CFRP拉索研制及其力学性能研究

RESEARCH ON CARBON FIBER REINFORCED POLYMER STAY-CABLE AND ITS MECHANICAL PROPERTY

设计了一种新型CFRP拉索结构与制索方法,改变了以往CFRP拉索中CFRP筋平行排布的方式,将索体中CFRP筋进行扭结,在锚固端将CFRP筋发散开来,对研制出来的CFRP拉索进行了静载拉伸试验与拉-拉疲劳试验研究。试验结果表明:提出的新型CFRP拉索结构与制索方案切实可行,采用2.5°~3.5°扭转角与2.5°发散角适用于CFRP筋材,轻微扭转与弯折并不会导致筋材过早发生破坏;新型CFRP拉索的静载拉伸锚固效率大于95%,通过250万次疲劳加载试验,锚固部位没有损伤,拉索断丝率小于5%;随着疲劳加载循环次数的增加,CFRP拉索的弹性模量基本不变,拉索锚固端索体伸出量、筋材及锚板在锚具后端的回缩量都不超过1mm。

This paper studied a new kind of CFRP stay-cable and its mechanical property. A new structure of CFRP stay-cable was proposed and manufactured. Instead of parallel arrangement of the CFRP tendons,CFRP tendons in new structure of CFRP stay-cable is twisted together in cable and diverge in the anchor end. The tensile strength and tension-tension fatigue behaviour of the new structure of CFRP stay-cable were tested. Experimental results show that the new structure of stay-cable and its manufacturing process are feasible. The twist angle of 2.5°~3.5° and the divergence angle of 2.5°are suitable for CFRP tendons,and the slight twist and bending of tendons will not lead to premature failure. The static load tensile anchorage efficiency of the new CFRP stay-cable is more than 95%. After 2.5 million fatigue loading tests,the anchorage part is not damaged and the broken tendon rate of the cable is less than 5%. With the increase of fatigue loading cycles,the elastic modulus of the CFRP cables basically remains unchanged. The cable extension at the anchorage end and the retractions of the tendons and anchor plates at the back end of the anchorage are less than 1 mm.