In this paper, the peeling behavior and the spalling resistance effect of carbon fiber reinforced polymer （CFRP） sheets externally bonded to bent concrete surfaces are firstly investigated experimentally. Twenty one...
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In this paper, the peeling behavior and the spalling resistance effect of carbon fiber reinforced polymer （CFRP） sheets externally bonded to bent concrete surfaces are firstly investigated experimentally. Twenty one curved specimens and seven plane specimens are studied in the paper, in which curved specimens with bonded CFRP sheets can simulate the concrete spalling in tunnel, culvert, arch bridge etc., whereas plane specimens with bonded CFRP sheets can simulate the concrete spalling in beam bridge, slab.bridge and pedestrian bridge. Three kinds of curved specimens with different radii of curvature are chosen by referring to practical tunnel structures, and plane specimens are used for comparison with curved ones. A peeling load is applied on the FRP sheet by loading a circular steel tube placed into the central notch of beam to debond CFRP sheets from the bent concrete surface, meanwhile full-range load-deflection curves are recorded by a MTS 831.10 Elastomer Test System. Based on the experimental results, a theoretical analysis is also conducted for the specimens. Both theoretical and experimental results show that only two material parameters, the interfacial fracture energy of CFRP-concrete interface and the tensile stiffness of CFRP sheets, are needed for describing the interfacial spalling behavior. It is found that the radius of curvature has remarkable influence on peeling load-deflection curves. The test methods and test results given in the paper are helpful and availab.e for reference to the designer of tunnel strengthening.
Fiber reinforced polymer （FRP） composites are increasingly being used for the re-pair and strengthening of deteriorated concrete structural components through adhesive bonding of prefabricated strips/plates and the ...
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Fiber reinforced polymer （FRP） composites are increasingly being used for the re-pair and strengthening of deteriorated concrete structural components through adhesive bonding of prefabricated strips/plates and the wet lay-up of fabric. Interfacial bond failure modes have attracted the attention of researchers because of the importance. The objective of the present study is to analyse the interface failure mechanism of reinforced concrete continuous beam strength-ened by FRP. An analytical solution has been firstly presented to predict the entire debonding process of the model. The realistic bi-linear bond-slip interfacial law was adopted to study this problem. The crack propagation process of the loaded model was divided into four stages （elastic,elastic-softening,elastic-softening-debonded and softening-debonded stage）. Among them,elastic-softening-debonded stage has four sub-stages. The equations are solved by adding suitable stress and displacement boundary conditions. Finally,critical value of bond length is determined to make the failure mechanism in the paper effective by solving the simultaneously linear algebraic equations. The interaction between the upper and lower FRP plates can be neglected if axial stiffness ratio of the concrete-to-plate prism is large enough.
A vibration reduction system of viscoelastic dampers is introduced into Kewitte single-layer latticed spherical shell (D=60m). Through dynamic FE simulation, the stability of controlled shell and the correspondent unc...
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ISBN:
(纸本)9781846260612
A vibration reduction system of viscoelastic dampers is introduced into Kewitte single-layer latticed spherical shell (D=60m). Through dynamic FE simulation, the stability of controlled shell and the correspondent uncontrolled one is compared. The different vibration schemes with initial geometric imperfection under different earthquake loadings are especially investigated. The results show that Liapunov stability of controlled shell with viscoelastic dampers can be evidently improved when compared with the uncontrolled shell;the vibration reduction is more obvious when considering the initial geometric imperfection of the shell. The damper's parameters have great influence on the vibration control effort.
After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication *** hereby retract the content of this pa...
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ISBN:
(纸本)9781424449941
After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication *** hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this *** presenting author of this paper has the option to appeal this decision by contacting TPII@***.
In general, analytical solution for the scattering problem of SH plane wave by a cavity in half-space primarily focused on the circular structure case. However, the case for U-shaped cavities, which are similar to the...
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According to the experimental results of side polished fiber (SPF), a three dimensional optical waveguide model with longitudinal side polished transition zones is built. Based on the model, characteristics of optical...
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The effects of strain field, coalification degree and externally applied electronic field on the seepage performance of methane gas in coal are studied. It is shown that, the greater the stress (strain) in coal, the l...
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The effects of strain field, coalification degree and externally applied electronic field on the seepage performance of methane gas in coal are studied. It is shown that, the greater the stress (strain) in coal, the less the permeability coefficient of methane gas in the coal;when the stress (strain) is the same, the higher the coalificaton degree, the less the permeability coefficient;the stronger the externally applied electric field, the greater the permeability coefficient. The modified Darcy's law under the effects of stress field and electronic field are presented.
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