If the crossterms of the spatial frequencies for the unit cell of periodical object are much smaller than the main frequency terms, the restriction of the Angle is not necessary.
当周期物体的单胞空间频率交叉项比主频率项小到可忽略的程度时,角度限制失效。
2
The present model, as a simplified, practical but precise method, can simulate foundation stiffness matrix including the principal terms and the crossterms. It is worthy of widely application.
Unlike the traditional kernel function methods to suppress crossterms, our method not only reduces the interfering cross-terms but also preserves the superb time-frequency concentration of the WVD.