预应力钢与高强混凝土组合梁徐变效应分析

Analysis of Creep Effect on Prestressed Steel Composite Beams with High-Strength Concrete

在长期荷载作用下,预应力钢与高强混凝土组合梁中的混凝土将产生徐变和收缩变形,从而导致带有柔性剪力连接件的组合梁中混凝土板和钢梁的应力发生重分布·采用按龄期调整有效模量与平均应力相结合的方法,利用预应力组合梁中混凝土板、钢梁及预应力钢索之间变形关系,分别建立了简支预应力组合梁的弹性分析和考虑混凝土徐变效应影响的黏弹性分析数学模型,研制了其数值计算模拟程序·通过计算示例,分析不同时间段内预应力组合梁内力变化、应变分布、弯曲变形及交接面相对滑移及其随时间的变化等·

Under the action of long-time loading, creep and shrinkage deformation will come to being in the high-strength concrete of a prestressed steel composite beam with flexible shear connectors, thus causing the stress to redistribute in concrete slab and steel beam. Introducing a comprehensive method combining the age-adjusted effective modulus with mean stress and considering the deformation relationships among the concrete slab, steel beam and prestressed cable, two mathematic models are developed separately for the elastic analysis of the simply supported composite beam and the viscoelastic analysis of the same beam with the creep effect on the concrete taken into account. With the numerical computation/analysis program discussed through an example, the moment, strain variation, deformation properties and the interface slip of the simply supported composite beam are analyzed.