桥梁缆索热铸锚不同灌锚工艺的数值分析

Numerical analysis of different casting processes for hot-cast anchors of bridge cables

桥梁缆索热铸锚灌锚方法对铸体密实度和锚具锚固性能有重要影响。以Φ7 mm-187-2100 MPa斜拉索锚具和Φ5 mm-127-2200 MPa悬索桥主缆索股锚具为例,采用铸件充型凝固过程数值模拟技术,研究了不同灌锚方法和工艺参数对合金铸体缩孔缩松情况的影响。结果表明,采用水平灌锚法、浇铸模具上设置与浇口分离的顶冒口、合金浇铸温度为450℃、模具预热温度为250℃、合金充型凝固过程中对模具大端上半部分加热至390℃以上并持续12 min,可有效提高铸体密实度。

The alloy casting methods of hot-cast anchors for bridge cables have a significant impact on the compactness of the casting body and the anchorage performance of the anchors.Numerical simulation of casting flling and solidification process is employed to study the influence of different casting methods and process parameters on the shrinkage and loosening of alloy casting bodies.The study focuses on two types of cable anchors,that is,theФ7 mm-187-2100 MPa cable anchors of cable-stayed bridges and theΦ5 mm-127-2200 MPa anchors of main cable strands of suspension bridges.The findings clearly show that the horizontal casting method,setting the top riser separately from the gate on the casting mould,maintaining the alloy casting temperature at 450°C,preheating the mould to 250°C,and heating the upper large end of the mould to a temperature exceeding 390°C for 12 minutes during alloy filling and solidification,are the most effective ways to enhance the compactness of the casting body.The analytical results provide unquestionable theoretical and technical support for the design and fabrication of hot-cast anchors of bridge cables.