预应力CFRP平板式锚具优化设计与应用

Optimization design and application of prestressed CFRP plate anchorage

针对平板式锚具存在需在混凝土表面开槽、有效行程短、不可重复利用等问题,开展了平板式锚具优化设计与应用研究,提出了一种无须在结构基面设置扣槽,占用空间小、碳纤维增强材料(CFRP)板有效利用长度更长,轻质高强、可重复利用的预应力CFRP平板式锚具。有限元分析表明:在计算荷载作用下,锚具性能满足预应力CFRP加固需要,锚固支座、锚板和锚栓最大应力值分别为133、76、94 MPa,总体应力分布均匀,均小于其屈服强度,最大变形值为0.056、0.024、0.028 mm,保证锚具不先于结构破坏。随着锚栓直径与锚板厚度增大,锚具内部应力与变形均有所改善,其中锚栓直径变化对锚栓与锚板接触部分受力影响较大;锚板厚度对混凝土表面与锚栓接触部分受力影响较大,故建议锚栓直径为18 mm,锚板厚度为20 mm。实际工程应用表明该锚具使用效果良好。

The research showed that plate anchorage need to be grooved on the concrete surface,with short effective travel and cannot be reused.The optimization design and application of plate anchorage has been studied.A new plate anchorage was put forward,which did not need to set the buckle groove on the structural surface,the space occupied was small and the effective utilization length of CFRP board was longer,prestressed CFRP plate anchorage was lightweight and high-strengthand can be reused.The finite element analysis showed that under the calculated load,the anchorage performance can meet the needs of prestressed CFRP reinforcement.The maximum stress values of the anchorage bearing,anchor plate and anchor bolt were 133 MPa,76 MPa,and 94 MPa,respectively.The overall stress distribution was uniformand less than their yield strength.The maximum deformation values were 0.056 mm,0.024 mm,and 0.028 mm,respectively.The anchorage would not be damaged before the structure.With the increasing of the diameter of anchor bolt and the thickness of anchor plate,the internal stress and deformation of the anchorage were improved.The change of the diameter of anchor bolt has a greater impact on the force on the contact part of anchor bolt and anchor plate.The thickness of the anchor plate has a great influence on the stress of the contact part between the concrete surface and the anchor bolt.The recommended diameter of the anchor bolt was 18 mm,and the thickness of the anchor plate was 20 mm.The real bridge application showed that the prestressed CFRP plate anchorage has a good effect.