露天潜孔钻机钻架-平台耦合振动特性分析

Analysis on Coupling Vibration Characteristics of Drilling Frame-Platform Structure for Open-pit Down-the-hole Drill

潜孔钻机在大风环境下工作受周期性冲击载荷和风载荷共同作用,动力学行为与钻架和平台结构耦合振动特性密切相关,直接影响钻机工作可靠性.对国产某型潜孔钻机进行改进设计,建立钻架-平台结构耦合动力学模型,采用ANSYS软件对周期性冲击载荷与平行风载（与车身方向平行）或正交风载（与车身方向正交）联合作用下结构耦合振动特性进行仿真分析.结果表明：耦合振动的前十阶模态频率分布在3-28Hz范围内,在14.46-25.32Hz之间存在一个较宽的模态间隔频带,位移幅频特性和动应力幅频特性均存在一个低幅响应区.风载荷相对于机身的作用方向对幅频特性影响很大.该钻机在平行风载下钻架顶端观察点振动位移幅明显低于正交风载下振动位移幅.平行风向载荷下钻机结构最大动应力幅值低于正交风向载荷下钻机结构最大动应力幅值.钻架-平台结构耦合振动特性为钻机结构动态优化设计提供理论依据.

Down-the-hole（ DTH） drill was affected by periodic impact load and wind load while working in strong winds. The dynamic behavior was closely related to coupling vibration characteristics of drilling frame-platform structure. This directly affected the reliability of drilling rig. For a domestic type of DTH drill,improved structure,the coupling dynamics model was constructed. By ANSYS,the coupling vibration characteristics were studied under the combination of cyclical impact load and parallel wind load（ parallel to rig body） or the orthogonal wind load（ orthogonal to rig body）. The results show that the first ten order modal frequencies of coupling vibration are within 3 - 28 Hz,a wide modal frequency interval is between 14. 46 Hz and 25. 32 Hz. The displacement amplitude-frequency and the dynamic stress amplitude-frequency have low response domain. The wind load direction has a significant influence on amplitude-frequency characteristics. For the observation point at the top of drilling frame,displacement amplitudes under parallel wind load are significantly lower than under orthogonal wind load. The maximum dynamic stress under parallel wind load is lower,compared with under orthogonal wind load. These coupling vibration characteristics provide theoretical basis for DTH drill structure dynamic optimization design.