夹层板精密成形的数值模拟

为了实现基于“点阵钉模、真空负压、蜂窝夹层”的双曲度面板精密成形过程的有限元数值模拟,分析了成形 2个阶段的变形过程,建立了简化的力学模形,以一种广义协调薄板弯曲四边形位移单元为基础构造了具有公共横向位移自由度的几何非线性四边形四节点分别考虑和不考虑横向剪切的多层板单元,通过牛顿 -拉斐逊法结合载荷、位移约束量的增量法求解几何非线性方程,较好地再现了真实成形过程

NUMERICAL SIMULATION FOR THE PRECISE FORMING OF SANDWICH PANELS

In order to simulate the precise forming of a double curvature panel based on "nails die, vacuum and honeycomb sandwich" by the finite element method, a simplified mechanical model for the two forming phases is established. The forming process for each phase is analyzed by means of the geometrically nonlinear quadrilateral four node multi layer plate element based on a kind of generalized conforming thin plate bending quadrilateral displacement element with public transverse displacement freedom degrees. The geometrically nonlinear equations are solved by the Newton Raphson method combined with the incremental method of load and displacement constraint. The numerical technique in this paper can be applied to the processing simulation and the springback prediction for precise forming of sandwich panels.