| The all terrain crane has got rapid development for the market demands in China from the21st century. Tonnage has reached thousand tons, and main boom lifting height reaches more than hundred meters. The application of guying device has played an important role, which is installed on the main boom, connecting the head and tail. The guying device composites the space secondary statically indeterminate structure with the main boom. It improves the stress of the boom, reduces the boom head deflection, and improves the lifting weight. But because of the complexity of the guying system technology, the guying performance on the crane of domestic enterprises is not into full play. There are many factors deciding the guying performance, such as, guying device installation location, guying opening angle, the length of the guying frame, these factors have been studied maturely in many years of application. However the most key factor guy-rope preload calculation has not yet applied maturely, there is almost no relevant research literature, so further study is needed.Now when involving guy-rope calculation, the geometric nonlinear characteristics of the guy-rope is not considered. So the precision of large deformation analysis of boom system with guying system needs to be improved. This paper, on the basis of considering the flexible guy-rope, puts forward a fast simple calculation method for the preloaded guy-rope, providing reference role for later design. Main work content is as follows:(1) According to the mechanical properties of the boom system on the all terrain crane, nonlinear influence factors are analyzed. One of the biggest nonlinear effects is guy-rope, so its nonlinear numerical simulation method is emphasized. At the same time the boom simplified model creation method is established, using this method to establish model, compare and analyze the result difference of eigenvalue buckling and nonlinear buckling.(2) The establishment of preloaded guy-rope calculation method and its parameters. This paper establishes a set of calculation method which makes guy-rope length as a variable, takes the main boom stress and the boom overall stability as the evaluation criterion, to analyze and research the influence that guy-rope length changes on the boom lifting performance. Combined the APDL language of ANSYS with MATLAB platform, the calculation method is programmed into software, realizing the parameterized input and automatic calculation.(3) The relationship between pretightening angle-force with the guy-rope length is discussed. Quantitative analysis by examples is done to study the influence of the guy-rope length changes on the lifting performance of boom, thus finding out the optimal length of the guy-rope corresponding to each boom length. And then the pretightening angle and pretightening force can be calculated.In this paper, research results provide an effective calculation method of the preloaded guy-rope for the design of the all terrain crane guying system, which can quickly and accurately determine the optimal length of the guy-rope corresponding to each boom length. It provides certain theoretical basis for the design of the working condition of crane with guying system. |
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