Steady Shape Research Articles

Studies of Electrochemical Machining : 2nd Report, Investigation of the Shapes by Electric Tank Simulation

The objective of this paper is to establish general relationships that exist between the configuration of the electrode and the sunken cavity on the basis of the potential distribution measured in the gap between their enlarged models placed in the electric tank. From the electric tank simulation experiments, the electric field intensity (or the current density) at any point on the surface of the steady state shape is found to be proportional to sine of the angle contained between feed direction of the electrode and the tangent of the steady state shape at that point. Anticipation of the shape which will be produced by ECM with the given electrode under the given processing conditions is carried out by the electric tank simulation method. According to the results, the shape anticipated from the electric tank simulation coincides with the shape produced by ECM and the shape calculated according to the theoretical analysis in the 1st report.

Studies of Electrochemical Machining : 1st Report, Theoretical Analysis for the Work Shape Processed by ECM

This paper deals with the formation of work shape in the electrochemical machining (ECM) theoreticall and experimentally. On the basis of calculation about equilibrium working gap between the electrode and the workpiece under the effect of constant applied voltage and constant electrode feeding rate, the generating process of work shape in three dimensional die sinking is followed. The results show the mechanism of the work shape attaining steady state through the transient state with processing time. Further, characteristic relationships between the steady state shape of the workpiece and the configuration of the electrode are made clear theoretically. These results obtained from theoretical analysis are demonstrated by experimental investigations on die sinking with trapezoidal electrodes under various ECM conditions.

Aeroelastic Problems of Low Aspect Ratio Wings

A method is presented for calculating the aerodynamic forces acting on an elastic supersonic wing having arbitrarily swept straight leading edges and a supersonic trailing edge. The loads are presented in matrix form in terms of the geometrical incidence effective at given wing structural stations. It is thus possible, by combination with the corresponding structural matrix, to determine the steady state aeroelastic loading and final shape of the wing. It is shown how the distribution of loading associated with the placing of incidence on a small quadrilateral area within the wing plan form may be calculated. This loading is broken down into point loads acting at the required structural stations by graphical integration. The loading due to each small area is built up by superposing solutions obtained from linearized supersonic control surface theory. The sweep of the hinge line, and its relation to the wing Mach lines and leading edges are the main parameters of the problem. Twelve formulae are presented, giving the loading in each of the various regions likely to occur for practical wings. By a proper combination of the loads acting on symmetrically opposed stations on each side of the wing, the symmetric or anti‐symmetric aerodynamic matrix can be formed, corresponding to pitching and plunging, or rolling motions of the wing respectively.