体外预应力加固钢筋混凝土简支梁的设计参数研究

Research on Design Parameters of Reinforced Concrete Simple-supported Beam Strengthened by External Prestressing

为研究4种参数对体外预应力加固钢筋混凝土简支梁的承载性能影响,先用ANSYS软件建立有限元模型,对既有试验研究进行数值模拟,将试件承载力、破坏形态、荷载-位移曲线的有限元结果与试验结果进行了对比分析,结果表明:有限元计算结果与试验结果吻合较好。然后利用有限元方法进行扩大参数分析,共计算了59个模型,从而研究了钢束截面面积Ap、转向器位置、钢束转向角度θp和钢束形心距梁侧面距离Hd对构件承载性能的影响,结果表明:随着Ap的增大,构件极限承载力存在“回归值”,此“回归值”可用于确定最佳钢束用量;设两个转向器时,转向器宜布置于距支点L/6~L/4位置处;当钢束张拉控制应力σcon较大时,θp取值不宜过大;σcon较小时,θp取值不宜过小;Hd取值宜小不宜大。

In order to researchthe influence of four parameters on the bearing behavior of reinforced concrete simply-supported beam strengthened by externally prestressing,firstly the ANSYS software was used to establish the finite element model to conduct numerical simulation of existing experimental research.The finite element results of specimen bearing capacity,failure mode and load-displacement curve were comparative analyzed with the experimental results.The results show that the finite element calculation results are in good agreement with the experimental results.Then,the expanded parameter analysis was carried out by using the finite element method,and a total of 59 models were calculated.Thus influences of section area Ap of strand,position of steering gear,steering angleθp of strand,distance Hd between the strand centroid and the side of the beam on the bearing behavior of components were studied.The results show that with the increase of Ap,there is a‘regression value'of the ultimate bearing capacity of members,which can be used to determine the optimal strand quantity.When two steering gears are installed,the steering gears should be placed at a distance of L/6~L/4 from the fulcrum.When the tension control stressσcon of strand is larger,the value ofθp should not be too large,and whenσcon is smaller,the value ofθp should not be too small.The Hd should be small rather than large.