Abstract: Accurately evaluating the vibration characteristics of fracturing pump units plays a crucial role in enhancing the safety of offshore fracturing operations. This study established a refined numerical model of the fracturing cabin coupling system based on a vibration characteristic test on a single fracturing skid, and focused on simulating and analysing combined vibrations under multiple working conditions. Parameters considered include the number of activated fracturing pump, spatial layout, and load frequency, et. al. The research results indicate that the static response accounts for more than 80.0% of the total response, while the dynamic response contributes less than 20.0%. The vibration of the fracturing pump attenuates along the deck in a sinusoidal half-wave pattern, with a peak amplification effect of 2.0~2.5 times observed at the activated pump. As the number of activated fracturing pumps increases from 1 to 5, the maximum dynamic response generally shows an upward trend, with peak displacement increasing by 57.5%, peak acceleration by 6.5%, and peak stress by 5.1%. A five-level startup strategy for fracturing pumps was proposed, specifically starting from the edge toward the centre. When the bidirectional inclination angle increases from the baseline state (0°) to the critical threshold, the peak displacement increases by 190.0%, the peak acceleration increases by 141.0%, and the peak stresses on the three core components, i.e., deck, deck beam, and connection base, increase by 20.0%, 22.0%, and 21.0%, respectively. The failure mode of the coupling system manifests as the overall strength failure of the deck, with the failure morphology highly consistent with the modal shape.

Key words: integrated fracturing operation vessels, fracturing pump units, vibration characteristics, vibration propagation, numerical simulation, multi-working-condition analysis