The effects of C, Si, Mn, P and Cu in normalized low carbon steels on fatigue strength are expressed as equations, and the results are extended to higher carbon steels. Sixteen kinds of steels containing above alloying elements are melted according to a statistical design. Tensile and fatigue tests results are analyzed by variance analysis and multiple regression analysis methods. The conclusions are as follows. (1)The correlation among fatigue limits and alloying elements can be expressed with multiple regression equation. (2)Fatigue limit can be expressed as a function of yield strength and quantities of alloying elements. (3)The effects of alloying elements on fatigue limit are similar to those on yield strength.

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The effects of C, Si, Mn, P and Cu in quenched and tempered low carbon steels on fatigue strength were investigated, and the results were extended to higher carbon steels. Sixteen Kinds of steels containing above alloying elements were prepared according to a statistical design. The results of tensile and fatigue tests were processed by variance analysis and multiple regression analysis methods. The conclusions are as follow. (1) The relation between fatigue limit and alloying elements can be formulated by multiple regression analysis method. (2) The relation between fatigue limit Owo and yield strength Os can be formulated as follows. Owo=0.426 Os+[{29(P-0.066)+5.0(Cu-0.71)+16.7} (3) In the case of normalizing, the effects of C, Si, Mn, P and Cu on yield strength are more closely related to fatigue strength than to tensile strength. In the case of quenching and 650°C tempering, however, the effects of C and Mn are more closely related to tensile strength, and those of P and Cu are to fatigue strength.

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The effects of nitrogen and boron in quenched and tempered carbon steels on fatigue strengths were investigated. Four kinds of steels containing above elements were prepared. The results of tensile and fatigue tests were analyzed with H term of the following equation. Ow(α, T)=K(α, T)Os(T)+H(e, α, T) α : stress concentration factor T : heat treatment condition e : alloying element The conclusions are as follows. (1) In the case of quenching and 650°C tempering, the effects of N and B on H term are not noticeable, but there may exist the interaction effect of N and B on static strength. (2) In the case of quenching and 550°C tempering, there may exist some effects of N on fatique strength of plain specimens. (3) K value in above equation can be defined as follows. K=0.426 for plain specimens and K=0.116 for notched specimens with α=3 in heat treatment of normalizing, quenching and 450°C∼650°C tempering.

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The effects of Ni, Cr and Mo on fatigue strengths of low alloy steels for machine structure were investigated. Eight kinds of steels containing above alloying elements were prepared according to a statistical design. The results of tensile and fatigue tests were analyzed by variance analysis and multiple regression analysis methods. The conclusions are as follows : (1) The relation between fatigue limit Owo and alloying elements can be formulated as follows, Owo=3.3(Ni-1.27)+11(Cr-0.88)+20(Mo-0.13)-6.7(Ni-1.27)(Cr-0.88)+51.4 (2) The relation between fatigue limit Owo and yield strength Os can be formulated with correction terms of alloying elements as follows, Owo=0.426Os+{1.5(Ni-1.27)-8.8(Mo-0.13)+2.9(Ni-1.27)(Cr-0.88)+16.1} (3) The fatigue notch factor β of steels tested is almost equal to the stress concentration factor α of specimens. However, β of Ni-alloed steels is slightly higher than that of other steels.

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The expression for stress fields in a plastically deformed polycrystalline aggregate is derived by use of two methods; the one is based on the Duhamel analogy which is used by Lin and Ito, and the other is based on Eshelby's transformation problem which is used by Kroner or Budiansky and Wu. The revised formulations yield the same result for both methods and the expression by Kroner et al. is found to be correct in a sense of 'arrangement average'. The self-consistent model proposed by Hill against Kroner et al. is examined.

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We make a stress analysis on the above problem by means of a couple of stress functions with subsequent Fourier-Bessel expansion of the given loads on the boundary, and we propose a new method for a numerical calculation of stress components. First, stress functions are obtained for a general loading condition. Next, stress functions and stress components are obtained for a typical example, and then we perform a numerical calculation of stress components. In the course of our calculation, we expand the part of hyperbolic functions of integrand contained within the stress functions expressed in infinite integrals by Maclaulin law. Thus, integrating by terms, we obtain each stress component. Then, we solve the simultaneous linear algebraic equations with four unknowns so as to satisfy the boundary conditions at two given points on the boundary. The result will show that we are able to obtain an approximate solution in finite terms sufficiently accurate for practical use.

