This paper deals with the new recording method of holographic interferometry being developed to make capable of observing appreciable wide ranges of strains involving the plastic region. As one of examples using this method, the measurements of the fringe patterns of the deformed cylindrical surface under the axial load were investigated. For purpose of analizing this fringe patterns, the technique of reading the fringe orders and analizing them on the cylindrical surface was proposed. The experimental results indicate that the ratios of heights to diameter have predominant effects on the frictional constrain at the compressed end, and consequently on the shape of the cylindrical surface.

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The paper describes the two different techniques to shorten the computer run time spent by the structure analysis based on Diakoptics. The first technique consists of the neglect of the higher modes of the substructures to be assembled. This approximation technique is efficient when the dynamic characteristics of the total structure are needed for only the lower modes. The second technique consists of the neglect of the unnecessary point displacements. This second technique is efficient when only the external mode shapes or only the compliance transfer function between the specific points are needed for the total structure. The technique gives the accurate results for the points computed.The results of the test analyses show that the computer run time for the calculation based on Diakoptics can be reduced down to about one fifth of that of the conventional finite element method when the proposed techniques are applied to the original method of Diakoptics.

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In this paper, we present a general view on the basic dynamic load rating of a linear motion ball bearing, considering both the fluctuation of load distribution in the bearing during the time of the shaft movement and various positions of eccentric radial load. As an example, we offer calculations, under various working conditions, of the basic dynamic load rating of the bearing of six ball rows and examine the results. The followings are the summary of the results : (1) When the load is applied counter gravitationwise on the outer sleeve of the bearing, the ratios of the basic dynamic load rating of two cases -one is the case when the load is positioned on the mid-line of two ball rows and the other is the case of the load positioned on one ball row- are 1. 1 when the eccentricity factor of working load is zero, and 1. 16 when it is 1. 5. And, the differences affect obviously the traveling life of bearing. However, when the applied loads work gravitationwise, the difference is negligible. (2) It can be said that the basic dynamic load rating decreases remarkably in accordance with the increase of load eccentricity factor, and that it tends to increase in accordance with the increase of shaft stroke.

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Stepping motors (pulse motors) are generally used in many various machines because the control system of stepping motor is very simple; the motion. of stepping motor need not be fed back to the driver circuit of the stepping motor. But the stepping motor involves the several vibration problems that are the residual vibration at the step motion, the uneven revolution at the steady rotation, and the discordance because of the resonance of stepping motor. This paper shows the way of how to resolve these vibration problems by attaching a dynamic vibration absorber to the stepping motor. In this study the optimal parameters of the dynamic vibration absorber are given as β=1/ (1+α) and Ca =√α/ (1+α). These optimal parameters are different from the optimal parameters that aim to minimize the steady state vibration with an affection of external force. Here, α is the ratio of inertia of the dynamic vibration absorber and the rotor of the stepping motor including the inertia of load. β is the ratio of undamped natural frequencies of the dynamic vibration absorber and the stepping motor that is excited. ζ_d is the damping ratio of the dynamic vibration absorber.

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The surface generation process is investigated in the rotation/reciprocation lapping by treating surfaces of upper and lower workpieces as those of the fourth order of revolution. The treatment is shown to be valid to express some surface undulations which are inherently caused in the process. Simulated and experimental results indicate that the changes in surface shapes of upper and lower workpieces, expressed by trajectories in a four dimensional space, are constructed by combined flows determined by two different vector fields which are assigned to each of their territories. Further, fundamental properties found in treating surfaces as those of second order of revolution are revealed not to be disturbed by an introduction of the fourth order components into the initial surfaces.

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It is universally admitted that the grinding sound is of considerable utility as the informational medium of grinding phenomenon. The sound radiation of grinding wheel, which is one of the sound sources in the grinding process, has not yet been clarified although it caused a lively concern. In the present paper, the discussion on the characteristics of sound radiation from the grinding wheel are based on its acoustic constant. The experimental results obtained are as follows. (1) The grinding sound pressure level tends to increase with the value L_c·t_max and level off when the mean cutting force is equal to the strength of bond bridge. (2) The highly peaked constant bandwidth spectra of the grinding sound appear at the frequencies which agree very well with the natural frequencies of grinding wheel. (3) The highly peaked spectrum levels also increase with the value L_c·t_max, especially the effect of increased undeformed chip thickness t_max is larger than the effect of increased undeformed chip length L_c.

