Keywords: composite material

Influence of dynamic loads on fatigue strength of steel beams reinforced with carbon fiber

https://doi.org/10.58224/2618-7183-2023-6-2-35-46
Abstract
The paper evaluates the strength and fatigue characteristics of reinforced damaged steel beams using composite materials – fiber reinforced polymers (FRP) using an analytical model using the ANSYS program. An approach to design based on the methodology of a constant fatigue schedule is considered; models of five steel beams reinforced with carbon fiber are constructed in the ANSYS program. The model was loaded with a symmetrically located concentrated load until destruction. Fa-tigue crack propagation curves have shown that carbon fiber plates restrain crack growth and increase durability. The results showed that carbon fiber reinforcement of steel beams increases the ultimate load and increases the plasticity of the beam.
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THE USE OF COMPOSITE MATERIALS IN RECONSTRUCTION OF FLOORS OF INDUSTRIAL BUILDINGS

https://doi.org/10.34031/2618-7183-2019-2-3-58-64
Abstract
The article discusses the relevance of the use of composite materials in the reconstruction of exposed to heavy loads of concrete and reinforced concrete floors of industrial buildings. It is noted that at the present stage of development of the construction industry special attention is paid to the use of steel fibreconcrete, as this material allows with minimal material and labor costs to carry out work on the reconstruction of industrial floors. The novelty of this study is the use as an adhesive between the existing floor, which is to be restored and strengthened, and the newly laid steel-fiber concrete layer of polymer-bitumen composite material with the addition of cement and graphite powder, previously obtained by the authors experimentally. This material with the required thickness is also a structural layer for leveling the surface of the lower layer, reducing friction under the sole of the upper steel-fiber concrete layer and the existing floor. The paper presents the technology of work in the reconstruction. The composition of the steel-fiber concrete layer is adopted on the basis of studies by other authors. Despite the fact that the experiments proved the solidity and strength of the reconstruction of the floor by the developed technology, the article notes that the final characteristics of the proposed floor design and technology can be identified only during operation, which can be the basis for further research on optimizing the thickness of the layers proposed for use of composite materials. For the evaluation of economic efficiency of application of these composite materials in the reconstruction of the concrete floors in the course of the experiment, there are revealed some figures for labor and material costs.
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