循环荷载作用对CFRP筋力学性能的影响

发布时间：2018-04-27 11:51

本文选题：桥梁工程 + CFRP　；参考：《复合材料学报》2014年01期

【摘要】：应用于桥梁工程的碳纤维增强复合材料(CFRP)筋通常受循环荷载作用,导致其力学性能的退化,这将影响桥梁结构的受力。为了考察循环荷载作用对CFRP筋力学性能的影响,首先利用静载试验对CFRP筋的初始力学性能进行了检测,然后结合静载试验结果并利用疲劳试验考察了各阶段循环荷载作用对CFRP筋弹性模量、松弛及抗拉强度的影响。研究结果表明,极限拉力作用下CFRP筋的弹性模量较初始状态高约5%,对于CFRP筋构件的变形对结构内力有较大影响的结构,在设计阶段建议适当地考虑CFRP材料的非线性问题;桥梁工程中,经200万次正常使用设计循环荷载作用的CFRP筋,其弹性模量和松弛性能较初始状态未发生明显退化,经应力幅为4.3%的极限抗拉强度的循环荷载作用后,CFRP筋的抗拉强度提高了1.2%,但应力幅提高至7%的极限抗拉强度时,其抗拉强度与初始状态相比无明显变化。
[Abstract]:CFRPs used in bridge engineering are usually subjected to cyclic loading, which leads to the degradation of mechanical properties, which will affect the force of bridge structures. In order to investigate the effect of cyclic load on the mechanical properties of CFRP bars, the initial mechanical properties of CFRP tendons were tested by static load test. Then the effects of cyclic load on the elastic modulus relaxation and tensile strength of CFRP tendons were investigated by fatigue test combined with the results of static load test. The results show that the elastic modulus of CFRP tendons is about 5% higher than that of the initial state, and the nonlinear problem of CFRP material should be considered properly in the design stage. In bridge engineering, the elastic modulus and relaxation property of CFRP tendons, which are subjected to the design cyclic load for 2 million times, do not degenerate obviously compared with the initial state. The tensile strength of CFRP tendons increased by 1.2% after cyclic loading with the ultimate tensile strength of 4.3%, but when the stress amplitude was increased to 7% of the ultimate tensile strength, the tensile strength of CFRP bars did not change obviously compared with the initial state.
【作者单位】：宁波大学建筑工程与环境学院;浙江工业大学建筑工程学院;西南交通大学土木工程学院;
【基金】：国家自然科学基金(51208269) 浙江省教育厅科研项目(Y201222960) 桥梁工程结构动力学国家重点实验室开放基金(201202)
【分类号】：TB33;U444

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