J.A.F. Santiago¹, L.C. Wrobel²

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.3, pp. 73-80, 2000, DOI:10.3970/cmes.2000.001.375

Abstract This work presents a boundary element formulation for two-dimensional acoustic wave propagation in shallow water. It is assumed that the velocity of sound in water is constant, the free surface is horizontal, and the seabed is irregular. The boundary conditions of the problem are that the sea bottom is rigid and the free surface pressure is atmospheric.
For regions of constant depth, fundamental solutions in the form of infinite series can be employed in order to avoid the discretisation of both the free surface and bottom boundaries. When the seabed topography is irregular, it is More >

A.J. Yiotis¹, J.T. Katsikadelis¹

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.2, pp. 95-104, 2000, DOI:10.3970/cmes.2000.001.255

Abstract The Analog Equation Method is applied to the static and dynamic analysis of thin cylindrical shell panels. The Fl\"{u}gge theory is adopted. The three displacement components are established by solving two membrane and one plate bending problems under the same boundary conditions subjected to "appropriate'' (equivalent) fictitious loads. Numerical results are presented which illustrate the efficiency and the accuracy of the proposed method. More >

Wenjing Ye¹, Subrata Mukherjee²

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 111-120, 2000, DOI:10.3970/cmes.2000.001.111

Abstract Polynomial driving-force comb drives are designed using numerical simulation. The electrode shapes are obtained using the indirect boundary element method. Variable gap comb drives that produce combinations of linear, quadratic, and cubic driving-force profiles are synthesized. This inverse problem is solved by an optimization procedure. Sensitivity analysis is carried out by the direct differentiation approach (DDA) in order to compute design sensitivity coefficients (DSCs) of force profiles with respect to parameters that define the shapes of the fingers of a comb drive. The DSCs are then used to drive iterative optimization procedures. Designs of variable More >