混凝土曲线梁弹塑性力学行为分析

Analysis of Elastic and Plastic Mechanical Behavior for Concrete Curved Beams

针对曲线梁的几何特征,根据Timoshenko曲梁理论,提出每结点有6个自由度的三维曲梁单元。对于截面的内力计算,采用钢筋混凝土分块组合模型,在混凝土开裂前按线弹性理论计算,而对于混凝土开裂后,则引入钢筋混凝土软化桁架理论,提出混凝土开裂后截面内力重分布的计算方法。该方法充分考虑开裂后混凝土拉应力的贡献及箍筋的作用,从而建立预应力混凝土曲线梁非线性有限元分析模型,并编制计算程序。用该程序对一座两跨预应力混凝土曲线连续试验梁进行计算,并与试验结果进行比较,理论值与试验值符合良好,从而验证该模型是可靠的。

Based on the geometrical characteristics of curved beams and the Timoshenko＇s beam theory, the three-dimensional curved beam element including six degrees of freedom per node is established. A piece method is used to analyze the cross-section internal forces. Before concrete is cracked, the cross-section forces are calculated according to the linear elastic theory. After concrete is cracked, The reinforced concrete softened truss theory is conducted for calculating the internal forces of the cracked reinforced concrete cross-section. The actual contribution of cracked concrete and hoop steel can be considered. The nonlinear finite element analysis model for prestressed concrete curved beams is established, and the computer program is developed. With the program a two-spans continuous prestressed concrete experimental curved beam is calculated, the theoretical results are in good agreement with experimental results. Therefore, the reliability of the theoretical model is verified.