Mechanical Analysis Of 'A' Form Derrick's Failure

An oil derrick is a necessary supporting frame, and plays an important role in oil production.'A'form derrick, whose biggest carrying capacity is closely paid attention by the workers, is in extensive use. Nowadays, the evaluation theory and the techniques, inland or foreign, about the bearing of the derricks used in wells drilling, can't satisfy the testing requirement of the derrick's bearing capacity. So, it is necessary to research into the accepted load of the derrick and the theory of it's out of work. From the mechanical angle, this thesis analyzed the'A'form derrick's bearing endurance, the entire stability and the dynamics problems in derrick telescoping, established the dynamics module of the derrick'structure, analyzed the module by using finite element method and calculated it's maximal bearing capacity. From the security angle, the referred ideas of derrick's design and the maintenance plans were given, and, a set of theory, which can guide the working site security of the job implementation and operating, through finding out the weak point causing deformed of the derrick and analyzing it from the materials and the architecture.In this paper, the computations and treatments provide reference for the evaluation of the'A'form derrick'bearing capacity, derrick'design and maintenance plan.