碳纤维复合材料拉索的非线性力学性能

Nonlinear mechanic behaviors of CFRP cables

采用解析法分析碳纤维复合材料(CFRP)拉索的非线性力学性能,通过与钢拉索对比分析,得出了CFRP拉索的受力特点。由于密度低,CFRP拉索自重应力、垂度约为钢拉索的1/5,承载效率也比钢拉索高许多,其承载极限长度为钢拉索的7倍,且随跨径增大,钢拉索的等效弹性模量下降非常快,而CFRP索仍保持较高值。由于CFRP线胀系数比钢材的线胀系数要小得多,约为其1/14,在温差与约束相同时,无垂度CFRP索温度应力仅为无垂度钢索的1/23。当有垂度时,钢索的温度应力降低,CFRP索的温度应力变化很小。

Interest in the use of Carbon Fiber Reinforced Polymer （CFRP） in lieu of steel cables in cablestayed bridges is increasing due to the high-strength, light-weight and corrosion-free properties of such materials. The sag effect, effective modulus, temperature effect and potential ultimate span of CFRP cables have been discussed on the basis of nonlinear comparative studies with steel cables. It shows that CFRP cable is of higher loading efficiency, longer ultimate span and greater effective modulus due to its higher strength and lighter weight, especially to those extra long cables. Its ultimate span is about 7 times of that of steel cable, the thermal stress in carbon cable is only about 5% of that in steel cable at the same temperature difference and boundary condition, and the thermal stresses both in carbon cable and in steel cable with sag will decrease.