Welding Seam Measurement System Of Large Thin-walled Cylinder Structures

Friction stir welding which is a new kind of solid phase welding method has all kinds of advantages such as good mechanical properties,low cost,high efficiency,non-pollution and wide applications.In view of its advantages, the process stability and the welding quality can be improved by using FSW to weld the rocket tank compared with TIG method.The assembly accuracy must be good in order to guarantee the welding quality.Therefore,it’s necessary to measure the welding seam including height difference and gap before the welding of the rocket tank to make sure whether the welding seam is qualified or not.Large aluminum components such as rocket tank have a large diameter and thin thickness,which leads to a lower rigidity. The welding seam should be measured online before FSW.It should be sure that the measurement results can correspond to position.Then the welding seam in unqualified position should be adjusted until it is qualified,which can ensure good assembly and welding qualify.In this paper,a welding seam measurement system is developed based on hardware equipments and LabVIEW according to the engineering application.In the system the welding seam is measured with the method of laser vision sense which has many advantages.The height difference and gap of welding seam can be measured in the system.What’s more,the measurement results can correspond to position and it can alarm in unqualified position.The system functions can achieve in the experiment.Finally a welding seam adjustment device which can hold up the rocket tank and adjust it is designed,simulated and analyzed in Autodesk Inventor.The experiment result shows that the welding seam measurement system which can complete the measurement task well has some practicality in application.The Stress and strain of the welding seam adjustment device is qualified.