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This paper is concerned with the numerical analysis of large creep deformations of thin shells of revolution under an axisymmetric load with applications to metallic bellows. The mathematical theory of creep as it applies to thin shells of revolution undergoing considerably large deformations is developed for two hardening laws. The basic differential equations derived for incremental values with respect to time or load are numerically solved by a finite difference method, and the solutions at any time are obtained by integration of the incremental values. As a numerical example the problem of creep deformation of metallic bellows important in practical use is treated. It is shown that in creep deformation of thin shells such as bellows, the difference between solutions from linear theory and those form non-linear theory becomes large, therefore the non-linear theory should be employed. The results of the prediction method agree well with experimentally determined values for aluminium annular plates at room temperature.

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This paper deals with a problem of flexural wave propagation in an infinite elastic plate with a circular hole subjected to dynamical loads at the hole. In the approach presented herein, the effects of rotatory inertia and thickness-shear in the plate are considered and the Fourier transform method is applied to this problem. As a numerical example, we treat a case when the motion of the load is sinusoidal. When the thickness of the plate is small compared with a wave length, the results obtained coincide with the ones by the classical plate theory. The differences in the results between improved plate theory and the classical one are also discussed.

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It is well known that for small axial-distance between moving and stationary blade rows in axial-flow blower, interference arises on the blades, and the force acting on the blades fluctuates. The main causes of this interference are the relative movement of the circulation induced by the blades and the wakes which flow downstream form the moving blades. Many studies have been made concerning this problem, mainly from a theoretical point of view, but experimental studies are few. In this study, we analysed the interference between moving and stationary blade rows in an axial-flow blower. Four variations of a single stage axial-flow blower with the stationary blade row behind the moving blade row and with the same performance were used. The number of moving blades was 3 or 9, and thin aerofoil or NACA 65-Series profile was used for the moving blade. Measurements were made of the fluctuating forces on the stationary blades for various axial-distances between blade rows. Comparisons of the fluctuating forces calculated following the method of Kemp and Sears were made.

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Aerodynamic characteristics of an airfoil moving in a narrow channel bounded by two parallel walls, i.e. ground and ceiling, are studied theoretically and experimentally. Lift acting on an airfoil at a positive attack angle increases as the airfoil approaches either ground orceiling. This study deals with the combination of ground and ceiling effects to realize a high lift wing. A theory is presented for the calculation of two-dimensional inviscid flow around an arbitrary airfoil placed in a narrow channel, using singularity method in which proper circulation is distributed directly on the airfoil contours. Sample calculation shows the influences of ground and ceiling on the lift and moment coefficients of the airfoil. Two-dimensional experiment is conducted to measure the pressure distribution of airfoil, from which lift and pressure drag coefficients are evaluated. Theoretical and experimental results are compared and the characteristics of this kind of high lift wings are discussed.

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Experiments on dual jet, issued from two parallel slot nozzles set on a common end wall, were reported in the 1st report. In this report, the measurement of flow in hte combined flow region of the dual jet are discussed. From these measurements, effects of distance between these two nozzles on the flow field were studied and the characteristics of combined flow are compared with those of a single jet. A summary of the results is as follows : (1) The velocity profiles of the combined flow are similar and agree well with the theoretical profile of the single jet, but the distributions of the turbulence intensities show a different property from those of the single jet. (2) The width of combined jet spreads linearly in the downstream direction and inceases with the distance between two nozzles. (3) Because of the negative pressure distribution in the combined jet, the total momentum fluxes in the downstream direction are not conserved, and the decay of the maximum velocity is stronger than that of a single jet.

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Experiments were carried out concerning heat and mass transfer between falling water film and upward air flow in a rectangular vertical duct with a large aspect ratio under the various conditions of rate of flow, water temperature and humidity. The behaviour of the falling water films, e.g., the film thickness and the wave inception, was also examined. The results represented in terms of teh Nusselt number and Sherwood number can be explained using the Reynolds Number based on the mean air velocity relative to the water surface regardless of the water flow rate. When the water temperature at the entrance is varied from 20 to 50°C, the Nusselt number increases, while the Sherwood number decreases in spite of an increases in the rate of evapotation. When saturated humid air is supplied, the Nusselt number is larger and the Sherwood number is slightly smaller compared with air having a relative humidity of 65 per cent.

