纤维聚合物筋混凝土梁正截面性能的研究

试验研究表明,纤维聚合物筋混凝土梁荷载挠度曲线以截面初裂为界限点分为两个线性阶段.正截面开裂前,荷载挠度曲线基本为线性,截面刚度较大;正截面开裂时,裂缝先在纯弯段出现,荷载挠度曲线出现转折点.随着荷载增加,纯弯段正裂缝发展,剪跨段斜裂缝产生并向梁的受压区加荷点扩展,梁的刚度较截面开裂前减少,荷载挠度曲线基本为线性直到梁破坏.在试验研究的基础上,探讨了纤维聚合物筋混凝土梁的非线性全过程数值分析方法,用计算机模拟了试验梁的跨中弯矩-挠度关系曲线,并用试验数据进行了验证.

Experimental Research and Numerical Analysis for Flexural Members Reinforced with Fiber Reinforced Polymer Bars

The test study indicates that the load deflection curves of concrete beams reinforced with fiber reinforced polymer bars can be divided into two linear stages against the initial cracking of the section when the tension failure occurs. Before the normal section cracks, the load-deflection curve is basically linear and the section rigidity is larger. As soon as the normal section cracks, the crack firstly appears in the flexural region. At this moment, the load-deflection curve has a turning point. With the increase of the load, the rigidity of the beam decreases compared with that before cracking because of the development of cracks in flexural region, and the formation and development toward the loading point of diagonal cracks. Generally, the load-deflection curve of this kind of beam is probably linear also. Based upon the stress-strain relationship of both fiber reinforced polymer bars and concrete, the nonlinear and whole-process numerical analytical method of concrete beams reinforced with fiber reinforced polymer bars is explored. The experimental curve of load-deflection is imitated through computer, and compared with the relevant data from the test.