Comparative Study Of Pump Truck Finite Element Multiple Unit Calculation

Concrete pump trucks are one of the widely used mechanical equipments in the modern engineering construction field the design of cantilever crane and the strength properties study of concrete pump trucks are heat and numerous in mainland and overseas. For the model established in finite element analysis software, most researchers select the shell element of finite element to simulate the cantilever cranes and cantilever plates, and the solid element of finite element is also considered. Taking a37m boom truck for the study, using the finite element calculation of solid and shell elements to compare, and Get more conducive to engineering applications of finite element modeling.The main research content are as follows:1. Select the level of the boom fully extended condition, the use of solid and shell elements to establish two ANSYS finite element model.2. Select multiple thin-walled cantilever model which has the same length, different cross-sectional dimensions and thickness for the experimental stress test, and establish the ANSYS finite element model by solid and shell elements for each cantilever o Finite element calculations results and experimental results show that, under the same conditions finite element shell element calculation result is smaller than the solid element calculations, and smaller than the measured stress either.solid element is more suitable than shell element on finite element stress calculations for thin cantilever arm.For a variety of thickness-width cantilever beam, the stress was calculated by using several kinds of elements including shell63,shell181and solid45entity unit, the maximum tensile principal stress and the relative error were comparative analyzed. For the same thickness cantilever beam, The relative error calculated by shell element and solid element on the top surface along the center line is approximately constant For a square structure cantilever beam, The relative error of principal stress calculated by shell element connected with thickness-width ratio only, the smaller the thickness-width ratio, the smaller the relative error. 3. Calculate the load pattern including concrete pipes with internal concrete weight、rotary inertia force, wind load and ends traction, compare the Tresca theory、Mises theory and limiting strain energy strength theory maximum of each component for finite element solid element and shell element, found that the calculated value of shell elements to be smaller than the solid elements, If the arm strength calculation using the finite element shell elements, will reduce the actual design of the safety factor.The equivalent stress based on different strength theory in the same principal stress state varies widely In different principal stress state, there exist security risks for which is conservative to structural strength design based on MISES theory. ANSYS finite element does not distinguish between principal stress states for its output of equivalent stress, which is not appropriate that there is Mises equivalent stress only. Full total figures65, tables26, references59...