Alexander Ya. Grigorenko – författare

This book presents various dynamic processes in non-uniform piezoceramic cylindrical and spherical bodies based on numerical methods. It discusses different variants of nonhomogeneous structural polarized piezoceramic materials in the shape of cylinders and spheres, and highlights the validation of the reliability of the results obtained by numerical calculations. The content is based on an outlined theory and methods of three-dimensional electroelasticity problems.

This book examines new approaches for the estimation of errors in approximate theories. Numerical and analytical methods in mechanics often require the establishment of a set of basic equations, and various approaches exist to create approximate theories from them. The problem is that nobody knows the boundaries of the estimation of errors in approximate theories.

This book presents new approaches to overcome this problem and to provide the reader with suitable methods for the relevant field, including a representation of different scientific schools and different countries. These new methods are helping to solve many problems not only in analytical Mechanics but also in Physics, Mathematics, and Civil Engineering.

This book contains previously classified information on the physical and chemical characteristics of metallic and composite materials used in the production of elements of special-purpose structures, and reveals the set of techniques and tools through which this information was obtained. It sets the foundations for the methodology of systematic automated identification of the special-purpose structures by their fragments.

The main topics are theoretical foundations and practical results of scanning electron microscopy in determining chemical composition, structure, surface topography and frequency characteristics (reflection and absorption coefficients of electromagnetic waves) of fragments of the structures made of both metal alloys and composite materials.

Applied aspects such as the parameters of electromagnetic radiation recommended for effective identification of special-purpose structures made of composite radiation absorbent materials and coatings; development of a scientifically based system for automated identification of the structures by their fragments.

The book is aimed at solving the problem to prevent uncontrolled or "gray" transfer of special-purpose products, technologies and materials of military or dual use by forming a scientifically based automatic identification system (by class and country of origin) of special-purpose products by their fragments, using scanning electron microscopy to determine their chemical composition, structure, surface topography, and frequency characteristics.

The book is useful to a wide range of specialists in the field of materials science, as well as specialists in the defense sector of industry.

This volume focuseson the relevant general theory and presents some first applications, namelythose based on classical shell theory. After a brief introduction, during whichthe history and state-of-the-art are discussed, the first chapterpresents the mechanics of anisotropic heterogeneous shells, covering allrelevant assumptions and the basic relations of 3D elasticity, classical andrefined shell models. The second chapter examines the numerical techniques thatare used, namely discrete orthogonalization, spline-collocation and Fourierseries, while the third highlights applications based on classical theory, inparticular, the stress-strain state of shallow shells, non-circular shells,shells of revolution, and free vibrations of conical shells. The book concludeswith a summary and an outlook bridging the gap to thesecond volume.

This brief book presents solutions of stress-strain problems for a wide class of anisotropic inhomogeneous shells obtained by the refined model. Studying these problems results in severe computational difficulties due to partial differential equations with variable coefficients resulting from the constitutive relations of the original model. To solve this problem the book uses spline-collocation and discrete-orthogonalization methods. It analyses the influence of geometrical and mechanical parameters, of various kinds of boundary conditions, and of the loading conditions on the distributions of stress and displacement fields in shallow, spherical, conical, and noncircular cylindrical shells. The dependence of the stress-strain pattern on shell thickness variations is studied. The authors solve the problem also for the case of the thickness varying in two directions. They study how a variation in shell thickness influences the stress-strain state and consider noncircular cylindrical shells with elliptical and corrugated sections are considered. The results obtained during numerous calculations support the efficiency of the discrete-orthogonalization approach proposed in the monograph for solving static problems for anisotropic inhomogeneous shells when using the refined model.