in recent year, the evolutionary structural optimization (eso) method, has been applied as an effective tool for structures design. the concept of eso method is to use the finite element  results in each iteration of process and removal of inefficient material based on these results. in this method there are several experimental parameters such as rejection rate and evolutionary rate that are e...

If little is known about the sample under test, ascertaining a quantitative material true stress–true strain relationship from a small punch test is not direct. Conventional inverse simulation methods have used experimental force–displacement curves that ignore the deformation shape of the punched sample. We present small punch test methodology and results that used experimental deformation sha...

We prove that the Schützenberger graph of any element of the HNN-extension of a finite inverse semigroup S with respect to its standard presentation is a context-free graph in the sense of [11], showing that the language L recognized by this automaton is context-free. Finally we explicitly construct the grammar generating L, and from this fact we show that the word problem for an HNN-extension ...

Displacement finite element models of various beam theories have been developed traditionally using conventional finite element basis functions (i.e., cubic Hermite, equi-spaced Lagrange interpolation functions, or spectral/hp Legendre functions). Various finite element models of beams differ from each other in the choice of the interpolation functions used for the transverse deflection w, tota...

QUADRATIC INVERSE EIGENVALUE PROBLEMS: THEORY, METHODS, AND APPLICATIONS Vadim Olegovich Sokolov, Ph.D. Department of Mathematical Sciences Northern Illinois University, 2008 Biswa Nath Datta, Director This dissertation is devoted to the study of quadratic inverse eigenvalue problems from theoretical, computational and applications points of view. Special attention is given to two important pra...

Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grain boundary deformation of nanocrystalline materials. The model consist of several crystalline cores with different orientations...

We consider a coefficient inverse problems for the Maxwell’ system in 3-D. The coefficient of interest is the dielectric permittivity function. Only backscattering single measurement data are used. The problem is formulated as an optimization problem. The key idea is to use the adaptive finite element method for the solution. Both analytical and numerical results are presented. Similar ideas fo...

This paper studies a regularization approach for an inverse problem of estimating a spatially-and-temporally dependent Robin coefficient arising in the analysis of convective heat transfer. The parameter-to-state map is analyzed, especially a differentiability result is established. A regularization approach is proposed, and the properties, e.g., existence and optimality system, of the function...