Acoustic, shock, and coupled acoustic-structural analysis

Analyses performed using acoustic elements, an acoustic medium, and a dynamic procedure can simulate a variety of engineering phenomena including low-amplitude wave phenomena involving fluids such as air and water and “shock” analysis involving higher amplitude waves in fluids interacting with structures.

An acoustic analysis:

  • is used to model sound propagation, emission, and radiation problems;

  • can include incident wave loading to model effects such as underwater explosion (UNDEX) on structures interacting with fluids, airborne blast loading on structures, or sound waves impinging on a structure;

  • in Abaqus/Explicit can include fluid undergoing cavitation when the absolute pressure drops to a limit value;

  • is performed using one of the dynamic analysis procedures (About dynamic analysis procedures);

  • can be used to model an acoustic medium alone, as in the study of the natural frequencies of vibration of a cavity containing an acoustic fluid;

  • can be used to model a coupled acoustic-structural system, as in the study of the noise level in a vehicle;

  • can be used to model the sound transmitted through a coupled acoustic-structural system;

  • requires the use of acoustic elements and, for coupled acoustic-structural analysis, a surface-based interaction using a tie constraint or, in Abaqus/Standard, acoustic interface elements;

  • can be used to obtain the scattered wave solution directly under incident wave loading when the mechanical behavior of the fluid is linear;

  • can be used to obtain a total wave solution (sum of the incident and the scattered waves) by selecting the total wave formulation, particularly when nonlinear fluid behavior such as cavitation is present in the acoustic medium;

  • can be used to model problems where the acoustic medium interacts with a structure subjected to large static deformation;

  • in Abaqus/Standard can be used with symmetric model generation (Symmetric model generation) and symmetric results transfer (Transferring results from a symmetric mesh or a partial three-dimensional mesh to a full three-dimensional mesh);

  • in Abaqus/Standard can be used with steady-state transport (Steady-state transport analysis) and an acoustic flow velocity (*ACOUSTIC FLOW VELOCITY) to model acoustic perturbations of a moving fluid;

  • in Abaqus/Standard can include a coupled structural-acoustic substructure that was previously defined (Generating substructures);

  • can be used to model both interior problems, where a structure surrounds one or more acoustic cavities, and exterior problems, where a structure is located in a fluid medium extending to infinity; and

  • is applicable to any vibration or dynamic problem in a medium where the effects of shear stress are negligible.

A shock analysis:

  • is used to model blast effects on structures;

  • often requires double precision to avoid roundoff error when Abaqus/Explicit is used;

  • may include acoustic elements to model the effects of fluid inertia and compressibility;

  • may include virtual mass effects to model the effect of an incompressible fluid interacting with a pipe structure;

  • is performed using one of the dynamic analysis procedures (About dynamic analysis procedures);

  • can be used to model both interior problems, where a structure surrounds one or more fluid cavities, and exterior problems, where a structure is located in a fluid medium extending to infinity; and

  • in Abaqus/Explicit can include air blast loading on structures using the CONWEP model.

The following topics are discussed:

Related Topics
About ALE adaptive meshing
Steady-state transport analysis
In Other Guides
Acoustic medium
Acoustic and shock loads
Initial conditions in Abaqus/Standard and Abaqus/Explicit
*ACOUSTIC FLOW VELOCITY
*ACOUSTIC WAVE FORMULATION
*ADAPTIVE MESH
*BEAM FLUID INERTIA
*CONWEP CHARGE PROPERTY
*IMPEDANCE
*IMPEDANCE PROPERTY
*INCIDENT WAVE
*INCIDENT WAVE INTERACTION
*INITIAL CONDITIONS
*SIMPEDANCE
*TIE
Defining an acoustic pressure boundary condition
Creating the submodel boundary condition

ProductsAbaqus/StandardAbaqus/ExplicitAbaqus/CAE