Vibratory Research And Dynamic Design Of Rig Substructure

In our country, rig substructure is designed mostly on the basis of its static strength and designer's experience, and its dynamic characteristic is usually taken no account. As a result, the rig substructure vibrates violently when its nature frequencies close or equal to the working frequencies of the drilling equipment, which deteriorates the substructure's working status, shortens its lifetime and makes the working process dangerous. Thus, it's necessary to improve the design of rig substructure or better the dynamic characteristic of substructure that is being used by dynamic modification.But, different kind of rigs have different substructure styles, and the rigs of same kind have different substructure frameworks, too. A lot of tests are required if the dynamic characteristic of the substructure is to be known and used. But it's very difficult to proceed lots of tests because of the restriction of field environment, and the influence of atrocious environment on testing can depress the precision and reliability of results. The disadvantageous factors mentioned above can be avoided by simulation tests in lab on model.In the experimentation, through analyzing the frame and vibration of substructure, the author ascertain the experiment project of the substructure vibration test which dependents on vibration status at present and trial equipment in existence, the experiment is divided into three groups according as the stimulation's direction, which are cross direction horizontally, longitudinal direction horizontally and direction perpendicularly, and dispose stimulation drop on the mode.Based on the DASLab analysis platform, mass parallel real-time Acquisition Analysis System having 46 channels was developed for dynamic signal, according to analyzing transfer function analysis, modal analysis, power spectrum analysis, we can get some data about mode, which was important evidence to afterward FEA analysis. In the vibration analysis for substructure, firstly AlgorFEAS was developed. After it, by adopting the three-dimensional beam element as the basis element for FEA analysis of substructure structure, the author established the computer numerical model to analyze the mechanical parameters about model. In the measure analysis for substructure.Based the foregoing work, combining measure and FEAS analysis for substructure, this thesis get the characteristic vibration. For the FEAS, the author presented an theory of matrix spectrograph to modify the model of FEA, so as to the real structure of substructure in use, and then through computer loading simulation test to get the vibratility, and carry through the dynamic design. When the design carried through, according to some things that affect rig substructure's vibration, The author tries out modification test to the FEA model, and analyzes the new dynamic figure, so we can know the change thing of rig substructure and get the significative conclusion to the substructure.