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对于高性能碳纤维增强聚合物复合材料(CFRP)筋混凝土梁,研究几何非线性组合壳单元模型,对预应力CFRP筋混凝土梁进行了全过程分析。引入Von Karman理论,推导了局部坐标系下Piola-Kirchhoff应力矩阵和几何刚度矩阵;分别采用组合壳单元和分层壳单元模拟预应力CFRP筋和玻璃纤维增强聚合物复合材料(GFRP)筋,并推导了CFRP筋对组合壳单元刚度矩阵的贡献,同时采用Heterosis选择积分技术以避免剪切锁定和零能量模式,研制了相应的非线性计算程序。计算结果与试验数据对比可知,挠度发展规律和预应力CFRP筋应变发展规律均吻合良好,说明了研究单元的有效性及研制程序的正确性;CFRP筋具有高强度性能,梁试件破坏时CFRP筋均未失效;利用预应力CFRP筋应变重分布系数研究了梁的刚度退化规律,表明采用GFRP筋代替普通钢筋在加载后期会使梁的刚度退化减小。
For high-performance CFRP reinforced concrete beams, the geometric nonlinear composite shell element model is studied and the whole process of prestressed CFRP reinforced concrete beams is analyzed. Von Karman theory is introduced to derive Piola-Kirchhoff stress matrix and geometric stiffness matrix in local coordinate system. The composite shell element and layered shell element are used to simulate prestressed CFRP tendons and glass fiber reinforced polymer composites (GFRP) The contribution of CFRP tendons to the stiffness matrix of composite shell elements is deduced. At the same time, Heterosis selection integral technique is used to avoid the shear locking and zero energy model. The corresponding nonlinear calculation program is developed. Comparing the calculated results with the experimental data, we can see that the law of deflection development and the law of strain of prestressed CFRP tendons are in good agreement, which shows the validity of the research unit and the correctness of the development procedure. CFRP tendons have high strength properties, CFRP The results show that the stiffness degradation of beam is studied by using the strain redistribution coefficient of prestressed CFRP tendons, which shows that the stiffness degradation of beam can be reduced by using GFRP tendons in the later stage of loading.