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In order to get the directions for the design of adhesive joints, the stress distribution in the adhesive layer of a modeled adhesive joint under shear, tear or tensile load has been analysed by using the finite element method. It has been shown that there is the stress concentration at the corner composed of the free surface and the adhesive-adherent interface of adhesive layer for the respective loads, and that the stress distribution at the mid-plane of the adhesive layer is uniform. The stress concentration tends to increase, except for the tensile load, when the Young's modulus of the adhesive increases, and is largest under the tear load. Therefore it is recommendable to use an adhesive of low stiffness and soft for a joint to be used under tear load. Furthermore, the validity of Volkersen's and Goland & Reissner's equations, which are popularly used to determine the maximum shear stress of lapped joints, has been discussed comparing the results analysed for shear load with these of both equations.

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This paper presents the method of decreasing drunkenness of a leadscrew by means of a mechanical lapping device. Drunkenness which is cyclic error in one lead is difficult to be eliminated only by grinding and therefore it is finally eliminated by hand lapping which depends on perception of a skilled worker. The purposes of this paper are : (1) to lap a annular thread which has undulation corresponding to the drunkenness of a leadscrew and (2) to lap the screw thread based on the data of lapping annular thread, to observe the phenomenon of decreasing drunkenness and to discuss about it. As a result, the undulation could be decreased gradually. As for practical screw thread, two methods of lapping are applied. By one method, the drunkenness could be decreased up to about 1/4 of the original one, and by another method the drunkenness could be almost eliminated.

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This paper deals with basic and systematic estimation for the residual stress formation in ground surface layer due to grinding force and grinding temperature by using the finite element method. Furthermore, we also investigated in relation to the mechanical and thermal residual stress distributions and influential dominating factors such as work speed, heat transfer coefficient of grinding fluid. The main results obtained were as follows : (1) The residual stress in the ground surface layer is very close to the value calculated by the grinding temperature. And the residual stress formed by the grinding force is very small value till the value can be neglected. (2) The residual stress in the ground surface layer calculated by the FEM corresponds to the measured distribution. (3) The work speed and heat transfer coefficient of grinding fluid in relation to the grinding temperature are considered as most influential dominating factor of magnitude of the residual stress.

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The dissolution behavior of Ni-Cr alloys from 4 % to 20% Cr has been studied in 3 M NaNO₃ solution at 30°C. The polarization measurements were carried out in static and flowing electrolytes, and the current efficiency measurements were carried out in flowing electrolyte over a range of current densities from 1 to 100 A/cm². X-ray photoelectron spectroscopy and X-ray microanalysis were then used to examine the sample surface after the dissolution tests. The results show that Ni-Cr alloys dissolve in transpassive state at the potentials above 0.8 V (vs. SCE). For the alloys containing ≤18% Cr, the secondary passivation takes place with increasing anode potential and current density. The secondary passivation film is very thin and is com posed mainly of Ni (II) and Cr (III). The dissolution current efficiency of ithe alloys containing ≤14 % Cr is only 5-30%, and a major part of the current is consumed in oxygen generation. For the 16% Cr alloy and the 18% Cr alloy, severe grain boundary attacks take place at moderately high current density. The 20% Cr alloy dissolves at 100% current efficiency at all current densities with a thick film composed mainly of Ni (II) and Cr (VI).

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In this paper, the formation process of saw-toothed type abrasion pattern generated on the ground surface by rubber grinding and the effects of grinding conditions and rubber materials upon the surface roughness are discussed. Grinding tests were performed in cylindrical plunge grinding of NBR (acrylonitrile butadiene rubber) and CR (chloroprene rubber), and the ground surfaces were observed with a microscope and a surface roughness meter. The main results obtained are as follows : (1) The distance and the height of saw-tooth on ground surface are proportional to speed ratio and plunge speed, but are inversely proportional to apparent distribution density of abrasive grain. (2) The distance and the height of saw-tooth are independent of rubber materials but are determined by these static modulus of elasticity E_s, and are in inverse proportion to E_s. (3) The mean values of chip thickness calculated from the ratio of sawtoothed pattern and the depth of cut per one revolution of workpiece in steady grinding state coincide fairly with the measured values.

