| With the accelerating pace of China's urban construction, as well as the substantial using of commercial concrete, the truck-mounted concrete pump has becoming an indispensable construction machinery in the architectural industry. Boom structure is a key factor in pump design and manufacture, boom structure which is reasonable or not will directly affect vehicle working-performance. It's very necessary of finite element analysis for the boom structure.This paper uses the various types of finite element modules, through Pump's Boom System modeling, strength calculation and modal analysis of the boom, combined with static and dynamic tests to verify the accuracy of the finite element method and modify the load, and finally, through the parameter computation program of Boom, we calculate many conditions of the finite element method for the boom, as follows:1 Boom linear and nonlinear calculationBuilding the finite element model of the concrete pump truck, under constraints and loaded, we calculate the static conditions of linear and nonlinear geometric large deformation, when the boom at full-stretch level. Through linear and non-linear calculation results contrast, analysis, we master the conditions of the deformation and stress distribution of the boom structure, which is at the most dangerous operation, to know well that the various components of the stress concentration regions and the structure of weak parts, forming a set of computation method, which is the systematic based on ANSYS software platform for the Pump's Boom, completed to compile the Boom parameter computation program, and finally, we will provide a strong theoretical basis for the serialization of Pump's Boom design and product design.2 Boom system vibration analysisWhen pouring concrete, the hydraulic tank pushing the boom extension is in a locked status, at this time, the boom system will have elastic deformation under the impact of the concrete, the external manifestation is boom vibration. From the finite element theory, the structure of the natural frequency is plenty, but the impact of structural properties is only a few ahead. Modal analysis is the calculation of the structure of its own natural frequency and corresponding vibration mode, nothing to do with the load, so only considered the various parts of the mass distribution to carry out modal analysis. we extract the pre-six order's natural frequencies and vibration mode, compared and evaluated the calculation results for putting forward a improvement rationalization proposals to improvement structural.3 Boom system strain testThe boom structural strain test is to use static and dynamic electric measurement method, that is, affixed the strain gauges, which is selected test points on the location of the Boom to carry out different working conditions strain test, surveying these points' particular direction stress at the operating condition, sorting the dynamic, static state and finite element stress value, and through dynamic strain test curve to sort boom Lifting and rotary impact factors. Finally, through comparing the absolute error and relative error of the dynamic and static stress test value and calculated value,the accuracy of the finite element method results is verified and the load is modified.4 Boom system many cases calculationMost previous research on the concrete pump boom just carry out one or several cases for static analysis, to some certain extent, this analysis does not fully be able to explain the case of boom force and stress during the process of the boom working. Therefore, realizing many cases for static strength calculation, extraction and analysis of the results' data, thus, we get the boom's changes and distribution regular, which for the boom system to improve the design and in-depth meticulous study on the dynamic characteristics of the system provide a theoretical basis, but also for other types of boom systems, as well as a similar structure to provide a reference method of the calculation of analytical.
|
PDF Full Text Request