Some parts with capillary to plate joint have important application in aerocrafi. Vacuum electron beam brazing (VEBB) technology is used to realize this jointing with capillaries. Firstly 3D finite element analysis ...Some parts with capillary to plate joint have important application in aerocrafi. Vacuum electron beam brazing (VEBB) technology is used to realize this jointing with capillaries. Firstly 3D finite element analysis model is built in this paper according to this special structure. And then ANSYS finite element analysis software is used to analyze brazing temperature field at different brazing parameters. The calculation results show that the temperature field of simulation has good agreement with that measured by experiment, which proves dependence of the model built in this paper. And also reference parameters could be provided for real brazing process through calculation in this model. Brazed joint of capiUary to plate with good performance is achieved using VEBB technology. The achievement of the study will be applied in aerocrafi in the future.展开更多
Based on thermal-elasto-plastic finite element theory, a two-dimensional finite element model for calculating electron beam brazing temperature and residual stress fields of stainless steel radiator are presented. The...Based on thermal-elasto-plastic finite element theory, a two-dimensional finite element model for calculating electron beam brazing temperature and residual stress fields of stainless steel radiator are presented. The distributions of temperature and residual stress are studied. The resuhs showed that temperature distribution on brazing surface is rather uniform, ranging from 1 026 ℃ to 1 090 ℃. The residual stresses are varied from initial compressive to tensile , and the variation of residual stress is very little in total zone of brazing surface.展开更多
Based on full scale model of 1-beam and end-plate welding assembly with medium plate, welding temperature field and residual stress were simulated, infrared thermometers were employed to measure the real-time temperat...Based on full scale model of 1-beam and end-plate welding assembly with medium plate, welding temperature field and residual stress were simulated, infrared thermometers were employed to measure the real-time temperature Jbr verification purposes. Results show that the measured thermal cycle curves match well with the simulation result. Simulation results of welding residual stress indicate that the values of longitudinal and transverse stress on the upper surface of the plate are higher than the normal stress; higher tensile stresses exist at the end of the web weld toes and in the central area of the flange weld toes. The dangerous zones are located at the central areas of weld toes of the flange welds and near weld toes of the web welds.展开更多
The temperature and stress profiles of porous cubic Ti-6Al-4V titanium alloy grids by additive manufacturing via electron beam melting(EBM)based on finite element(FE)method were investigated.Three-dimensional FE model...The temperature and stress profiles of porous cubic Ti-6Al-4V titanium alloy grids by additive manufacturing via electron beam melting(EBM)based on finite element(FE)method were investigated.Three-dimensional FE models were developed to simulate the single-layer and five-layer girds under annular and lateral scanning.The results showed that the molten pool temperature in five-layer girds was higher than that in single-layer grids owing to the larger mass and higher heat capacity.More energies accumulated by the longer scanning time for annular path than lateral path led to the higher temperature and steeper temperature gradient.The thermal stress drastically fluctuated during EBM process and the residual stress decreased with the increase of powder layer where the largest stress appeared at the first layer along the build direction.The stress under lateral scanning was slightly larger but relatively more homogeneous distribution than those under annular scanning.The stress distribution showed anisotropy and the maximum Von Mises stress occurred around the central node.The stress profiles were explained by the temperature fields and grids structure.展开更多
文摘Some parts with capillary to plate joint have important application in aerocrafi. Vacuum electron beam brazing (VEBB) technology is used to realize this jointing with capillaries. Firstly 3D finite element analysis model is built in this paper according to this special structure. And then ANSYS finite element analysis software is used to analyze brazing temperature field at different brazing parameters. The calculation results show that the temperature field of simulation has good agreement with that measured by experiment, which proves dependence of the model built in this paper. And also reference parameters could be provided for real brazing process through calculation in this model. Brazed joint of capiUary to plate with good performance is achieved using VEBB technology. The achievement of the study will be applied in aerocrafi in the future.
文摘Based on thermal-elasto-plastic finite element theory, a two-dimensional finite element model for calculating electron beam brazing temperature and residual stress fields of stainless steel radiator are presented. The distributions of temperature and residual stress are studied. The resuhs showed that temperature distribution on brazing surface is rather uniform, ranging from 1 026 ℃ to 1 090 ℃. The residual stresses are varied from initial compressive to tensile , and the variation of residual stress is very little in total zone of brazing surface.
基金This research was supported by the National Natural Science Foundation of China (51171093).
文摘Based on full scale model of 1-beam and end-plate welding assembly with medium plate, welding temperature field and residual stress were simulated, infrared thermometers were employed to measure the real-time temperature Jbr verification purposes. Results show that the measured thermal cycle curves match well with the simulation result. Simulation results of welding residual stress indicate that the values of longitudinal and transverse stress on the upper surface of the plate are higher than the normal stress; higher tensile stresses exist at the end of the web weld toes and in the central area of the flange weld toes. The dangerous zones are located at the central areas of weld toes of the flange welds and near weld toes of the web welds.
基金The work was financially supported by the Natural Science Foundation of Shandong Province,China(No.ZR2019MEM012)the Major Scientific and Technological Innovation Program of Shandong Province,China(No.2019JZZY010325)+1 种基金the Key Research Program of Frontier Sciences,CAS(No.QYZDJ-SSW-JSC031-02)the National Natural Science Foundation of China(No.51871220).
文摘The temperature and stress profiles of porous cubic Ti-6Al-4V titanium alloy grids by additive manufacturing via electron beam melting(EBM)based on finite element(FE)method were investigated.Three-dimensional FE models were developed to simulate the single-layer and five-layer girds under annular and lateral scanning.The results showed that the molten pool temperature in five-layer girds was higher than that in single-layer grids owing to the larger mass and higher heat capacity.More energies accumulated by the longer scanning time for annular path than lateral path led to the higher temperature and steeper temperature gradient.The thermal stress drastically fluctuated during EBM process and the residual stress decreased with the increase of powder layer where the largest stress appeared at the first layer along the build direction.The stress under lateral scanning was slightly larger but relatively more homogeneous distribution than those under annular scanning.The stress distribution showed anisotropy and the maximum Von Mises stress occurred around the central node.The stress profiles were explained by the temperature fields and grids structure.