Design Method And Analysis Of Pipelayer Structures And Balance

Pipelayers are special construction equipment for laying oil and natural gas pipelines, and widely used for transportation and fitting of the pipelines. Pipelayers play an important role in constructing transport network of pipelines. With the development of oil and natural gas industries, the application and market demand of pipelayers is increasing.The 70 tons crawler pipelayer is capable of lifting a rated weight of 70 tons in the given range. This means that the pipelayer boom can bear the weight of 70 tons. If the boom strength is not satisfied to the specific requirements, the boom will be broken. Because the boom structure is complex and irregular, in general, ordinary solution methods are no longer applicable to deal with the real engineering structural problem. Numerical simulation and analysis for the boom structures are used by ANSYS software to improve the strength performance of the boom structure according to the stress distributions and actual working conditions, and let the boom meet the strength requirements.The pipelayer is often employed to complete lifting operations by its hoisting mechanism. Vibrations are produced in the process. If the boom is excited to behave resonant vibrations by the motion mechanism, the boom structure will be seriously damaged. In order to prevent the boom from resonance with the motion mechanism, the modal analyses of the boom structure are also carried out by ANSYS software. Simulate the natural frequencies and vibration modes of the lift mechanism which may let the boom vibration in the actual working conditions. By the numerical predictions, it is confirmed that the boom is avoided from resonant vibrations in the working states.A counterweight of the pipelayer must be provided on the other side opposite to the direction of the lifting boom to strike a balance during lifting. In order to prevent the pipelayer from tipping to the boom while lifting in one hand and to the counterweight while unloading in the other hand, the stability of the pipelayer is studied by using the mathematical model and dynamic simulation in ProE software. The optimal position of the main hinge point is solved by MATLAB software and then implied the pipelayer stability requirements are satisfied in the initial state. The stability of the pipelayer will improve and the pipelayer weight will reduce by using the optimal hinge position, but it is not obvious to improve the pipelayer’s center of gravity without loading.After completion of the pipelayer prototype manufacture, tests and measures are made for validation of the pipelayer performances.