论文部分内容阅读
采用混凝土和钢筋的增量型温度-应力耦合本构模型,在充分考虑高温下无黏结预应力筋总变形协调条件和其对梁单元有限元列式影响的基础上,将无黏结预应力筋内力与未知结点位移共同作为待求列矢,推导高温下无黏结预应力混凝土受弯构件非线性有限元全过程分析的增量有限元格式,建立其高温下非线性有限元计算模型,并提出其非线性有限元平衡方程组的求解方法,编制NAUPCLF非线性有限元程序,并对进行的高温试验及有关试验资料完成实例计算。结果表明,计算数值基本能反映其高温下变形及预应力筋应力的变化规律,计算理论较充分地表现了无黏结预应力混凝土受弯构件的无黏结特性及高温受力特点,可为建立高温下无黏结预应力混凝土受弯构件的耐火极限计算方法、进一步深入研究预应力混凝土结构的抗火性能和完善其基于抗火特性的设计方法提供手段和参考。
Adopting the incremental temperature-stress coupling constitutive model of concrete and steel bar, on the basis of fully considering the coordination conditions of total deformation of unbonded prestressed tendons under high temperature and their influence on the finite element method of beam elements, the unbonded prestressing tendons The internal force and unknown node displacement together as a waiting list vector to deduce the incremental finite element method of non-linear finite element analysis of non-bonded prestressed concrete flexural members under high temperature. The nonlinear finite element model is built The method to solve the nonlinear finite element equilibrium equations is proposed and the nonlinear finite element program of NAUPCLF is compiled. The high temperature experiments and the related experimental data are completed. The results show that the calculated values basically reflect the deformation of the prestressed tendons under high temperature and the stress variation of prestressed tendons. The calculation theory fully shows the characteristics of non-bond and high temperature stress of unbonded prestressed concrete flexural members, Under non-bonded prestressed concrete flexural members of the refractory calculation method to further study the fire resistance of prestressed concrete structures and perfecting its design method based on fire resistance provide means and reference.