CFRP筋用3D打印同源材料复合型锚具的静载锚固性能

Static load anchoring performance of composite anchorage with 3D printing homologous materials used for CFRP bars

  • 摘要: 为实现碳纤维增强树脂基复合材料(carbon fiber reinforced polymer-CFRP)筋的高效锚固,并量化关键参数对同源材料锚具锚固效率的影响规律,推进3D打印CFRP技术在桥梁工程中的应用,本文从试验及仿真角度开展了较为系统的探索。首先,基于3D打印CFRP技术设计并制备了一种新型的CFRP筋用同源材料并式复合型锚具。其次,遴选锚杯长度、粘结介质厚度、夹片数量、夹片预紧倍率、灌胶杯形状等关键参数,进行短期静载张拉试验,探究不同参数对锚具静载锚固性能的影响规律。此外,基于3D打印CFRP的基础力学参数,构建了能精确表征3D打印并式复合型锚具性能的仿真模型。结果表明:本次研究的锚固系统有三种失效模式,即筋的拉断破坏、剪切破坏、滑移失效。锚具的锚固效率随着锚杯长度、预紧倍率及夹片数量的增大而提高,锥台型胶体相较于直筒型胶体有更高的锚固效率。所研究的锚具在同时满足锥台型粘结介质、预紧倍率100%、锚杯长度120 mm、3片夹片等条件下,锚固效率达到103.33%,满足规范要求。该最优构型结构完整,不会发生破坏,随着荷载增加,CFRP筋-胶界面上会出现应力重分布。此外,试验数据与仿真结果误差均控制在10%以内,且两者趋势基本一致,表明所构建仿真模型具有较好的预测效果。综上,验证了3D打印同源材料锚具锚固单根CFRP筋的有效性,为推进CFRP筋用锚具的同源材料化提供了理论基础及技术支撑。

     

    Abstract: To achieve efficient anchoring of carbon fiber reinforced polymer (CFRP) bars and quantify the influence of key parameters on the anchoring efficiency of the homologous materials anchorages, as well as to promote the application of 3D printing CFRP technology in bridge engineering, a systematic exploration was conducted from both experimental and simulation perspectives. Firstly, a new type of parallel composite anchorage made of homologous materials for CFRP bars was designed and fabricated using 3D printing CFRP technology. Secondly, key parameters including anchorage cup length, thickness of bonding medium, number of wedges, pre-tightening ratio of wedges, and shape of grouting cup were selected for short-term static load tensile tests to investigate the influence of different parameters on the static load anchoring performance. Furthermore, a simulation model capable of accurately characterizing the performance of the 3D printing parallel composite anchorage was constructed based on the fundamental mechanical parameters of 3D printing CFRP. Results show that there are three failure modes of the anchorage system: tensile failure of bars, shear failure, and slip failure. The anchorage efficiency improves with the increase of anchorage cup length, pre-tightening ratio of wedges, and number of wedges. Specifically, the conical bonding medium exhibits higher anchoring efficiency compared to the cylindrical one. Under the combined conditions of a conical bonding medium, 100% pre-tightening ratio of wedges, anchorage cup length of 120 mm, and 3 wedges, the anchoring efficiency reaches 103.33%, which meets the standard requirements. This optimal configuration maintains structural integrity without failure. As the load increases, stress redistribution occurs at the CFRP bar-bonding medium interface. Additionally, the errors between experimental data and simulation results are controlled within 10%, and the trends are consistent, indicating that the constructed simulation model has a good strong predictive capability. In summary, the effectiveness of 3D printing homologous materials anchorage for the single CFRP bar is verified, which provides a theoretical basis and technical support for advancing the use of homologous materials in anchorages for CFRP bars.

     

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