The Mechanical Behavior Analysis Of Four-leg K-type Derrick And Its Substructure

At present, the main working K-type derricks are two-leg derricks, and there are fewfour-leg derricks are working. Many problems appeared during four-leg K-type derricksworking, so it's hard to use and popularize. Nevertheless, the mechanical behavior analysis offour-leg K-type derrick hasn't been studied deeply until now. Derrick rising is an unsafe process,the rising of four-leg K-type derricks is especially unsafe, and the stress state is complex ofderrick and its substructure during this process, however, the research data of derrick hoistingprocess were few. Because of this, the main content of the paper is to study the mechanicalbehavior of four-leg K-type derrick and its substructure, and the result will be compared withthe result of two-leg K-type derrick. This will be very important to derrick design and the safetyassessing theory.The finite element analysis model of the K-type derrick and its substructure is built bysoftware ANSYS. And the static mechanical analysis of the four-leg K-type derrick and itssubstructure and the two-leg K-type derrick and its substructure is done by the software whenthe derrick is working and when derrick is at each hoisting angles. The analysis result showsthat the stress state of the two kinds of derricks and their substructures is alike when the derrickis working, and the stress of the substructure of the four-leg K-type derrick is greater while thederrick is at each hoisting angles. The analysis shows that the stress of the substructure betweenthe two hinged supports of the derrick is greater, accordingly this works the distortion andavulsion of the substructure. In order to increase the intensity of the substructure, the suggestionis to weld steel plates between the two hinged supports of the derrick, as well as to increase thedimension of the hinged supports of the front two columns.Modal analysis is one kind of latter-day theory on dynamic characteristic research, and nowbecomes the core of dynamic analysis and design in modern engineering. Natural frequenciesand modes of vibration of structure resulted from modal analysis are the important parameterson dynamic design of structure. So it is the start of all dynamic analysis, transient analysisspecially. The modal analysis of the two kinds of derrick is done when the derrick is workingand the derrick is at each hoisting angles. And the transient dynamics analysis of theJJ162/42-K type derrick is done, and the transient response characteristic of the derrick isgained.