The Dynamic Analysis Of The Fixed Crane's Supporting Cylinder Under The Condition Of Revolving System's Braking

The supporting cylinder of the fixed crane is one of the important loading parts when the crane works, its mechanical capability has direct influence to the normal operation of the whole machine. Do the static calculations for supporting Cylinder,the maximum loads that may occur in a variety of working conditions are taken into account ,the intensity and meet the need of design.the supporting cylinder's strength, stiffness meet the requirements. However, feedback from the ports indicates that in the conditions of a fixed crane's hoisting the cargo suddenly from the ground or suddenly unloading in the air, the revolving system and Luffing system's suddenly braking or jump-starting, the supporting cylinder will vibration obviously, with large amplitude. In the strength calculation, this distinct dynamic effect is replaced by safely coefficient. The treatment of transforming a complicated dynamic system into a simple and man-made static system can't reflect the essence of the problem accurately. In the analysis and calculation, the transforming the dynamic problem into a static problem is mainly due to the causation and influence factors of the dynamic loads' emergence is complex, and it is difficult to fit the dynamic loads. Aim at above problems, this paper takes the the GQ4525 fixed crane's supporting cylinder as a as an example, basing on finite element analysis and mechanical dynamics, Utilizing ANSYS10.0 to study the dynamic characteristics of the supporting cylinder and the the law of dynamic response.The main research is as follows:(1) Accodding to the configuration and working principle of the fixed crane, using the finite element analysis software ANSYS to establishs the mode of machine, and making the static analysis under the conditions of full loads.Combining with the crane structure theory to analyze the results.(2) Studying the dynamics characteristics of the fixed crane, making the modal analysis of the model, extracting the first 4 natural frequencies, vibration mode map and animation, and analyzing the results, evaluating whether the dynamic characteristics of structure meet the requirements.Determining the natural frequencies and corresponding vibration mode of the structure in the condition of revolving system's braking.(3) Combined with knowledge of mechanical dynamics, analyzing the causation and influence factors of the dynamic loads in the condition of revolving system's braking.Establishing the mechanical models from the different point of the body dynamics and structural dynamics. Analyzing the law of dynamic load, and fitting the specific function of dynamic load through theoretical calculations.Seeking the maximum dynamic load, comparing the results from two ways.Summarizing the approach of analyzing Dynamic load.(4) Making the transient dynamics analysis in the condition of the revolving system's braking.Accessing to the dynamic response results including simulation nephograms of dynamics stress and displacement and curve of dynamic stress of representative nodes.analyzing the results.Finally, attempting to optimize the structure.