无粘结预应力混凝土梁的强度与变形特性研究

Research on Strength and Deformation Characteristics of Unbonded Prestressed Concrete Beams

给出了无粘结预应力混凝土梁强度和受力性能的分析结果。建立了适用于无粘结预应力混凝土梁非线性全过程分析的有限元简化模型,利用该模型探讨了跨高比、有效预应力和加载方式这3种参数对无粘结预应力混凝土梁弯曲性能以及无粘结预应力筋极限应力的影响。分析结果表明,跨高比对无粘结预应力筋极限应力无明显影响,增大无粘结预应力筋的有效预应力能显著提高梁的开裂和极限荷载,加载方式对梁的受力性能有着非常重要的影响。

The analytical results for strength and behavior of unhonded prestressed concrete beams were presented.A simplified finite element model for nonlinear full-range analysis of unbonded prestressed concrete beams was developed. The influences of three parameters including span-depth ratio, effective prestress and load type on the flexural behavior of unbonded prestressed concrete beams and the ultimate stress in unbonded tendons were discussed using the proposed model. The analytical results show that the effect of span-depth ratio on the tendon stress is not obvious; increasing the effective prestress of unbonded prestressing steel remarkably enhances the cracking and ultimate loads of the beams; load type has very important influence on the beam behavior.