摘要
对组合梁施加体外预应力,可有效提高截面的开裂弯矩,然而预应力的施加降低了板件的屈曲临界应力,减小了截面的转动能力。考虑局部屈曲的影响,对体外预应力组合梁进行了有限元非线性稳定分析,计算结果与试验实测值吻合,通过改变截面参数对27组组合梁在不同综和力比,不同翼缘宽厚比,不同腹板高厚比,不同剪跨比下的转动能力进行了计算,研究了影响转动能力的长细比参数,回归计算转动能力、计算参数和计算公式。研究表明:文中提出的长细比参数和公式与模拟结果相关程度高,形式简单,可以用来计算Ⅰ、Ⅱ类组合梁的转动能力。
In hogging moment regions, the cracking resistance of the beams can be effectively increased on adding prestressing to the composite beams with external tendons, The rotation capacity of a composite beam prestressed with external tendon in hogging moment regions is governed by local buckling. With tools of abaqus, inelastic finite element buckling analysis of composite beams in negative bending was performed, and the FE results are found agree well with the test results. By varying cress - section parameters, 27 groups of composite beams under negative bending with initial geometric imperecfion are studied by means of the FE method. The slenderness of the studied beam is defined and the formula for calculating the rotation capacity is presented. The formulae are simple in form , in good agreement with the FE result and expected to be useful for designing the composite beams of class Ⅰ and Ⅱ .
出处
《河北工程大学学报（自然科学版）》
CAS
2009年第1期14-20,共7页
Journal of Hebei University of Engineering:Natural Science Edition
基金
国家自然科学基金项目(50678132)
