考虑现浇砼收缩与滑移时叠合板承载力的研究

Researches on bearing capacity of composite slab considering the effect of shrinkage and slippage of cast-in-situ concrete

基于ANSYS有限元软件,文章应用弹簧单元和生死单元对混凝土叠合板进行建模,分别考虑叠合面滑移、二次受力、现浇层混凝土收缩等因素的影响,研究叠合板的极限承载力并与整浇板进行对比。计算结果表明:叠合面的滑移对承载力的影响较小;施工过程中的二次受力可有效提高叠合板的承载能力;同时,现浇层混凝土的收缩会明显削弱叠合板的整体承载能力,且承载力随着收缩微应变的增大而迅速减小。

The model of concrete composite slab is established by using the spring element and birth- and-death element based on the ANSYS finite element software. The slippage of laminate surface, secondary loading and shrinkage of cast-in-situ concrete are considered respectively to study the ulti- mate bearing capacity of composite slab and the results are compared with those of the uniform cast slab. The calculation results indicate that the effect of slippage of laminate surface on the bearing ca- pacity is small. The secondary loading in construction process can increase the bearing capacity effec- tively. Meanwhile, the shrinkage of cast-in-situ concrete can weaken the bearing capacity obviously. The bearing capacity is lowered rapidly with the increase of micro-shrinkage strain.