Stress-Strain State in the Zone of Load Transfer in a Composite Specimen under Uniaxial Tension

The stress-strain state in the zone of load transfer in a uniaxially stretched specimen made of a unidirectional epoxy carbon-fiber-reinforced plastic (CFRP) is investigated. A parametric analysis of the influence of geometric and mechanical characteristics of the specimen on its stress-strain state is performed by means of finite-element modeling. The parameters allowing us to significantly reduce the dangerous concentration of transverse and tangential stresses are revealed. The mechanical tensile characteristics of a high-strength pultruded unidirectional CFRP are determined experimentally, and the size effect of its strength is estimated.     

A refined stress-strain analysis in the load transfer zone of flat specimens of high-strength unidirectional composites in uniaxial tension 1. Theoretical analysis

With the use of an analytical approach developed, the influence of distribution of a tangential load on the stress concentration in uniaxially tensioned flat specimens of high-strength unidirectional composites near the grips of a testing machine is evaluated. In view of singularity of the analytical solution derived at the points of discontinuity of boundary conditions, for estimating the stress concentration, it is suggested to employ the averaged value of longitudinal stresses, which is calculated by means of an improper integral across the thickness of a near-surface layer. __________ Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 6, pp. 787–796, November–December, 2006.     

Associative rings

This survey is a continuation of a series of surveys on the theory of rings and modules. Results on the theory of associative rings covered in Referativnyi Zhurnal Matematika during the period 1972–1976 are discussed. The theory of radicals, rings with polynomial identities, rings of fractions, extensions of rings, group rings, properties of various classes of rings, topological and ordered rings, and other topics are considered.Translated from Itogi Nauki i Tekhniki, Algebra, Topologiya, Geometriya, Vol. 16, pp. 91–190, 1978.     

Completion of the group topology of a countable group

Kishinev. Translated from Sibirskii Matematicheskii Zhurnal, Vol. 31, No. 1, pp. 3–13, January–February, 1990.     

Completeness of maximal topological groups

Under the assumption of Booth's lemma a negative solution is obtained for Arnautov' s problem: is it true that each nondiscrete topology on a group can be strengthened to a discrete complete one?