http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Numerical Simulation of the Twist Deformation for the Stiffened Panel with Laser Forming
Shouchong Fu,Lijun Yang,Hongzhi Zhang,Yang Wang,Guanxin Chi,Ye Ding 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.10
In the laser forming process of the panel with crossed reinforcing bars (PWCRB), a kind of stiffened panel, twisting of the panel occurred when it was formed under the integral continuous scanning strategy (ICSS). The twisting was restrained obviously when the middle stiffener was heated. In order to reveal the twisting mechanism, a FE model was established and corresponding simulations were conducted. Furthermore, an equivalent model of the sectional structure was established, and a model of the buckling critical load of the stiffener was established based on principle of minimum potential energy. It revealed that the buckling critical load of the middle stiffener was smaller than that of the marginal stiffener. The simulation results showed that the stiffeners suffered from pressure and bending moment during the forming process, which tended to induce the buckling of the stiffeners. Besides, the residual stress of the middle stiffener was larger than that of the marginal stiffener. The bending angle of the middle stiffener increased when it was heated. Besides, the lateral-torsional deformation of the middle stiffener decreased and the twisting of the panel was restrained. It demonstrated that the twisting phenomenon of the PWCRB was caused by the middle stiffener, which suffered from lateral-torsional buckling when the panel was formed with the ICSS.
Analyses of Effects of Process Parameters on Laser Bending of Stiffened Panels
Shouchong Fu,Lijun Yang,Hongzhi Zhang,Yang Wang,Guanxin Chi 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.4
In this paper, laser forming technology was extended to form the stiffened panels. Compared with the plate with constant thickness, the stiffened panel was a type of panel with complicated structure and was hard to form. In order to gain a profound insight into the deformation characteristics of the stiffened panel under laser forming, a finite element model was established. The effects of process parameters on the deformation characteristics were investigated in terms of temperature distribution, stress and strain distribution. The influences of the process parameters on the unexpected deformation were analyzed by analyzing the influences of the process parameters on the maximum temperature theoretically. The results showed that laser spot diameter had the most important effect on the maximum temperature followed by the laser power and scanning speed. So when the scanning speed changed, the variation of the difference of the plastic strain between the top and bottom surface was the smallest.When the laser spot diameter decreased, the increment of the maximum temperature, the plastic strain as well as the deformation of the middle position of the scanning path was the largest. The increase of the deformation of the middle position of the scanning path could decrease the degree of the nonuniformity of the deformation of the free end, namely increasing the quality of the formed panel.