In this paper, a new method for the separation of principal stresses is described, which consists in combining the following data : isoclinic parameter and isochromatic fringe order measured by the conventional method, and also the fringe order distributinon obtained by the scattered-light method. As the photoelastic material, polycarbonate resin with a good transparency was used. Besides, using the circularly polarized light in the scattered-light method, fractional fringe orders were determined from the rotated angle of the polarizer, as is practiced in Tardy's method. This method was appleid to two well-known problems already solved theoretically. The experimental results were compared with the corresponding theoretical solutions and a good agreement between these results showed the practicability of this method. Throughout the experiment, it was shown taht the experimental procedure was simple and the calculation of prindipal stresses was easier than the conventional methods.

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In this paper are described the effects of the vane-angle β₀ and the nozzle inclination-angle α₀ and the annular slit ratio 2b₀/D on the velocity and static pressure distributions in swirling and unswirled air jets issuing from annular nozzle. The following characteristics were clarified from the experiments : the characteristics of swirling jets (2b₀/D<0.4) are mainly affected by β₀ and slightly by α₀ and 2b₀/D. In the case of β₀<60°, a region of subatmospheric pressure exists near the nozzle exit. Therefore, main stream lines of the jet are deflected toward the nozzle axis, and the main stream surface formed by these lines becomes asymptotically a cylindrical surface in far downstream region. The unswirled annular jets become circular ones at a short distance from the nozzle exit. The characteristics of the jet in the downstream region are similar to those of circular free jet.

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It this paper is described a theoretical analysis of the swirling jets issuing from an annular nozzle. An approximate calculation method for trajectory of the main stream line has been derived. And velocity distributions are obtained by solving momentum integral equation for the orthogonal curvilinear coordinates using the trajectory of the main stream line as coordinate. The values of coefficients in the equations are determined by experiments. And the theoretical predictions from the values of these constants agree with the experimental results.

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In part 1 of this series it is attempted to describe how the slip velocity in horizontal lines depends on the tube diameter and the transport air velocity, considering momentum losses by the collision of particles with the wall. The direct determination of particle velocities and velocity losses by collision is made, using a combination of a rotating shutter and photographic measurements of particle trajectories. From these results the coefficient suggested by G. Weidner is obtained and it is shown that the experimental results of other investigators can be satisfactorily described with it. It is also explained that the slip velocity becomes constant in the region of lower transport air velocities.

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In order to obtain basic data for designing float-area-type flow meters for various kinds of fluid to be used, a fluid-dynamic analysis on the laminar boundary layer in the annular clearance between the float and the tapered tube is developed. In this analysis a new velocity profile in the laminar boundary layer is used and more precise theoretical results than those reported before about the performance characteristics, i.e. the drag coefficient of a float and the relation between the position of the float and the flow rate, of a float-area-type flow meter are obtained. Results of an experiment carried out with a spindle oil are compared with those of theoretical analysis and good agreement is found to exist between them.

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In this report, a cutting and grinding method of constant depth tooth spiral bevel gears is described, i.e. the gear is formated by the Gleason's No. 0 cutter or grinding wheel having an equal pressure angle on inner and outer blades and the pinion is generated by the No. 0 cutter or grinding wheel whose shaft is not tilted to the rotor axis. In generating the pinion, the pinion blank and the rotor are rotated at the rate of the number of teeth of the pinion to that of the crown gear and at the same time the pinion blank is driven away from the rotor and moreover approached to it. By this method, although it is an approximate one, a good available tooth bearing with a crowning and a profile modification can be obtained on one trial of grinding by the No. 0 wheel only, consequently a mass and small quantity grinding production system of bevel pairs could be achieved.

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In double-helical gear pumps, it is clarified theoretically that delivery characteristics differ in accordance with the direction of gear rotation (called "forward rotation" when central part of the tooth curve first enters the gearing region, and "backward rotation" when ends of the tooth first enter the gearing region), and experiments are conducted using spur gear, single-helical gear and double-helical gear pumps. Results obtained are as follows : (1) Owing to fluid flow across the tooth curves being unfavourable, the theoretical characteristics at backward rotation are worse than at forward rotatio. (2) When there were pressure release ports on both sides of delivery and suction, or on delivery side only, the pumps operating under forward rotation always showed better total efficiencies than pumps operating under backward rotation and having the same type of release ports. (3) When the release port was on suction side only or when there was no release port, no distinct effect of direction of rotation on the total and volumetric efficiencies was observed. (4) Double-helical gear pumps operating under forward rotation showed total efficiencies higher than those of spur gear or single-helical gear pumps. (5) Double-helical gear pumps under backward rotation would have an efficiency equal to or worse than the efficiencies of spur gear or single-helical gear pumps.

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This paper deals with the theory and the experiment on the large plastic deformation of simply supported and clamped beams without axial constraint, each of which is struck with a punch. The equation of motion of beam is solved simultaneously with the equation of the stress wave propagation in the punch so that the condition of contact between the beam and the punch may be satisfied, and the result is compared with the experimental result and moreover with the usual theoretical result in which the punch is assumed to be rigid. Following conclusions are obtained. (1) Plastic deformations of beams proceed while the pundh and the beam are repeating collision and separation. This phenomenon is interesting because it is similar to the ultrasonic woking. (2) The usual theory over-estimates the dynamic yield bending moment of the beam. (3) Since the plastic hinge occupies the position between the impact point and the supports of the beam at the early stage of bending, the straight sides of the bent beams curve inversely.

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This paper deals with the decision of pass schedule of roller in conventional simple spinning. It is important to control the deformation mode of blank by an excellent pass schedule of roller, lest the sheet metal should be wrinkling or fracturing. At first, the authors attempt to draw in sheet metal by four fundamental types of template, namely-linear shape template (revolved and inside shifted type) and circular shape template (outside and inside shifted type). From the experimental results of these types, an involute curve is proposed for the profile of template. According to the test result of the new involute template, it is evident that the height of spun cups can be controlled freely by the alteration of working conditions, and the limit drawing ratio is best improved. The authors obtain the drawing ratio of 2.5 when t₀/d=1.25.

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In the present paper, the axi-symmetric extrusion of the Tresca's solid is analysed by means of the semi-inverse method under the Haar-von Karman hypothesis. At first, the stress field is constructed by assuming the distributions of the pressure and the frictional stress on die surface. Then, the velocity distribution in the slip line field is calculated with the boundary conditions of the velocities of the rigid regions. Here, an arbitrary stream line is considered as the die surface, and the stress and the velocity fields obtained above become the solution of the problem of certain peculiar frictional condition, which is different from the given one. Several iterations of this procedure make the difference sufficiently small. From the numerical calculations, the lower and the upper bounds of the extrusion forces are obtained, which are much better than the usual solutions, and the mean extrusion pressures are found to be 10%∼30% larger than those of the plane strain extrusions. Then the strain distributions are compared with the experimental results analysed by the moire and the gridwork methods.

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