摘要
对不同应变速率(8. 58×10-3,4. 29×10-2,2. 15×10-1s-1)和索径(5. 2,15. 2,50mm)的5组钢绞线进行了动力试验。结果表明,不同应变速率下的应力-应变曲线形状大致相同;应变速率每增加5倍,钢绞线的屈服应变约下降3%,极限应变约下降5%,极限应力和屈服应力约提升3%;随应变速率的提高,钢绞线在达到极限状态前断丝的趋势增加;钢绞线中芯单丝的滑移一般发生在动荷载的低速加载阶段,并且钢绞线主要发生延性断裂,断口形式为铣刀式断口,属于宏观延性断口。
Dynamic tests of five groups of steel strands with different strain rate( 8. 58×10-3,4. 29×10-2,2. 15×10-1 s-1)and cable diameter( 5. 2,15. 2,50 mm) were carried out. The results show that the shape of the stress-strain curve is approximately the same under different strain rate; yield strain decreases by 3% and the ultimate strain decreases by 5%and the ultimate stress and yield stress increase by 3% for each five-fold increase of strain rate; the tendency of steel strand breakage increases before reaching the ultimate state with the increase of strain rate; and the slippage of the core monofilament in the steel strand usually occurs in the low-speed loading stage of dynamic load,and the ductile fracture mainly occurs in the steel strand,with the fracture form of milling cutter fracture which belongs to macro ductile fracture.
引文
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