| Carbon Fiber Reinforced Polymer/Plastic (CFRP) tendon has many excellent properties, such as high strength, low weight, fatigue-resistant and corrosion-free. So CFRP composite is the ideal material which has been more and more used in prestressed reinforcing tendons as well as structure strengthening. However, the weakness of CFRP composite in transverse direction and its sensitivity to notching make it hard to anchorage. Meanwhile, when used in the structure design under the fatigue load, CFRP-tendon’s anti-fatigue performance must be considered.First, to the problems that mentioned, this dissertation studies the radial compressive stress of CFRP tendons in anchorage zone. Then, by certain parameter analyses, the optimum parameters in anchoring were determined. Various performance indexes were also improved. So that it can provide academic reference for researching and exploiting the wedge-type anchorage of CFRP-tendon.Anti-fatigue performance test shows that the new type of anchorage can be used in fatigue test under the cyclic loading, and the CFRP-tendon occurs brittle failure code. Tests showed that the change of the CFRP-tendon’s tensile stiffness can be divided into three stages:rising stage, little changes, rapid decline. The average of the conditional fatigue limit of 1×106 cycles is 1501.4MPa, about 75% of static strength, has once again proven CFRP-tendon’s excellent fatigue performance.Based on the above analysis, this article employs stress-life curve model and fits the formula to predict the fatigue life. This paper also proposed a new three parameters S-N curve model. More over, this method is available and to a certain degree predicts the fatigue life of the carbon fiber reinforced polymer. Curves shows that the fatigue life test of carbon fiber reinforcement to reach 2 million times the corresponding stress amplitude is about 392 MPa. And the fatigue life curve comparison shows that the fatigue property of CFRP tendons is far better than high-strength bars and strands.Based on the residual stiffness model, the secant modulus is used to describe the damage. Fitting results shows that the reliability of the residual stiffness model in middle fatigue life is high. It turned out that, the law of change of rigidity of carbon fiber polymer can better apply the residual stiffness model. At the same time, this paper proposes a new residual stiffness model to predict the residual stiffness. The results showed the model has a better precision and the model itself has the actual physical meaning, can intuitively reflect the damage condition of CFRP tendons.Finally, this paper studied the anti-fatigue performance of CFRP tendons anchor systems by finite element analysis. By using the large finite element method software MSC Fatigue, fatigue stress monitoring and fatigue life prediction were implemented. By the normal stress approach, the simulation results are compared with the experimental results and verify the accuracy of the simulation method. The results suggest a reasonable design and a feasible process arrangement. The finite element analysis experiments show that the structure plan and design in this paper was available. |
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