The method of fundamental solutions for three-dimensional inverse geometric elasticity problems

We investigate the numerical reconstruction of smooth star-shaped voids (rigid inclusions and cavities) which are compactly contained in a three-dimensional isotropic linear elastic medium from a single set of Cauchy data (i.e. nondestructive boundary displacement and traction measurements) on the accessible outer boundary. This inverse geometric problem in three-dimensional elasticity is approximated using the method of fundamental solutions (MFS). The parameters describing the boundary of the unknown void, its centre, and the contraction and dilation factors employed for selecting the fictitious surfaces where the MFS sources are to be positioned, are taken as unknowns of the problem. In this way, the original inverse geometric problem is reduced to finding the minimum of a nonlinear least-squares functional that measures the difference between the given and computed data, penalized with respect to both the MFS constants and the derivative of the radial coordinates describing the position of the star-shaped void. The interior source points are anchored and move with the void during the iterative reconstruction procedure. The feasibility of this new method is illustrated in several numerical examples

The method of fundamental solutions for the solution of elliptic boundary value problems

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN019530 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Comparison of two methods for the computation of singular solutions in elliptic problems

AbstractWe compare two numerical methods for the solution of elliptic problems with boundary singularities. The first is the integrated singular basis function method (ISBFM), a finite-element method in which the solution is approximated by standard polynomial basis functions supplemented by the leading terms of the local (singular) solution expansion. A double application of Green's theorem reduces all Galerkin integrals containing singular terms to boundary integrals with nonsingular integrands. The originally essential boundary conditions are weakly enforced by means of Lagrange multipliers. The second method is a singular function boundary integral method which can be viewed as a modification of the ISBFM. The solution is approximated only by the leading terms of the local solution expansion. The discretized equations are boundary integrals and the dimension of the problem is reduced by one. The two methods are applied to the cracked-beam problem giving very accurate estimates of the leading singular coefficients. Comparisons are made and their limitations are discussed

Optimization analysis of innovative modular air-cooled condensers for CSP plants

In this work, a parametric optimization analysis of various innovative modular air-cooled condenser systems is carried out in order to identify the optimum system configuration and size to be used as the cooling system in a 50MWe parabolic trough concentrated solar power (CSP) plant. The optimization analysis is conducted individually on a total of 17 different configurations and on a total of 8 different condenser sizes for each configuration. The results identify the optimum air cooled condenser configuration and size that can achieve the minimum CSP plant electricity unit cost

Optimization analysis of innovative modular air-cooled condensers for CSP plants

In this work, a parametric optimization analysis of various innovative modular air-cooled condenser systems is carried out in order to identify the optimum system configuration and size to be used as the cooling system in a 50MWe parabolic trough concentrated solar power (CSP) plant. The optimization analysis is conducted individually on a total of 17 different configurations and on a total of 8 different condenser sizes for each configuration. The results identify the optimum air cooled condenser configuration and size that can achieve the minimum CSP plant electricity unit cost

Optimization analysis of innovative modular air-cooled condensers for CSP plants

In this work, a parametric optimization analysis of various innovative modular air-cooled condenser systems is carried out in order to identify the optimum system configuration and size to be used as the cooling system in a 50MWe parabolic trough concentrated solar power (CSP) plant. The optimization analysis is conducted individually on a total of 17 different configurations and on a total of 8 different condenser sizes for each configuration. The results identify the optimum air cooled condenser configuration and size that can achieve the minimum CSP plant electricity unit cost