The Vibration Analysis And Control Of Concrete Pump Truck Boom

Concrete pump truck is an important engineering machinery in the constructionindustry. It has features such as high efficiency, convenient use, pouring work quickly.Today, the figure of concrete pump truck more and more appear in people’s eyes. Themain purpose of the concrete pump truck is pumping concrete from low to high place inthe engineering construction, reducing the labor intensity at the same time. The mainstructure of concrete pump truck is made by the folding boom, hydraulic pumpingmechanism, concrete hopper and other major equipment installed in the heavy-dutyvehicle chassis. Through the associated electrical control system, the equipment structurescan be closely linked together and work together. Made the hydraulic pump can absorband pump to achieve the purpose of continuous pumping concrete.With the improvement of requirements for pumping concrete, some problems ofconcrete pump truck also gradually appeared in front of people. When pouring somecolumn construction, Vibration of booms might make the precision of casting is not up tothe requirements. This is a problem of concrete pump truck have long been concerned.Reduce the concrete pump truck boom vibration not only can improve the concreteplacement accuracy, but also can avoid the boom failure problem caused by the long termvibration. Therefore, the research for the concrete pump truck boom vibration haspractical application value.In this paper, starting from the understanding of the working principle of concretepump, grasp the relationship between each system. First of all, introduced the workingprinciple of the hydraulic system, analysis on positive pump, the alternating of twoconcrete cylinder push process and conversion process between six directional controlvalves, Find one of the arm frame vibration excitation source which is the hydraulicimpact phenomenon. Further analysis indicates that the hydraulic impact is mainlycomposed of delay suppress oil pressure and reversing hydraulic impact of two parts.Then detailed introduces the principle of concrete in the flow of the transporting pipe, Understand the flow of concrete can use bingham model to explain in the field ofrheology and find another boom vibration excitation source for the flow of concrete on theimpact of the transporting pipe. Through further analysis indicates that the flow of theconcrete impact is mainly composed of friction impact and concrete flow change impact.Finally, analyze the reason of the above two kinds of excitation source, master parametersrelate to the excitation source, calculate excitation source value.Establish finite element model of concrete pump truck. According to the Pro/Emodel of concrete pump truck boom, simplify the parts of boom structure, establish thefinite element model of the boom by the Hypermesh software. The arms are assembledtogether according to the analysis of working condition of boom, apply loads andconstraints. Adopt the Nastran finite element software to simulate calculation. Calculatethe different response value in two kinds incentives, analyse the parameters of theincentive and dynamic stress of the boom. Propose solutions to reduce boom vibration.According to the proposed scheme, change the structure of the relevant parameters andthe excitation parameters of the boom, calculate excitation source value, apply loads andconstraints. Simulation analysis calculated by Nastran finite element software Again, Toverify the feasibility of the proposed scheme to reduce the vibration of boom bycomparing the two simulation results before and after improvement.Through the practical analysis, this article concluded as follows：1) Hydraulic impact is mainly composed of delay suppress oil pressure and reversinghydraulic impact. Reduce the size of the hydraulic impact peak (reduce the amount of oilpump) can reduce vibration displacement amplitude of the end of boom. In the case ofreducing hydraulic impact peak. The response amplitude of horizontal condition change isgreater than bending condition.2) The flowing concrete impact is mainly composed of friction impact and concreteflow change impact. The vibration of bending condition is mainly caused by the frictionimpact, the vibration of horizontal condition is mainly caused by concrete flow change impact. Strengthen the thickness of the steel plate where the stress is larger can effectivelyreduce vibration displacement response at the end of boom.3) Hydraulic impact and flowing concrete impact which are two kinds of concretepump truck vibration excitation source can cause vibration of the boom, The vibrationamplitude caused by the hydraulic impact is less than the flowing concrete impact. Themain vibration excitation source is the transporting pipe flow concrete impact.