Shells Of Complex Geometry Research Articles

Behavior of Polygonal Shells of Complex Geometry, Taking into Account the History of a High Level of Loading

The paper presents the results of the study of the stress-strain state of polygonal shells of positive and negative curvature with different geometric shape of the plan, taking into account the influence of the prehistory of a high loading level. To derive the resolving equation, equation, a mixed-type equation of the moment theory of shells was used. The calculation of the investigated out according to the moment theory, taking into account the influence of a complex stress state edge effect. The numerical implementation of this solution is carried out in relation to hinged and restrained shells. The bearing capacity of short-term and long-term loaded reinforced concrete polygonal shells was investigated by the method of limiting equilibrium.

Seismic Resistance of Nonlinearly Deformable Large-Span Spatial Structures, Taking into Account Changing Dynamic Stiffness

Elaboration analytical and computer modeling, changing dynamic parameters of short-term and long-term loaded nonlinearly deformable large-span spatial shell structures are investigated in this research paper. The proposed physical and geometrically nonlinear models of deformation and computational algorithms for solving dynamic problems are applied to assess the stress-strain state of smooth and ribbed spatial systems with variable stiffness caused by the accumulation of damage and the orthotropic structure reinforced by the ribs of the structures of the studied systems. The possibility of using the proposed method of accounting for variable dynamic stiffnesses in calculations for solving problems of dynamic strength and stability of spatial large-span shells of complex geometry is shown.

Helicoids 3D modeling for additive technologies

The article provides an analysis of modern and affordable software systems for modelling shells of complex geometry and the possibilities of using these software systems in 3D printing. Such an analysis made it possible to choose software systems that most accurately allow for the implementation of the 3D modeling method proposed in the article with subsequent printing on a 3D printer. This method is considered in detail on the example of constructing several types of helicoids. The process of 3D modeling of a helicoid is described step by step and is divided into several stages: parametric modeling of a helicoid in SCAD, editing of the resulting model in AutoCAD and its export to a special format for 3D printing. The use of the method of parametric modeling is due to its accuracy and uncompromisingness. With its help, one can accurately judge the type of the built surface. Parametric modeling is the construction of a surface by compiling equations on each axis, i.e. along the x, y, z axes, and for each type of surface there are specific characteristic equations. It is not possible to implement the method of parametric modeling in all software systems; in this connection, certain difficulties arise. The article analyzes the difficulties encountered in 3D modeling of the helicoid and suggests ways to solve them.

Una mirada a medio siglo de cimentaciones laminares, métodos de cálculo e investigaciones asociadas en Cuba

The work shows a summary of the most significant shells foundations built in Cuba in the last decades and the developments related to these in term of methods of calculation of plates and shells of complex geometry using reference surfaces and reference bodies, from the generalization of the projected solicitations method (Pucher, 1934) with the use of referential surfaces (Hernandez, 1970) and other developments made in the mechanics of deformable solid by the Method of Duality (Rianitsiyn, 1974; Castaneda, 1993) and the Static-Geometric Analogy in the mechanics of the deformable solid (Castaneda, 1985).It also includes a summary of the research developed in recent years on the stress-strain states of soil under and inside shell foundations for chimneys of 74.5 m in sugar industries (Cobelo, 2004), comparative studies made of these with the use of the FEM (Gonzalez, 2010) and other research projects currently running (Alvarez, 2010 ).

Nonlinear two-dimensional static problems for thin shells with reinforced curvilinear holes

Results on stress concentration in thin shells with curvilinear holes subject to plastic deformation and finite deflections are reviewed. The holes (circular, elliptical) are reinforced with thin-walled elements (rings, rods) of different stiffness. A numerical method of solving doubly nonlinear problems of statics for shells of complex geometry is outlined. The stress distribution near curvilinear holes in spherical, cylindrical, and conical shells under statical loading is studied. The numerical results are analyzed

SOME APPROACHES TO THE SOLUTION OF PROBLEMS ON THIN SHELLS WITH VARIABLE GEOMETRICAL AND MECHANICAL PARAMETERS

A number of approaches to the solution of stress problems for anisotropic inhomogeneous shells in the classical formulation are discussed. A review is made of approaches to the solution of one- and two-dimensional static problems for thin shells with variable parameters and to the solution of stress–strain problems for anisotropic shells of revolution under axisymmetric and non-axisymmetric loading, shallow convexo-convex shells, noncircular cylindrical shells, plates of various shapes, and shells of complex geometry

Free oscillations of shells of complex geometry with finite shear stiffness

By applying isoparametric approximations we develop a finite-element method for studying the oscillations of shells whose middle surfaces are Monge surfaces. As the starting point we take the model of shells of Timoshenko type. To solve the eigenvalue problem we apply the method of iterations in a subspace. Two figures. Five tables. Bibliography: 14 titles.

Numerical solution of boundary-value problems of the mechanics of shells of complex geometry with the use of general coordinate systems

Numerical solution of boundary-value problems of the mechanics of shells of complex geometry with the use of general coordinate systems

Computation of the thermoelastic deformation of three-dimensional pipeline components of complex shape

An approach to calculation of the stress-strain state of curved three-dimensional segments of pipelines under a temperature-force load, which is based on the use of effective algorithms for solution of two-dimensional edge problems of the theory of shells of complex geometry, is presented. A spiral loop of a circular pipeline is examined. Parameters are developed for the median surface and the results of a specific calculation are presented.

Numerical study of the stress-strain state of one- and three-layer plates and shells of complex geometry

Numerical study of the stress-strain state of one- and three-layer plates and shells of complex geometry