Deformation Prediction And Welding Sequence Optimization Of Titanium Cabin Using Laser Spot Welding

Laser spot welding can effectively reduce the deformation and inconsistent qualityof titanium aerospace structure compared with resistance spot welding, quickly adaptingto the upgrading of products. However, carrying capacity and deformation of structurealso exist when using laser spot welding. For the fabrication of certain electronic cabin,experiment and mechanical properties of laser spot welding are researched in this paper,as well as the deformation of the whole structure using numerical simulation method,providing a basis for the application of laser spot welding on the electronic cabin.Firstly, the welding process and mechanical testing of traditional laser spot weldingwas carried out. As for its lower shear performance, several new shaped welds wereredesigned to improve the mechanical properties of laser spot welding. The resultsindicated that the carrying capacity was related to the fusion surface of the weld.Restricted to the structure’s characteristics, the designed Ring Weld could not meet therequirements of the mechanical properties. At the same time, C Weld and Double StitchWeld exceeded the standard compared to the resistance spot weld.Secondly, finite element model was carried out to simulate the temperature,residual stress distribution and deformation of the titanium plate specimens. Thetemperature-dependent thermal physical properties were taken into account and thesimulation results eventually had a good agreement with the experimental data. Theresults also showed that the lower cooling time after welding not only simplified theanalysis process, but also reduced the welding deformation.The quantity of welding spot was reduced to simplify the simulation process anddeformation of structure was compared between C Weld and Double Stitch Weld. Theresults showed that C Weld exhibited lower deformation and thus confirmed as thesuitable weld shape when welding titanium electronic cabin. On this basis, the influenceof welding sequence was discussed, as well as the deformation control measures. As asequence, the corresponding welding fixture was designed for the welding of titaniumelectronic cabin.At last, the weld deformation of the entire structure which contained the wholequantity of weld spots was researched. Four typical welding sequences were discussed, and the simulation results indicated that symmetrical welding from the middle to bothsides of the cabin had the smallest deformation. The results could guide the practicalmanufacture, accordingly reducing costs and improving efficiency.