【作者】 李平；

【导师】 任伟；

【作者基本信息】 长安大学 ， 建筑与土木工程（专业学位）， 2018， 硕士

【摘要】 为改善FRP加固材料强度利用率低的现状,配合预应力FRP加固混凝土梁的研究,本文设计了一套纤维网主动加固施力系统,并首先对其张拉端和锚固端几何参数及工作应力进行了概念设计;其次,通过有限元分析对该装置进行了参数优化,如分离式楔形夹具中楔块的长度、锚固区混凝土螺栓的种植深度、螺栓的个数以及滑移量最小的锚固方式;再次,采用自主研发的双面张拉装置进行了锚固端可靠性试验,通过不同滑移量及荷载加载量的对比确定了波形锚具内部微齿形状及锚固区合理的锚固方式;最后,采用该加固系统进行了模型梁应用试验验证。通过以上研究得到以下结论:(1)自主研发的纤维网主动加固系统由张拉端和锚固端组成,概念设计阶段给出了张拉端、锚固端各个部件的基本尺寸,并通过力学计算给出了分离式楔形夹具的倾角为2度,波形锚具夹片中波形的个数为12个;(2)通过有限元分析确定了楔形夹具中楔块的长度为100mm,确定了不同等级混凝土在不产生损伤的前提下所需的最小螺栓埋置深度和单层、双层张拉所需螺栓的个数(分别为4个,6个),给出了不同锚固方式下纤维网在锚具内的滑移量值;(3)采用自主开发的双侧张拉装置进行了锚固端可靠性试验。通过不同滑移量和加载量的对比得出夹片内部波形微齿比三角形、直角形的锚固效果要更为有效。张拉单层纤维网的合理锚固方式为C,双层锚固方式为F。试验结果基本与有限元分析结果一致;(4)针对于主动加固系统提出了一套完整的PTRM加固钢筋混凝土梁施工工艺;(5)通过钢筋混凝土矩形梁上反拱试验,得出采用手动(人力)施加预应力的方式是可行的。试验梁跨中的反拱度和应变试验值与理论值误差在10%以内,再次证明本文研发加固系统的有效性和计算公式的正确性;(6)通过模型梁应用试验验证,在弯曲极限荷载破坏后,主动加固系统仍保持完好,并且纤维网的预应力损失较小;(7)应用本文研发的预应力纤维网主动加固施力系统能显著提高梁的开裂和屈服荷载。更多还原

【Abstract】 In order to improve the low utilization rate of FRP reinforced materials,and with the research of prestressed FRP reinforced concrete beams,this paper designs a set of active reinforcement force system for textile,and firstly the geometric parameters and working stress of tensioned and anchored ends.Conceptual design was performed;secondly,parameters of the device were optimized by finite element analysis,such as the length of the wedge in a separate wedge-shaped fixture,the depth of planting of concrete bolts in anchorage areas,the number of bolts,and the anchoring method with the smallest amount of slip.Thirdly,the anchorage end reliability test was carried out using a self-developed double-side tensioning device.The comparison of different slip amounts and load loadings confirmed the shape of the internal teeth of the anchorage and the reasonable anchoring method in the anchorage zone.Finally,This model of force application system was used to verify the model beam application test.Through the above studies,the following conclusions have been drawn:(1)The self-developed active reinforcement system for textile is composed of tensioned and anchored ends.The basic dimensions of the tensioned and anchored ends of the components are given in the conceptual design phase,and the inclination angle of the separated wedge-shaped clamps is given by mechanical calculation.Degree,the number of waveforms in the waveform anchor clip is 12;(2)Through the finite element analysis,the length of the wedge in the wedge-shaped fixture was determined to be 100 mm,and the minimum depth of the required bolts and the number of bolts required for single-layer and double-layer tensioning of different grades of concrete without damage were determined.(4 and 6,respectively).The slippage values of the textile in the anchorage device are given under different anchorage modes;(3)The anchorage end reliability test was carried out using a self-developed double tension device.Through comparison of different slip amounts and loadings,it was found that the internal micro-toothed teeth of clips are more effective than triangular and right-angle anchoring effects.The reasonable anchoring method for the tensioned single-layer web is C,and the double anchoring method is F.The test results are basically consistent with the results of the finite element analysis;(4)A complete description of the PTRM reinforced RC beams strengthening process with the mentioned system;(5)Through the reverse arch test on the rectangular reinforced RC beams,it is concluded that the manual(human)method of applying prestress is feasible.The error between the experimental value and the theoretical value of the anti-camber and strain test in the span of the test beam is within 10%,which proves again the validity of the research and development of the active reinforcement and the correctness of the calculation formula;(6)Through the application of the model beam experimental,the active reinforcement system remains intact after the bending ultimate load is destroyed,and the loss of prestress of the textile is small;(7)Applying the pre-stressed textile active reinforcement system developed in this paper can significantly increase the cracking and yield load of the beam.更多还原