A 3-D BOUNDARY-ELEMENT FORMULATION OF VISCOELASTIC MEDIA WITH GRAVITY

This paper presents a boundary element formulation for 3-D linear and viscoelastic bodies subjected to the body force of gravity. The Laplac e transformation is first used to suppress the time variable, and solu tions of displacements and stresses are found in the transformed domai n. The time domain solutions are then found by an accurate and efficie nt numerical inversion method which requires only real calculations fo r all quantities. Input and output data, and solutions in the transfor med and time domains are connected through an Interactive Data Languag e code written by the authors. While particular solutions of stresses and displacements related to the body force of gravity (which is appli ed at time t = 0 and is kept constant) are derived, the Green's functi ons in the Laplace domain are obtained through the correspondence prin ciple. The new formulation has been implemented into an existing 3-D B EM program, and several numerical examples involving 3-D viscoelastic bodies are presented. Although the discussion in this paper focuses on Maxwell viscoelastic and isotropic media, other linear isotropic and even anisotropic viscoelastic models can also be incorporated, without difficulty, into the 3-D viscoelastic BEM program.