中文摘要：

给出了不同材料强度的无粘结预应力混凝土（UPC）梁抗弯强度和结构性能的分析研究结果。建立了基于有限元方法并结合一种弧长算法的适用于UPC梁非线性全过程分析的数值模型。提出的算法能较好地处理梁加载过程的响应变化，可穿越梁破坏前可能出现的极值点问题。利用该数值模型分析评估了混凝土轴心抗压强度和非预应力筋屈服强度对UPC梁性能以及无粘结预应力筋极限应力的影响。所得结果可为UPC梁的优化设计提供参考。

英文摘要：

The results of analytical investigation on the flexural strength and structural behavior of unbonded prestressed concrete （UPC） beams with various material strengths were presented. A numerical model based on the finite element method incorporating an arc-length algorithm for nonlinear full-range analysis of UPC beams was developed. The proposed solution algorithm can deal well with the changes of response during loading and is capable of proceeding past the possible limit points prior to the failure of the beams. The influence of concrete cylinder compressive strength and yield strength of nonprestressed steel on the behavior of UPC beams and the ultimate stress in unbonded tendon were analytically evaluated using the proposed numerical model. The acquired results provide a reference for the optimal design of UPC beams.