波纹位置对顶部凹陷膜片翻转行为的影响研究

RESEARCH ON EFFECT OF CORRUGATION LOCATION ON EXPULSION BEHAVIORS OF SPHERICAL-DISHED DIAPHRAGMS

原顶部凹陷膜片的波纹结构位于膜片球形旋转段下端时,其翻转效率较差,针对这一问题,该文将波纹结构设置到临近顶端凹陷区域。利用有限元法,数值计算原膜片与改进型膜片的屈曲与后屈曲状态。对这两种膜片的研究结果进行对比分析,得出:改进型膜片的屈曲模态更利于膜片翻转,且翻转效率更高;改进型膜片避免了易导致原膜片失效破坏的严重偏心与褶皱问题;改进型膜片的最大应力状态较原膜片有显著降低,可防止膜片在翻转过程中达到材料的极限应力而发生破裂。

When a corrugation structure is located in the bottom of original spherical-dished diaphragms, expulsion efficiency is low. In order to heighten the expulsion efficiency of diaphragms, a corrugation structure is located near a dished section. The buckling and post-buckling equilibrium configurations of original and modified diaphragms are numerically analyzed by the finite element method （FEM）. By the comparison of research results about the two diaphragms, the conclusions are as follows： modified diaphragms are better for expulsion than the original ones, and the former has higher expulsion efficiency; severe eccentricity and folding problems, which are likely to cause fracture failure of the original diaphragms, do not happen in the modified ones; the maximum Von Mises stresses of modified diaphragms are much smaller than that of original ones, which indicates modified diaphragms are less probable to reach the limit stress of the material during an expulsion process.