履带起重机主臂风场流固耦合分析

Fluid-structure coupling analysis of wind field of crawler crane main boom

文中合理简化QUY220型履带起重机桁架臂主臂模型,建立主臂结构的流体风场模型和固体计算模型,选择78.16°变幅和吊载130.6 t工况进行分析,得到了流体风场主臂结构的表面压力和速度。利用Workbench将表面压力、速度等参数传递到固体计算模型中,实现主臂结构的单向流固耦合数值分析,提取位移,应力等参数,研究15.5 m/s、28.3 m/s、55 m/s的风载荷对主臂的影响。依据理论和起重机设计规范计算主臂表面的风压和流速,将计算结果与CFX模拟的结果进行比较,发现相对误差最大为0.019873,可用此方法来模拟桁架臂主臂不同风速下的风压,进行更准确的桁架臂主臂结构设计。起重机在不大于28.3 m/s风速下作业,由风速引起的位移占比较小,偏于安全。非工作状态下,随着风速增高由风速引起的位移在总位移中占比提升较快。风速引起的倾覆力矩逐渐增大。在设计桁架臂主臂时应该考虑顺风向风载荷对整机倾覆的影响以及横风向对主臂稳定性的影响。

The main boom model of the truss boom of QUY220 crawler cranes was reasonably simplified,and the fluid wind field model and solid calculation model of the main boom structure were established.The surface pressure and velocity of the main boom structure in the fluid wind field were obtained by selecting 78.16 amplitude and lifting load of 130.6 t for analysis.Through Workbench,the surface pressure,velocity and other parameters were send to the solid calculation model,the unidirectional fluid-solid coupling numerical analysis of the main boom structure was carried out,and with extracted displacement,stress and other parameters,the effects of wind loads of 15.5 m/s,28.3 m/s and 55 m/s on the main boom were studied respectively.According to the theories and design specifications of cranes,the wind pressure and velocity on the surface of the main boom were calculated,and calculated results were compared with those simulated by CFX.It was found that the maximum relative error was 0.019873,indicating that this method can be used to simulate the wind pressure of the main boom of the truss boom under different wind speeds,so as to obtain more accurate structural design of the main boom of the truss boom.When the wind speed is not more than 28.3 m/s,the displacement caused by wind speed is relatively small,so the crane is safer.In the non-operating state,with the increase of wind speed,the displacement caused by wind speed increases rapidly in the total displacement,and the overturning moment caused by wind speed increases gradually.In the design of the main boom of truss boom,the influence of downwind load on the overturning of the whole machine and the influence of crosswind load on the stability of the main boom shall be considered.