矩形钢管混凝土压弯构件稳定计算的探讨

Approach to Compression-Bending Buckling Calculation for Concrete-filled Rectangular Steel Tube Member

矩形钢管混凝土压弯构件的稳定计算是《矩形钢管混凝土结构技术规程》中最重要的构件计算.但《规程》中压弯构件弯矩作用平面内稳定公式计算值,与国内数十根压弯试件的试验值比较发现,当钢管用钢材牌号Q345以上,混凝土强度等级超过C50且构件长细比较大时,部分试件的试验值较计算值偏低,个别低近30%,偏于不安全.应用弹性压弯构件考虑缺陷,以截面边缘屈服为准则的公式核算上述试件,计算值与试件的试验值更为吻合.故本文建议的稳定公式可为修订规程和设计人员参考.

The buckling calculation for compression-bending members of concrete-filled rectangular steel tube is the best important in（Technical specification for structures with concrete-filled rectangular steel tube members）. But yet when the strength of steel tubes to be made of steel material trade-mark is more than Q345, the concrete strength grade exceeds C50 and the member slenderness is fairly large , it can be found that the calculated values of buckling formulas in-plane bending of compression-bending members in the（Technical specification）are compared with the experimental values of internal dozens of test compression-bnding members, the experimental values of partial test members are lower, individual value lower near 30 percent , than the calculated value of the （Technical Specification）. That is to say, the formulas to compute buckling in（Technical specification）are on the less safe side. The buckling formula of an elastic compression-bending member with an initial eccentricity, to take the sectional edge yield as the buckling criterion , check above test members, the calculated values are in agreement with the experimental values of the test members. Therefore the buckling formulas, proposed in this paper, can be offered reference for technical specification to be revised and for designer.