PMM纤维铰在排架结构刚度折减系数取值中的运用

目前钢筋混凝土排架结构的设计多数基于弹性假定。但在实际工程中,排架结构受力常伴随着混凝土开裂,钢筋与混凝土黏结滑移等现象,而排架结构的二阶效应常使结构刚度退化进一步加重。因此,在对排架结构进行分析的过程中,对材料非线性时二阶效应的计算就显得十分必要。在工程设计中较为切实可行的方法是引入考虑刚度折减的弹性二阶分析法,其准确性很大程度取决于刚度折减系数的取值,笔者试图通过基于材料模型的PMM纤维铰找到合理的排架结构刚度折减系数。

Application of PMM fiber hinges to the value of stiffness reduction coefficient of bent structure

At present, most of the design of reinforced concrete bent structures is based on elastic assumption. However, in practical engineering, the stress of bent structure is often accompanied by the cracking of concrete and the bond slip between reinforcement and concrete, etc. The second-order effect of the bent structure often aggravates the structural stiffness degradation. Therefore, it is necessary to calculate the second-order effect of material nonlinearity in the analysis of bent structure. A practical method in engineering design is to introduce the elastic second-order analysis with stiffness reduction considered, and its accuracy depends largely on the value of the stiffness reduction factor. This paper tries to find a reasonable stiffness reduction factor of the bent structure through the PMM fiber hinge based on the material model.