The article deals with the peculiarities of the results of tests carried out to determine the characteristics of the contact zone organized by stamping on a steel plate. During the test, the specimen was in the steel mold in which it was manufactured. The steel form was used to prohibit horizontal movement of the steel thin plates and minimize the effect of uneven slippage of the steel gouge in the direction perpendicular to the shear force. The considered tests were carried out according to a specially developed methodology, which took into account the specifics of the contact zone shear operation, the applied tooling and took into account the set objectives of the study.

Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite design

We have considered the improvement of analytical formulas for the determination of bending moments in a single-span beam with semi-rigid nodes. We have obtained analytical relationships for deflections, angles of rotation, bending moments and shear forces in a single-span beam with semi-rigid nodes. A convenient coefficient from 0 to 1 is used to specify the intermediate stiffness node. The coefficient characterizes the fraction of possible rotation of the support node. When we derived the formulas, we used the assumption of constant bending stiffness of the beam along its length and linear deformation of the beam material under load. We did not consider the cases of loading the beam with concentrated forces and concentrated bending moments in the span. We realize the complexity and necessity of calculating beams with semi-rigid nodes, so we have created a table for easy calculation. In the table you will find the values of the supporting moments depending on the degree of possible angle rotation. With the information about the bearing moments, you can load the hinged beam with them and construct a bending moment diagram. The upper left and lower left values from the table are used to determine the bending moments at the supports. The upper right and lower right values of the table are used to determine the bending moments in the beam span.

Keywords: semi-rigid nodes, multilayer structures, calculation methods, contact zone, wooden beams, reinforcement, wood, reinforcement, environmental friendliness

The article deals with the peculiarities of the study objectives and test methodology for characterization of different contact zones organized in different ways and requiring different methodological approach for specimen fabrication and testing. The steel plate-concrete contact zone organized by stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone between the steel plate and the concrete, organized by the stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone of two wooden bars organized by epoxy glue with reinforcing fabric placed between the layers of glue is tested for shear without organizing the prohibition of horizontal movement. The contact zone formed at the connection of a steel plate and incompletely gained strength concrete, with the association of steel bars has features of fixing the actual strength of the concrete part of the specimen. The considered methods have both a number of common features and differences, which are taken into account in the proposed methods of fabrication and testing.

Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite construction

The article deals with the improvement of structural solutions of steel reinforced concrete slabs with external reinforcement. The possibility of creating an orthotropic steel reinforced concrete slab on a profiled deck with a continuous or discrete puff located perpendicular to the direction of corrugations is determined. This kind of construction works in bending in two directions along the wave and across the wave. This will allow slabs to be supported on three and four sides, which will make it possible to redistribute the pressure on the supports and reduce the stress concentration at the joints between the slab and the support structure. A continuous puff is assumed to have the same cross-section along its entire length, while a discrete puff can have a variable thickness. Two variants of the calculation of this structure are found, as a monolithic rod with a sprengel chain and as a composite rod with an explicit contact zone. When the stiffness of the contact zone is close to absolute, the rod can be considered as a monolithic rod. An experimental study of the characteristics of the contact zone of the profiled deck organised by means of stamping on the inner side of the corrugation is required, taking into account the perpendicular location of the corrugations to the span of the beam and the concrete part of the section. A comparative analysis of the existing techniques has been made and further experimental investigation methodology has been determined. A numerical evaluation of stresses in a steel plate has been carried out.

Keywords: steel reinforced concrete slabs, orthotropic slabs, calculation methods, contact zone, stamping