Research On The Behaviors And Quality Control Of Resistance Spot Welding Of Aluminum

RSW(Resistance Spot Welding)is widely used in modern manufacturing industryespecially in areas of aerospace and vehicle. Welding process which is influenced by manyuncertain factors is non-linear and complex. Nugget formation is invisible and weld time isvery short which brought great difficulties to get information on weld quality. There is noeffective methods for on-line quality monitoring. Much work have been done by weldingscholars home and abroad and some advance has been made.First of all,this paper introduced the present research situation of resistance spot weldingquality control by scholars home and abroad, and what can be derived is that complex factorsmust be considered in order to monitor and control the quality of spot welding. Dynamic datarelated to the formation of welding spot is collected, including welding current,electrodepressure and electrode displacement. The quality information of welding nugget is recorded,because the dynamic data can reveal the entire course of formation of welding nugget. Thenthe dynamic welding data are compared and analyzed by plenty of experiments for thecharacteristics which can indicate the quality. And then information fusion is conducted on thedynamic characteristic quantity data, such that nonlinear mapping to the tensile-shear strengthof welding spot.VB is applied to compile human-computer interface. Welding data can be derived byusing the interface. And the pretreatment of the welding data, showing curve about the data,changing parameters can all be done through this human-computer interface. Matlab, whichhas the stronger numerical treatment function, is adopted to compile the training function andsimulation function of neural network, and build dynamic link base for VB to call,and finallythe software which can asses online the quality of the welding spot is built. The software canfinally run by itself apart from the Matlab and VB environment. By doing live test, thesoftware can obtain the welding quality when each welding spot is finished, And the toleranceis in the allowable range compared to the value measured actually. Moreover,curve ofchanging of the electrode pressure,electrode displacement and welding current are showed,and this can be a excellent function for workers to refer to in practical application.