The Finite Element Analysis In Multi-condition And Research On Dynamic Simulation For The Boom System Of The Truck-moundted Concrete Pump

With the accelerated pace of city and the increasing investment of country in infrastructure construction, the concrete pump is more and more widely used, plays an increasingly important role and has become one of the indispensable equipments in construction industry, due to its maneuverability, agility and high speed of pouring.Boom system is the core part of the concrete pump, through the study of it in static and dynamics, the disciplines of variation in its intensity and stiffness,which can be helpful in design and optimization of the boom system and product promotion of the concrete pump in turn, are got. In this paper, the boom system is systematically analyzed and researched, based on the finite element theory and multi-body dynamic simulation technique.The finite element model of the boom system of the HB52 concrete pump is got by dealing with its existing geometry. In this process, the appropriate element types and the correct finite element information are very important. After the models of all parts are established, each of them is assembled by using the APDL language of ANSYS. During the assemble, because the position of each rod changes in different conditions with combinations of angles between each boom, the coordinates of hinge points of the rods in its different connecting styles are calculated, and then the macro files corresponding to this are made for the convenience of procedural call.In the boom system model completed, through the VB language structured the software interface and framework, combined with ANSYS parametric language and the computer batch command, compose the concrete pump truck boom system calculation program with multiple loading conditions, which is the BOOM program. the BOOM program can use to automatically call the ANSYS classic interface for any conditions finite element analysis of the boom, or call the ANSYS batch commands and back-calculation program for the batch calculating of multiple loading conditions. Type of finite element analysis involves the calculation of the linear static, nonlinear static analysis and modal calculations.Application with the BOOM program for the boom system's linear and nonlinear analysis, by comparing the results of the calculation, we can master the boom's Stress distribution condition under the maximum stress case, understand the structure's stress concentration regions and the weak parts, Optimizing for boom to provide a reference value in the next step. After the static analysis, we apply the BOOM program on modal analysis for the boom Structure, through calculating we get the boom Structure's natural frequencies and corresponding mode shapes, and extract the first six natural frequencies and mode shapes in the level of risk conditions, Compared and evaluated the results, put forward rationalization proposals for the Structure improvement.In order to verify the accuracy of FEA result, the boom structure stress test is needed. After determined the test purposes and scheme, the boom structure stress test was finished through the test system Composed by the dynamic testing equipment and strain gauges. The relative deviation and absolute deviation of the test and calculated value were obtained. After comparative analysis, the deviation between the test results and calculation results is Small, which illustrates the accuracy of finite element analysis. The finite element structural analysis can provide a good reference.The dynamic simulation of boom system is preliminarily researched with ADAMS, a dynamic simulation software. Through assembling the three-dimensional geometric models with the ADAMS command language and imposing restrictions and motions on the corresponding hinge points and cylinders, the rigid model of the boom system is established. The simulation can get the motion curves and force curves at the hinge points in the post-processing module. After the rigid model simulation, transfer the rigid bodies to flexible bodies, establish the rigid-flexible hybrid model, and then do the dynamic simulation. The rigid-flexible hybrid model can well simulate the actual movement of the boom, but the establishment of the model is complexity and the simulation process is time-consuming. In summary, the calculation and analysis of the boom system, which is based on the finite element analysis and multi-condition calculation program, can be reference for the further design and optimization of the boom structure. Then the dynamic simulation of the boom system is preliminarily researched. The movement and force of the boom system, during the simulation of its actual process, can be analyzed. All of these can be reference for the development and design of the product, and the improvement of its performance.