Mechanical Characteristics And Reliability Analysis Of Concrete Pump Boom

Concrete pump truck is a special vehicle for conveying concrete.It is widely used in the construction industry because of its pouring evenly,quickly and efficiently,constructing safely.The core part of the pump truck is the boom,by which concrete will be poured to the proper location.In order to ensure that no fracture accident occurs to the boom during construction,the most dangerous working condition under stress in boom construction is selected for research,which not only ensures the safety under other working conditions,but also verifies the rationality of structural design,providing further reference for the optimization of structure.In this paper,two dangerous working conditions of boom deployment are selected for research,and the mechanical properties and structural reliability of boom are analyzed.The main tasks are as follows:(1)Selecting the dangerous working condition of boom horizontal expansion,discuss the main load type of boom and simplify equivalent treatment.The 3d model of the boom drawn by Solid works was imported into Workbench through seamless linking technology,and the finite element model of the boom was established.The maximum displacement and stress of the boom is obtained by static analysis,and the stiffness and strength requirements of arm frame are verified after analysis.(2)Studying the dynamic response of the boom under the dangerous condition of horizontal expansion.Firstly,the modal analysis are carried out,in this step,we can obtain the natural frequencies and modal shapes of the boom,and put forward to a suggestion that can prevent the vibration of the boom from causing resonance due to the close working frequency of the piston pump.Further harmonic response analysis is carried out to obtain the end displacement and frequency response curves of the boom,and the displacement and stress changes of the lower boom with three peak frequencies are analyzed.(3)To ensuring the working stability of the boom,buckling analysis were carried out under the vertical working condition,after that can obtain the buckling eigenvalue and buckling mode shapes of the boom,and calculate the critical load.In order to prevent the tipping accident caused by the weight of the boom and the weight of the concrete in the loading pipe,the stability of the boom under dangerous working conditions was studied.By calculating the ratio of stabilizing moment and tipping moment,it was proved that this pump truck has certain ability to resist tipping.(4)The parameterized model of the first boom was established in Mechanical APDL.Under the condition of 95% confidence level,the structure reliability analysis was carried out with PDS module.The reliability of displacement and stress of the arm frame was obtained by the method of Monte Carlo.The design parameters affecting the displacement and stress of the boom are found out by sensitivity analysis.Two sets of correlation parameters were selected and the response surfaces of boom displacement and stress were obtained by the response surface method.