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| Nonlinear analysis of carbon fiber sheets confined high strength concrete circular column subjected to axial load and lateral shear |
| Received:October 26, 2007 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx20096025 |
| KeyWord:CFRP confined concrete high strength concrete circular column nonlinear analysis |
| Author | Institution |
| 王震宇 |
哈尔滨工业大学 土木工程学院,哈尔滨 |
| 王代玉 |
哈尔滨工业大学 土木工程学院,哈尔滨 |
| 芦学磊 |
天津水泥工业设计研究院有限公司,天津 |
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| Abstract: |
| To analyze the seismic behavior of high strength concrete circular columns confined with carbon fiber sheets (CFS) in the plastic hinge region, a nonlinear analytical procedure was developed, which can obtain the descending branch of shear-tip deformation curves of columns subjected to axial load and lateral shear. The Mander stress-strain model was used for concrete confined with hoops and for unconfined concrete cover. The stress-strain model proposed by ACI 440.2R-08 was used for FRP-confined concrete. The numerical simulation results agree well with experimental results. Influences of axial compression ratio, concrete strength, height and layers of CFS wrapping, longitudinal reinforcement ratio on shear-tip deformation curves were analyzed using this procedure. The results indicate that the lateral loading capacity of columns begins to decrease when the axial compression ratio exceeds 0.55, and the failure mode of columns transfers from ductile tensile failure to brittle compressive failure. For columns with shear span ratio greater than 3.0, when the height of wrapped CFS in the plastic hinge region exceeds 1.2D (D is the diameter of circular column), the seismic performance can be improved to a level equivalent to full CFS-wrapped columns. For high strength concrete from 50MPa to 80MPa, three or four layers of CFS wrapping are reasonable. With an increase of the longitudinal reinforcement ratio, the shear capacity and ductility level of columns show a corresponding enhancement. |
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