1. Oya, A., Kasahara, N., Horigome, R., Structure of porous carbon-fiber from phenolic polymer containing polystyrene microbeads, Journal of Materials Science Letters , Vol. 20, pp. 409-411, (2001).
2. Lukyanov, A., A., Effect of fiber orientation on the structure of shock waves in carbon fiber-epoxy composites, Mechanics of Composite Materials , Vol. 47, No. 6, pp. 617-626, (2012).
3. Stănescu, N., M., Bolcu, D., Pastramă, S., D., Ciucă, I., Manea, I., Baciu, F., Determination of damping factor, to vibrations of compositebars
The composite bars have become a useful substitute for conventional reinforcement in civil engineering structures for which load capacity and resistance to influences of environmental factors' are required. Considering the requirements of responsible design of engineering structures with particular emphasis on durability, the use of non-metallic reinforcement in reinforced structural elements allows to reduce the costs related to erection of buildings, as well as the costs of building maintenance and renovations. The behaviour of model beams made of concrete reinforced with composite bars (fiber reinforced polymer bars) in three-point bending test was analyzed. The strength parameters of composite bars were tested. The bending capacity, deformation of concrete, and beam deflection were determined. Crack propagation in the model beams under load was analyzed using the Aramis 5M optical measuring system. Due to the strength characteristics of the composite reinforcing bars, the beams exhibited significant tensile strains, which resulted in the development of cracks of considerable width.
The paper concerns the rheological bending problem of wooden beams reinforced with embedded composite bars. A theoretical model of the behaviour of a multi-layered beam is presented. The component materials of this beam are described with equations for the linear viscoelastic five-parameter rheological model. Two numerical analysis methods for the long-term response of wood structures are presented. The first method has been developed with SCILAB software. The second one has been developed with the finite element calculation software ABAQUS and user subroutine UMAT. Laboratory investigations were conducted on sample beams of natural dimensions in order to validate the proposed theoretical model and verify numerical simulations. Good agreement between experimental measurements and numerical results is observed.
Piotr Radziszewski, Wioletta Jackiewicz-Rek, Michał Sarnowski and Marek Urbański
Over the course of operation, asphalt road pavements are subjected to damage from car traffic loads and environmental factors. One of the possible methods of strengthening damaged asphalt pavements may be the application of an additional rigid layer in the form of a cement concrete slab with continuous reinforcement.
This paper presents a material-technological and structural solution for composite pavement where a cement concrete slab with continuous HFRP bar reinforcement is used for strengthening. Based on laboratory tests, the serviceability of composite bar reinforcement of rigid pavement slabs was shown. A design for strengthening asphalt pavement with a concrete slab with steel bar and corresponding HFRP bar reinforcement was developed. The composition of a pavement cement concrete mix was designed, and experimental sections were formed. Based on laboratory tests of samples collected from the surfaces of experimental sections and the diagnostic tests carried out in “in situ” conditions, the authors will try, in the nearest future (Part II: In situ observations and tests), to confirm the effectiveness of strengthening asphalt pavements with cement concrete slabs with HFRP components.
The most important piece of road infrastructure is bridges. Wooden bridges have advanced constantly during the past decades. The trend began in Scandinavian countries but has also now gained significant ground in Russia. This research studies experimental endurance potential of the joints of the wooden beam while considering the coefficient of asymmetry of the cycle, which corresponds to the actual operating conditions. Performance analysis of the composite bars is carried out based on the experiment; the development of a special methodology for calculating the joints of wooden elements with the dowel plates for their better endurance is also introduced in this paper. The results of experimental studies on the performance of bending composite wooden bridge bars based on dowel plates operating under cyclic influences thus determine the endurance limit of wood for composite wooden bridge beams based on dowel plates. The calculation technique and interdependence of the endurance coefficient affecting the asymmetry coefficient of the bent composite wooden bridge bars on the dowel plates under cyclic loading are considered. The experimental data on the endurance of composite wooden bridge beams have been obtained, and separate analysis has been made of the compounds under cyclic loading performance; a method has been developed for calculating the bent composite wooden bridge bars reinforced by the dowel plates under cyclic influences.
orthotropic panel subjected to a combined loading . – Advances in Materials Science and Engineering, vol.2013, Article ID 710143,13 pages.
Deb Nath S.K., Ahmed S.R. and Afsar A.M. (2006): Displacement potential solution of short stiffened flat compositebars under axial loading . – International Journal of Applied Mechanics and Engineering, vol.11, No.3, pp.557–575.
Deb Nath S.K., Afsar A.M. and Ahmed S.R. (2007): Displacement potential solution of a deep stiffened cantilever beam of orthotropic composite material . – Journal of Strain Analysis for Engineering