Structure Analysis And Improvement For Variable Amplitud Hydraulic Cylinder Of A Type Of Concrete Pump Truck

Concrete pump truck is a kind of large construction machinery with the functions of pumping,distributing and walking.Due to the bad working environment and long working cycle of the boom,the variable amplitude hydraulic cylinder has higher requirements.The performance of the variable amplitude hydraulic cylinder will affect the working performance of the boom,thus affecting the working reliability of the whole machine.Due to its irregular structural geometry,it is difficult to establish an accurate analytical theoretical calculation model and fatigue life prediction model.In order to improve the reliability and economy of hydraulic cylinder design,this paper intends to complete the structural optimization and fatigue life prediction of hydraulic cylinder by establishing an accurate parametric finite element overall model of hydraulic cylinder.This paper takes the variable amplitude hydraulic cylinder of a certain type of pump truck as the research object.Firstly,the circumferential normal stress of cylinder and axial stress of piston rod are calculated theoretically according to the load spectrum.Secondly,the parametric finite element model of the variable-amplitude hydraulic cylinder is established with the APDL language of ANSYS,and the static analysis of typical working conditions is carried out to obtain the stress distribution and displacement cloud diagram of each key component.The buckling analysis of the variable amplitude hydraulic cylinder under full extension condition is carried out and the critical buckling load is obtained.The circumferential normal stress of cylinder and axial stress of piston rod were extracted and compared with the theoretical value.At the same time,the stress test results are consistent with the finite element analysis results.Then,based on the nominal stress method,the fatigue analysis of the variable-amplitude hydraulic cylinder is carried out,and the fatigue life distribution of each component is predicted.Finally,with the goal of lightweight,the variable-amplitude hydraulic cylinder is improved to achieve a weight reduction of 9.1%.The improved structure meets the requirements of strength and stability,providing theoretical guidance for the structural improvement of a series of variable-amplitude hydraulic cylinders for the pump truck.