预应力钢与高强混凝土组合梁有限元分析

Numerical Analysis of Finite Element Method of Composite Beam Made of Pre-stressed Steel High and Strength Concrete

目的研究预应力钢与高强混凝土组合梁从加载到破坏的全过程,分析其力学性能,为工程应用提供可靠的理论依据.方法采用大型有限元软件ANSYS,对预应力钢与高强混凝土组合梁进行了空间非线性分析,在组合梁的有限元模型中,钢梁采用壳单元,混凝土采用体单元,混凝土中的普通钢筋通过单元实常数确定,预应力钢筋采用线单元,预加应力通过单元实常数确定。采用弹簧单元考虑了混凝土翼缘板同钢梁间的滑移;采用非线性材料本构模型关考虑了钢材和混凝土的材料非线性特性.结果计算得到了组合梁在不同加载状态的应力、应变,荷载-变形曲线,预应力钢筋增量曲线,滑移沿梁长分布曲线等,并与试验研究进行了比较.分析表明,高强混凝土和钢材的强度都得到了充分发挥.结论计算结果与已有试验结果较为吻合,因此,可以利用有限元方法研究组合梁的工作性能,代替部分试验研究.

This article aims to study the process from loading to destroying the pre-stressed steel concrete composite beam to analyze its capability and give an analytical method for engineering. Based on ANSYS programs, spatial nonlinear analysis about composite beam made of pre-stressed steel and high strength concrete is done in this paper and, as for steel beam, shell units are used; and for concrete, volume units are used. The ordinary steel bars in the concrete are defined through the real constant; the pre-stressed steel bars are adopted line units, and the pre-stress is definite through real constants of the unit. Slips between concrete slab and the steel beam are considered by adopting the spring unit; the material nonlinear property of steel and concrete is considered through stress-strain relation of nonlinear material. The stress and strain under different loading conditions, load-displacement curve, pre-stressed steel bars stress increment curve and slip distribution curve along the length of beam are received through calculation of the composite beam in this paper. The numerical results show that the pre-stressed steel-concrete composite beam is a new structure with good behavior. The test research is also discussed to contrast the difference. The results of finite element analysis and test research are similar. It proves that the finite element analysis can be used instead of some test research.