圆CFRP-钢管混凝土构件的受弯性能

目的初步了解圆截面CFRP-钢管混凝土受弯构件的静力性能，为进一步的研究奠定基础．方法在8根圆CFRP-钢管混凝土受弯构件静力试验的基础上，分析钢管和CFRP筒的环向和纵向的协同工作，环向应变分布规律，屈服荷载时纵向应变比较。平截面假定，挠度以及纵向CFRP层数对承载力提高率的影响等问题．结果从加载之初直到最大承载力，钢管和CFRP筒的环向应变基本一致，纵向应变也基本一致。表明两种材料在环向和纵向都可以协同工作；纵向受压最大点的环向拉应变最大。纵向受拉最大点的环向压应变最大，其余点的环向应变介于二者之间；对于同一系列的试件。同一荷载下钢管的纵向应变随着纵向CFRP层数的增大而减小，但试件达到屈服荷载时的应变值却十分接近．结论从加载之初直到大约0．7倍的极限承载力。钢管纵向应变沿截面高度的分布符合平截面假定；在同一荷载下，挠度随着纵向CFRP层数的增大而减小，纵向CFRP可以显著提高试件的刚度；对于同一系列的试件。承载力提高率随着纵向CFRP层数的增大而增大．

Bending Performance of Concrete Filled Circular CFRP-Steel Tubular Members

Eight concrete filled circular steel-CFRP tubular members under bending were tested in order to understand static performance of these kind of members initially and to provide some basis for further research.It was found that the circumferential strain and the longitudinal strain between steel tube and CFRP tube are the same approximately from 0 load till the ultimate load bearing capacity and this means that these two kinds of materials could cooperate circumferentially and longitudinally.Circumferential strain distribute does not uniformly: circumferential strain at the point that longitudinally pressed largest is the biggest and circumferential strain at the point that longitudinally tensioned largest is the smallest,circumferential strain at other points are middle.For the same series members,steel tube longitudinal strain decrease as longitudinal CFRP layers increase at the same load and longitudinal strain are the same approximately at yield load.Steel tube longitudinal strain along the cross-section depth obeys the plain section assumption from 0 load till about 0.7 times the ultimate load bearing capacity.The deflection decreases as the longitudinal CFRP layers increase at the same load and the longitudinal CFRP would enhance members' rigidity significantly.Ultimate load bearing capacity enhancement ratio increases as the longitudinal CFRP layers increase for members with the same steel tube outer diameter.