Outer Edge Of Plate Research Articles

Study on Rotary Bending Forming Process of Torsional Damper Shell Pulley

To study the integral forming process of torsion damper shell pulley with characteristic structure is of great significance for producing and developing of the rotational part such as shell pulley. A processing way was proposed by combining plate bending forming and roller structure design, to integral forming torsion damper shell pulley. A model for two-step bending forming was establishedvia finite element method. Under the radial feeding of roller, the outer edge of plate was subjected to compress thickening and secondary thickened after bending, and effective stress and metal flow in the deformation zone were analyzed by using marking point. Combining with the structural characteristics of shell pulley, a design criterion "rotating thickening, gathering thickening" of roller was proposed. The metal flow in deformation zone was effectively controlled through the characteristic structure of roller, thereby the specific region to forming multi-wedge toothwas obtained. The quantitative analysis of the instantaneous part section in the forming process, combining with the design criteria of roller structure and material flow rate, radius and arc angle of roller were determined. With the objective forming parameters, the comparison between the simulation results and the experimental are basically coincided, the ribs were fully formed and the specific regions was thickened to minimum value, which verified the feasibility of sheet-bulk metal rotary bending forming theory and the design criterion of roller structure.

Free vibration analysis of piezoelectric coupled annular plates with variable thickness

This paper presents the free vibration analysis of piezoelectric coupled annular plates with variable thickness on the basis of the Mindlin plate theory. No work has yet been done on piezoelectric laminated plates while the thickness is variable. Two piezoelectric layers are embedded on the upper and lower surfaces of the host plate. The host plate thickness is linearly increased in the radial direction while the piezoelectric layers thicknesses remain constant along the radial direction. Different combinations of three types of boundary conditions i.e. clamped, simply supported, and free end conditions are considered at the inner and outer edges of plate. The Maxwell static electricity equation in piezoelectric layers is satisfied using a quadratic distribution of electric potential along the thickness. The natural frequencies are obtained utilizing a Rayleigh–Ritz energy approach and are validated by comparing with those obtained by finite element analysis. A good compliance is observed between numerical solution and finite element analysis. Convergence study is performed in order to verify the numerical stability of the present method. The effects of different geometrical parameters such as the thickness of piezoelectric layers and the angle of host plate on the natural frequencies of the assembly are investigated.

Stability of variably thick orthotropic annular plates

The static and dynamic stability of variably thick orthotropic annular plates subjected to in-plane periodic forces with respect to time is studied. It is assumed that the periodic radial forces with the same period act along both the inner and outer edges of plate. The finite element method is used with a sector element based on the Mindlin plate theory. The wave propagation technique of cyclic symmetry is used in the formulation. The choice of the element enables the analyst to solve the axi-symmetric and asymmetric dynamic stability problem at the same time. Variations in the plate thickness in which it increases or decreases in the radial direction according to the equations h = h max ( r r o ) +λ or h = h max ( r r i ) −λ , respectively are considered. The instability regions for different boundary conditions are determined by Bolotin's method. It is found that the critical buckling load, buckling mode and instability regions are changed by variations in the polar orthotropic material properties.