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In the present paper, the most effective utilization of lean premixture has been discussed on the basis of the combustion photographsunder different distributions or states of auxiliary fuel. The following points have been confirmed : The intermediates of auxiliary fuel have especially marvelous effect on the mist zone of main fuel spray. Thus, the distribution or the state of pre-mixture in an open chamber diesel engine has often diverse influences on the combustion process. For example, if main fuel is injected in completely gaseous and reactive pre-mixture, the spray wipes the mixture away, and branching reaction takes place in the mixture concentrated. Therefore, the injection in such a mixture has possibly unfavourable effect on the improvement of the combustion of main fuel. From the above facts, it will perhaps be a highly beneficial utilization of lean pre-mixture to push out the auxiliary fuel, which is partially vapourized, by main fuel spray. This is because a contact area is larger and its duration is also longer.

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Similarly to other combustion systems, reduction of ixides of nitrogen emitted from diesel engines is one of the urgent problems to be solved from the viewpoint of photochemical smog. However, their formations are not fully understood yet and the effects of engine variables on their emissions are still not well known. In this paper, the tendency of the nitric oxide emission has been investigated with a swirl chamber diesel engine, by systematically changing some engine parameters. As the result, the following facts have been revealed : Some factors effective to flame cooling supress the nitric oxide formation at lower fuel-air equivalence rations, while they have less efect at higher ratios. In the latter range, the nitric oxide decreases with this ratio, which is attributable to the increase in the local fuel-overrich zone somewhere in the combustion space, and its decrease is largely dependent on the outflow of gas from the swirl chamber into the main chamber.

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By extending the five point approximation and the fifth order approximation presented by F. Freudenstein, an analytical method is established for the synthesis of a plane four-bar mechanism to generate approximately a desired founction over a finite interval. This method may be regarded as a general method in the synthesis where the input and output scale factors are specified in advance. Moreover, in order to reduce the structural error of the function generator designed by using this method, a new numerical procedure for respacing precision points is suggested on the basis of the tenth degree polynomial closely approximating the structuralerror.

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There has been need for the synthesis of multi-mobility and multilink mechanisms in order to generate some complicated functions or paths. So it is needless to say that the number synthesis should be performed to obtain an optimum kinematic chain. In this paper, a synthesis of spatial multi-link kinematic chains with one general constraint is carried out. First, the relationships between the mobility and the number of links and joints are obtained. The basic graphs are also obtained, which correspond to the chains with undefined direction pairs. Then, graphs which contain the kinds of edges coresponding to the axes of pairs are used for the synthesis. Moreover, the "distribution rule" and the "3-plane rule" are suggested for the selection of the pair directions. As the result, the censuses of kinematic chains with two loops and one or two mobilities, and ones with three loops and one mobility are presented.

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Some investigations about hydrodynamic lubrication of journal bearings using pseudo-plastic fluids were published in the previous papers by authors. In finite bearings, the velocity gradients in circumferential and axial directions are related respectively with the shear stresses in both directions, so that the velocity gradients in circumferen tial and axial directions correlate with each other. In this paper, a more general modified Reynolds equation including the effects of correlation is derived. Applying this theory to journal bearings, the bearing performance, such as pressure distribution, load capacity, frictional force and oil flow, is obtained. It is compared with the previous analysis neglecting the correlation. It is made clear that the effects of correlation are small in the case of a small "nonlinear factor" which is a dimensionless quantity indicating the non-Newtonian characteristics.

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The authors have investigated the causes of pitch errors in leadscrews during grinding and reported that the thermal deformation (expansion or shrinkage) of the workpiece during grinding is one of the most dominant causes, that is, in case of using spindle oil as grinding fluid, the temperature of the workpiece rises gradually as grinding operations are repeated and the accumulated pitch error often amounts to several ten um. It is the purpose of this paper to prevent such thermal deformation of the leadscrews during grinding. The method is to shower the oil, the temperature of which is controlled teh same as that of the room, on the workpiece all over the length. The results show that this method is very effective to prevent the thermal deformation of the workpiece. Furthermore, theoretical analyses are tried on the temperature distribution in the workpiece and on the limit of fluid flow rate to prevent thermal deformation. The theoretical analyses agree with the experimental results, and it is considered that this method is applicable to various grinding conditions.

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