钢筋砼框架考虑斜裂缝影响的非线性全过程分析

Nonlinear Full-Range Analysis of R.C. Frame Considering the Effect of Diagonal Cracks

本文通过对一些约束梁、约束柱及连续梁抗剪试验资料的分析研究，采用斜压场模型模拟有反弯点的剪跨区段当斜裂缝出现后剪力作用下的受力状态，并考虑剪跨比的影响及纵筋的暗销作用，导出了剪力、剪切变形、轴力之间的关系。用此模型对不同条件的５８根剪切破坏的约束梁、柱进行了计算比较。同时，将模型引入框架非线性分析中的单元刚度矩阵及固端力列阵，编写了框架非线性全过程分析程序，对一定数量发生弯曲剪切破坏的两跨连续梁进行了计算比较，计算结果与实测结果符合较好。本文进行了三榀门式框架及二根两跨连续梁的试验，用上述程序进行了框架、连续梁考虑斜裂缝对内力重分布及构件变形影响的比较分析。

Based on the analysis of some shear-resistant test results of restrained beams, restrained columns and continuous beams, the diagonal compression field model is utilized to simulate the mechanical state of shearing in shear span region containing point of inflection after the occurrence of diagonal crack, in which the dowel action of longitudinal steel and shear span ratio are taken into consideration. A relation among the shear force, shear deformation and axial force is thus formulated. The model is adopted to calculate and compare the 58 restrained beams and columns which failed in shear under different conditions. Meanwhile,the model is introduced into the element stiffness matrix and the fixed end reaction force matrix in a non-linear analysis of R.C. frame, and a corresponding computer program has been developed. Some two-span continuous beams failed in bending or shear were analyzed by this program and comparison shotwed that there is a good agreement between the calculated and test results. Furthermore, 3 frames and 2 two-span continuous beams were tested by the authors, and the program was used to analyze and compare the effect of diagonal cracks on internal force redistribution and member deformations.