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A new traverse grinding technique with the grain size variation wheel, in which grain size is varied layer by layer along wheel width, is introduced for improving both efficiency and surface finish. The grain size variation wheel has the leading part of coarser grain and following finer grain parts on the acting wheel surface, and the leading part of coarser grain removes mainly metal and following parts of finer grain sizes improve surface finish. The traverse grinding process is experimentally analyzed and compared with the conventional one to prove that the new technique is available for higher efficiency and better surface finish as compared with the traditional one, because the whole width of the grain size variation wheel is effective and respective parts on the acting wheel surface play respective roles. The grinding ability of the grain size variation wheel is also maintained well for long grinding time and therefore the surface finish and the grinding force are kept constant with grinding time in the traverse grinding, because the wear rate of the grain size variation wheel is lower than that of the traditional wheel.

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A sensor by means of fiber optics is proposed to estimate the degree of surface finish of a curved metal surface as well as a fiat metal surface. The proposed optical fiber bunble is arranged in a concentric distribution. The transmitting fiber bundle is located at the center and is surrounded by the receiving fiber bundle. From the theoretical analysis of the concentric distribution optical fiber bundle, the following results are obtained : (1) The specular reflection measured by the optical fiber bundle depends on three values with respect to its dimensions, namely, the radius R_i of transmitting fiber bundle, the aperture angle α and the area ratio m of the receiving fiber bundle to the transmitting fiber bundle. (2) The region in which the specular reflection is insensitive to the changes in the measuring distance extends, as the radius R_i increases or the aperture angle α decreases. (3) An optical fiber bundle having values of α=7 degrees, R_i=0.6 mm and m=1 is suitable for gloss measurement of a curved metal surface of which the radius of curvature is over ±15 mm.

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For the purpose of elucidating the controlled force plunge grinding mechanism S 45 C material (0.45% Carbon Steel) is ground by using WA vitrified wheel with a prescribed plunge pressure p (4.1-13.1 kgf/cm²), and the stock removal rate (depth of cut per one wheel revolution), the tangential grinding force, the radial wheel wear, the finished surface roughness, and the wheel topography (for example W₀; the mean volume occupied by one grain cutting edge at the wheel depth 1 μm, and tan α; the mean value of the tangent of half the grain cutting edge tip angle α) are measured. The results are discussed on the basis of the theoretical analysis reported in the previous paper and the followings are obtained : (1) The stock removal rate. which is proportional to p^1.17D^1.02W₀^0.15 (tan α) 0.97 approximately (D is the wheel diameter), decreases gradually with the lapse of grinding time and in the final stage rubbing of wheel on the workpiece without cutting takes place. (2) The wheel wear process, which takes dulling type under the plunge pressure applied in the experiments, trends toward a satisfactory wear process in which self-sharpening occurs frequently when larger plunge pressure is applied.

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The divided tool technique, which has been used for measuring the stress distribution on the toolchip interface, is extended to evaluate the penetration depth of cutting fluid into the interface. When the fluid is applied in the usual manner, some of it transudes to the interface through the dividing gap of the tool and will reduce the cutting force, if the gap is located in the unpenetrated region of the interface for regular non-divided tool. In a similar way, blowing of compressed air from the gap will increase the force, if the gap is in the penetrated region. It is thus possible to evaluate the penetration depth by measuring the cutting force with changing the location of the gap. Several examples of the penetration depth and stress distribution on the interface are presented. While a large unpenetrated region remains at higher cutting speeds, cutting fluid does penetrate all over the interface including cutting edge at very slow cutting speeds. It is also found that non-active fluid such as benzen and paraffin are quite effective for machining copper, while they are not effective for machining carbon steel and aluminium. Copper appears to act as a catalizer for the mechanochemical decomposition of hydro-carbon, and the resulted hydrogen must play an important role.

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[in Japanese]

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