基于增设截面的体外预应力梁抗弯性能分析

Flexural Performance Analysis of the Externally Unbonded Prestressed Beam Based on the Adding Section

采用OpenSEES对体外预应力梁进行抗弯性能分析。由于采用传统方法易造成体外预应力筋和梁变形不同步,如果预应力筋和梁分别设置截面,预应力筋截面的应力难以准确施加到梁截面锚固处,为此,提出增设截面建模方法,在预应力筋截面增设混凝土截面。结果表明,采用增设截面的方法建模,有效解决了预应力定位问题,梁出现反拱,与梁实际状态一致,增设截面高度对抗弯承载力影响显著,建议与原混凝土截面高度一致,预应力筋应力增量随转向块个数增加而增大。

OpenSEES is used to analyze the flexural behavior of the externally prestressed concrete beams.The deformation of externally prestressing tendons and the beams can be easily out of sync by traditional method.If the section of the prestressing tendons and beams are set separately,the stress of the prestressed tendon's section is difficult to be applied to the anchorage of the beam's section. Therefore,the modeling method of adding the section is put forward.The section of concrete is added to the section of prestressed tendon.The results show that the beam has an inverted arch by adopting the method of adding section on the problem of effective prestress positioning.This state is consistent with the actual state of the beam.The height of the additional section has a significant influence on the flexural bearing capacity.The stress increment of the prestressing tendon increases with the increased number of the steering blocks.