Valerii Sokov
@nuos.edu.ua
Scopus Publications
Scopus Publications
Valerii Sokov, Leontii Korostylov, Oleksandr Shchedrolosiev, Hryhorii Sharun, and Serhii Klymenkov
Private Company Technology Center
This paper considers a thin-walled steel beam-wall with broken edges, which is part of many structures. The wall of this beam consists of two prismatic parts with a straight transition from a lower wall height to a higher one, forming a broken upper edge together with the edges of the prismatic parts. The bottom straight edge of the wall is attached to the cladding. The beam-wall is affected by static and cyclic nominal loads, which can cause the appearance of elastic-plastic deformations in the stress concentrator. This causes non-fulfillment of static strength and the appearance and growth of fatigue cracks. In the current work, procedures of design and verification calculation of a steel beam-wall with fractured edges at elastic static and cyclic elastic-plastic deformation in the stress concentrator are proposed. The material of the beam is ideal elastic-plastic. Features of the procedures are the possibility of optimal design under conditions of elastic and elastic-plastic deformation, using dependences only for optimal elastic design. A distinctive signature of the procedures is that, through Neiber's formula, elastic-plastic characteristics are not determined by known elastic ones, as usual, but vice versa. According to the established dependences for cyclic elastic-plastic deformations in the concentrator, the theoretical concentration coefficient is determined, which, in turn, is involved in determining the optimal geometric parameters. The procedures give reliable results with nominal symmetrical cyclic loads up to 0.6 of the yield strength. This is because Naber's formula always yields conservative results, causing excess strength. The procedures can be applied separately for stretching-compression and bending, and with their combined action
V. M. Sokov
Springer Science and Business Media LLC
Valerii Sokov and Leontii Korostylov
Private Company Technology Center
This paper reports the dependences that have been derived to determine the effective width of a free flange in a dangerous cross-section of the wide-flange hull girder with the breaking of the wall/edges/axis at elastic-plastic deformation depending on the applied load for a perfectly plastic material without strengthening. Currently, there are no systematic dependences to determine the effective width of the free flange of girders of this type, except for certain cases. The technique is suitable for use for both purely elastic and elastic-plastic deformation. To calculate the stressed-strained state (SSS), a finite-element method (FEM) was used to solve the three-dimensional problem from the elasticity and plasticity theory. It has been shown that the node is exposed to simple loading. The reported results were derived within the framework of the deformation theory of plasticity. The largest ratio of external load to the boundary of fluidity is 0.9. The estimation scheme takes into consideration the most unfavorable working conditions of the examined node when the safest data are acquired. The dependences were built for the theoretical coefficient of concentration in a dangerous cross-section, which is used in the proposed procedure to determine the moment of transition from the elastic stage of deformation to elastic-plastic. When determining the effective width, the complex work of the flange and its deplanation was taken into consideration by defining the SSS components in the median plane. The feasibility of the idea of designing the SSS components on the inclined plane of a free flange has been proven. In this case, there is practically a (quasi) flat stressed state, suitable for the application of classical methods to determine the effective width. The proposed technique simplifies the calculations of the strength of the examined girder.