Axial Vibration Characterization Analysis of Drilling Rig’s Drilling-String System with ABAQUS and MATLAB Co-Simulation

Complex geological layers lead to unstable drilling quality and frequent drilling string failures in pile foundation construction. To address this, this paper studied the axial vibration characteristics of the drill-string system in miniature steel-pipe-pile rigs under both hydraulic propulsion and drilling bit rotation. Based on the law of energy conservation and the Lagrange equation, a dynamic model of the drilling-string system’s axial vibration was established, and the corresponding simulation model was built using MATLAB. ABAQUS was used to simulate and analyze the response process of drilling granite, and the accuracy of the theoretical model was verified by ABAQUS–MATLAB co-simulation. Through a series of system responses, the axial reaction force increased with the propulsion load under the fixed angular velocity. This increase exhibited obvious nonlinear characteristics. Otherwise, the fluctuation of the axial reaction force is primarily influenced by the mechanical rotational speed. Through the time domain response analysis, the displacement of the drilling bit showed a strong positive correlation with the hydraulic propulsion load. The contact process between the drilling bit and rock showed unstable and stable regions, and the amplitude of the system response fluctuated a lot at the early stage of the contact. The amplitude of vibration displacement between drilling strings showed a decreasing trend. Frequency domain analysis indicated that higher rotational speeds enhanced system stability by primarily suppressing the large-amplitude vibration at the fundamental frequency. This study provides a theoretical basis for the design and operation optimization of the miniature steel-pipe-pile drilling rig, and provides a new perspective for the development of the vibration control technology of the drilling-string system.