Simulation study of fracturing pump connecting rod big end bearing wear failure based on multi-body dynamics

Fracturing pump is the core equipment in fracturing operations. Facing the process characteristics of shale gas fracturing operations, such as ultra-high pressure, large displacement, variable working conditions and long period, the key components of fracturing pump are prone to failure due to almost full load and non-intermittent operation. In this paper, a new type of five-cylinder fracturing pump is taken as the research object, and the vibration response of the fracturing pump under the corresponding failure modes is investigated. A rigid-flexible coupled dynamics simulation model of a new five-cylinder fracturing pump with typical failures of the key components is established by combining the multi-body system dynamics and the L-N nonlinear spring-damped contact force model. The vibration response of the pump is then investigated. The vibration response of the fracturing pump unit under no-load conditions with typical failures of the connecting rod and big end bearing is also investigated, as well as the data of the failure characteristics, which provide a theoretical basis for the understanding and prediction of the vibration behaviors of fracturing pumps under failure conditions. This study provides a theoretical basis for the fault diagnosis and health monitoring of fracturing pumps, enhancing their reliability and safety in practical engineering. Furthermore, it serves as an important reference for the fault diagnosis and prediction of reciprocating mechanical equipment.