of thin rigid screens with different dimensions and geometries. The two-dimensional (2D) and three-dimensional (3D) time and frequency responses and sound pressure attenuation results are both computed over grids of receivers placed perpendicular and parallel to the building wall.

[1]  Eduardo Kausel,et al.  Frequency Domain Analysis of Undamped Systems , 1992 .

[2]  Vladimir Sladek,et al.  A boundary integral equation method for dynamic crack problems , 1987 .

[3]  John A. Hudson,et al.  Numerical modelling of seismic waves scattered by hydrofractures: application of the indirect boundary element method , 1998 .

[4]  T. Cruse.  Boundary Element Analysis in Computational Fracture Mechanics , 1988 .

[5]  António Tadeu,et al.  3D sound scattering by rigid barriers in the vicinity of tall buildings , 2001 .

[6]  T. Terai.  On calculation of sound fields around three dimensional objects by integral equation methods , 1980 .

[7]  D. Duhamel,et al.  SOUND PROPAGATION OVER NOISE BARRIERS WITH ABSORBING GROUND , 1998 .

[8]  Simon N. Chandler-Wilde,et al.  INFLUENCE OF SHAPE AND ABSORBING SURFACE—A NUMERICAL STUDY OF RAILWAY NOISE BARRIERS , 1998 .

[9]  David Prosper.  Modeling and detection of delaminations in laminated plates , 2001 .

[10]  J. Sládek,et al.  Transient elastodynamic three-dimensional problems in cracked bodies , 1984 .

[11]  António Tadeu,et al.  ACOUSTIC INSERTION LOSS PROVIDED BY RIGID ACOUSTIC BARRIERS OF DIFFERENT SHAPES , 2003 .

[12]  D. Duhamel.  EFFICIENT CALCULATION OF THE THREE-DIMENSIONAL SOUND PRESSURE FIELD AROUND A NOISE BARRIER , 1996 .

[13]  C. L. Morfey.  Dictionary of Acoustics , 2000 .

[14]  Luiz C. Wrobel,et al.  A DUAL BOUNDARY ELEMENT FORMULATION FOR SOUND PROPAGATION AROUND BARRIERS OVER AN IMPEDANCE PLANE , 1997 .

[15]  K. R. Fyfe,et al.  A study of 2D and 3D barrier insertion loss using improved diffraction-based methods , 1998 .

[16]  Y. Kawai,et al.  The application of integral equation methods to the calculation of sound attenuation by barriers , 1990 .

[17]  Yiu W. Lam,et al.  Using Maekawa's chart to calculate finite length barrier insertion loss , 1994 .

[18]  António Tadeu,et al.  Scattering of acoustic waves by movable lightweight elastic screens , 2003 .

[19]  P. Jean,et al.  THE IMPORTANCE OF SOURCE TYPE ON THE ASSESSMENT OF NOISE BARRIERS , 1999 .

[20]  Istvn L. Vr,et al.  Noise and Vibration Control Engineering , 2005 .

[21]  Massimo Guiggiani,et al.  Formulation and numerical treatment of boundary integral equations with hypersingular kernels , 1998 .

[22]  António Tadeu,et al.  Sound propagation around rigid barriers laterally confined by tall buildings , 2002 .

[23]  Luiz C. Wrobel,et al.  A novel boundary integral formulation for three-dimensional analysis of thin acoustic barriers over an impedance plane , 1998 .