旋挖钻机桅杆瞬态动力学与疲劳研究

Transient dynamics and fatigue analysis of the mast of rotary drilling rig

为了得到旋挖钻机入岩时桅杆的疲劳寿命与切削深度之间的变化规律,根据短螺旋钻头入岩的理论,建立旋挖钻机钻头入岩时载荷的数学模型,针对组合岩石,模拟短螺旋钻头的工作载荷,然后将得到的载荷应用到桅杆的瞬态动力学响应分析中,确定随机载荷作用下桅杆的危险部位.利用Miner线性疲劳损伤理论,计算得到桅杆危险部位的疲劳寿命.结果表明:在旋挖钻机入岩时的切削深度允许范围内,桅杆危险部位的疲劳寿命随着切削深度的减小而增大,且切削深度减小的幅度相同时,桅杆危险部位疲劳寿命增加幅度的逐渐增大.

In order to get the change rules of the fatigue life of mast and the cutting thickness when the rotary drilling rig digs into rock,this paper establishes the mathematical model of loads for the drill bit based on the theory of short auger bit into the rock,which simulates the load of short auger bit into the composite rock in MATLAB,then applies the obtained load to the analysis of the transient dynamic response of the masts,and obtains the stress of a node of mast.The fatigue life of mast is calculated with Miner fatigue damage theory.The results show:in the range of cutting thickness,the stress of the mast increases with the decrease of cutting thickness.And with the same decreasing amplitude in cutting thickness,the stress on the mast decreases gradually.