V. N. Chekhov

The Three-Dimensional Theory of Stability of Fibrous and Laminated Materials

An analysis is made of the results of investigations into the internal and surface instability of fibrous and laminated composites within the framework of the piecewise-homogeneous model and the equations of the three-dimensional linearized theory of stability. The possible buckling modes of the reinforcing elements in composites with either an elastic (polymeric) or elastoplastic (metallic) matrix are studied. The reliability domains of applied approximate design models are determined and some applications of results on fracture (due to structural instability) of unidirectional composites are presented

Stability of an Elastic Layer Stack Between Two Half-Spaces Under Compressive Loads

A stability problem is solved for a multicomponent medium consisting of a layer stack and two structurally homogeneous half-spaces. The analysis is made within the framework of the piecewise-homogeneous model and the three-dimensional linearized theory of stability for small subcritical strains. The properties of isolated elements of the medium are determined within the framework of the orthotropic linearly elastic model. Specific numerical results are obtained for the case of plane strain

Investigations in the theory of thin shells with openings (review)

The quest ion of the invest igat ion of the deformat ion of thin shel ls with openings is v e r y t ime ly , since such shel ls a re used in p r e s e n t d a y technology as e l ements of c a r ry ing cons t ruc t ions . The p re sence of openings br ings about a sha rp change in the s t r e s s field in the shel l , which has a cons iderable effect on the c a r r y i n g capaci ty of the const ruct ion as a whole. In the genera l case , the use of the c l a s s i ca l theory of thin shel ls in the invest igat ion of such p r o b l e m s leads to the solution of d i f ferent ia l equations of a high o r d e r in pa r t i a l de r iva t ives for the region of the middle sur face of a shell of complex fo rm. In view of the difficulty of this kind of p rob l em and the absence of sufficiently powerful computing techniques, invest igat ions of the de te rmina t ion of the s t r e s s s t r a i n s ta te of thin shel ls with openings have been developed intensively only dur ing the course of the l as t two or th ree decades .

Stability of Laminated Coatings Under Elastoplastic Deformation

A piecewise-homogeneous-medium model is used to consider a stability problem for layered elastoplastic coatings under plain strain. The theory of small elastoplastic strains is used. Characteristic equations are derived in an explicit form for a power dependence between the strain and stress intensities. The effect of the inelastic properties of layers on the phenomenon being studied is demonstrated by a specific example

Surface Instability of Laminated Materials of Regular Structure Under Triaxial Compression

The surface instability of laminated composites of regular structure is analyzed in a three-dimensional linearized formulation. A case is considered where the material is compressed by a surface distributed dead or follower load. Numerical results are presented for a specific problem.

The Stability of Laminated Elastomer Coatings Under Surface Loading

The stability of laminated elastomer coatings at normal and high temperatures is considered in a three-dimensional formulation. The problem is formulated and the basic characteristic equations are derived. Graphs of the physicomechanical parameters of some elastomers against temperature are experimentally obtained. Specific examples for a three-layer coating are considered