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横振動均一細棒の等価回路網について(補遺) －等価回路網の一括表示－
Get PDF論文(Article)Recently, the authors have presented some reports on the equivalent electrical network for a transversely vibrating bar under various end-conditions. This paper is a supplement of the previous reports and shows the equivalent electrical networks of the vibrating uniform bar in case that the bar is restricted with four end-conditions (case 1 : free end, case 2 : simple support, case 3 : sliding support, and case 4 : fixed end) at the both ends, respectively. The equivalent networks for the pure stiffness-bars are also shown. These results are useful for analyzing a unit mechanical system and a composite one
音響接着剤の高温特性
Get PDF論文(Article)In order to find out good bonding materials available for the ultrasonic delay line operating under high temperature, the acoustic properties of six bonding materials which are rosin, sodium silicate, two kinds of polyrner adhesive and two thermo-compression metal bonds, were experimentally inverstigated in detail. Using an ultrasonic delay line which is composed of the Y-cut quartz transducer and the fused quartz, the insertion loss of bonding materials were measured as a function of temperature by means of the pulse-echo method. It was found tha the insertion loss of Pb-bonds is constant over a temperature range between 25 and 250℃ and the result obtained here indicates that Pb is one of the excellent bonding materials capable of operating under high temperature. Bonding techniques and the available temperature ranges of these materials are also reported
一軸配向したナイロン6の撚り及び圧延による結晶配向の変化
Get PDF論文(Article)The changes of cystal orientation in twisted or pressed nylon 6 mono filaments are studied using X-ray diffraction techniques. By twisting, nylon molecules are arranged parallel to the twist-line. Crystal lamellae are stacked along the twist-line while their surfaces are located in parallel to each other and parpendicular to the fiber axis. We consider that a lamella is divided to few blocks, and slipage between these blocks along b-axis occur. The rolled or pressed mono filaments have same different crystal orientation from twisted filament. A uniaxialy drown nylon 6 film is sheared parallel to orientation axis. The film shows particular orientation, and differ from orientation of twisted or pressed filament
流動層の流動性能について
Get PDF論文(Article)In this paper the influence of the structure and shape of the vessel and pipeline on the fluidization quality of fluidiged bed has been investigated. The quality of fluidiged bed was measured by means of fluidization index proposed by W. W. Shuster. The arrangements of the holes of the bottom plate of the bed and the length of the pipeline exercised a considerable infeuence on the quality of fluidization, and divergent type reaction vessels had better quality than ordinary cylindrical ones
擬だ円歯車の歯形面積の計算について
Get PDF論文(Article)In the roll forming of gears the cross-sectional area of the tooth is very important for design of blanks. The pitch curve, the tooth profile, thc tip ourve and the root curve of the pseudo-elliptic gear which closely approximate to the elliptic one are expressed by the equations in polar tangential coordinates. By using these equations the cross-sectional area of the tooth or the fillet is calculated
炭酸カドミウムの熱分解におよぼす雰囲気の影響
Get PDF論文(Article)The kinetics of the isothermai decomposition of cadmium carbonate in the presence of gaseous He, N_2, O_2, and CO_2 (10, 380 and 760mmHg) have been studied in the temperature ranges 270o to 330o (He, N_2 and O_2) and 350℃ to 400℃ (CO_2). In general, the decomposition curves at 270℃ and 280℃ are given induction period, indicating an autocatalytic reaction, but over the temperature range of 290-330℃ the induction period was virtually absent and the final decay period more pronounced. The decomposition rate was Lowered in the presence of He, N_2, O_2 and especially CO_2 than in vacuum. The rate equation that described the entire range of the decomposition was not found. The rate was described by using different rate equation for different stages of the process. Best results were obtained with degree of decomposition in an initial reaction, acceleratory period and decay period α = kt^m, 1-(1-α)^ = kt, and -log(1-α) = kt respectively. The activation energies in these cases have been found to be larger value than in ordinary chemical reactions, and the combined results of these experiments gave the following activation energies (per mole) in an atmosphere of He, N_2, O_2 and CO_2 at a pressure of 380mmHg: (a) 73.2-83.4 and 250.2 kcal for the induction period; (b) 47.3-53.0 and 159.9 kcal for the acceleration: (c) 66.9-75.6 and 228.5 kcal respectively
正方形および長方形わく組振動子を用いたメカニカル・フィルタの二・三の考察と実験
Get PDF論文(Article)This paper deals with electro-mechanical filters consisting of the vibrating frameworks which are driven piezo-electrostrictively. First, experimental results of the resonant modes of a square framework are described Electro-mechanical filters utilizing a pair of degenerating modes among them is discussed and it can be said that degenerating modes in such a vibrator are useful for an electro-mechanical filter. Secondary, a differential type filter which consists of the frameworks vibrating in the fundamental mode is discussed experimentally. In this filter, any spurious responces are not observed over the wide range of frequencies. Lastly, it is also described that the vibrator of a rectangular framework can be used as well as the one of the square framework mentioned above
工学力学系におけるエネルギー変換の幾何学的理論
Get PDF論文(Article)Abstract It has been pointed out through the geometrical research activities of RAAG that the geometrical expression for the performance of electro-mechanical and hydro-mechanical systems has the non-Riemannian character and it plays an essential role associated with the energy conversion in these systems. This suggests a possibility of constructing such geometrical theory that treats in a unified way the various energy conversions in engineering dynamical systems. In this report an attempt is made to study geometrically the problem of energy conversions on the basis of somewhat simplifying assumptions for the facility of analysis. Essential features concerning the energy conversion are grasped geometrically and the general principle for the physico-engineering application is obtained
側壁付着型素子の切換時間に及ぼす機械的振動の影響について
Get PDF論文(Article)Since fluidic devices have not mechanical movable parts, it is well known that one of the most distinguishing characters of these devices is that they are not influenced by mechanical vibration, but it can be thought that some effects are created by mechanical vibration so long as the behaviours of these devices depend on a dynamical motion. Then, in this paper, an experimental research is performed by vibrating some wall attachment amplifiers with pentagonal splitter to three directions , parallel to the main jet flow (Y-direction), parallel to the vented flow (X-direction), perpendicular to both the main jet and the vented flow (Z-direction). Air is used as working fluid and the frequency is varied from 0 to 50 Hz. From the results of this experiment, it becomes clear as follows; 1) The recovery pressure is not affected by mechanical vibration. 2) Switching time is affected by the direction of vibration. The effect of vibration to X- and Z- direct1on is comparatively remarkable in the case of a small quantity of both a supply flow and a control pressure, but it almost vanishes as the supply flow and / or the control pressure increases. Further experimental research is performed by changing the size of devices. It can be guessed from the results of this experiment that there are many differences between a large device and a small one
炭素鋼のバウシンガー効果に関する研究
Get PDF論文(Article)We made two kinds of experiments about this subject: for the first experiment, a number of structures of thin-walled cylindrical specimens of various carbon steels were made by heat treatment. From the stress-strain curves of these specimens drawn by the pendulum type torsion testing machine, the Bauschinger effect was estimated and the following results were gained. 1) In general, the less carbon is contained in the specimens, the less remarkably the Bauschinger effect is observed. Even in the annealed Flodin iron, the transient softening and the permanent softening are clearly seen when the order of 3 per cent shear prestrain is added. The Bauschinger effect of carbon steels depends not only on the carbon contained but greatly on other impurities. The Bauschinger effect decreases when the ferrite crystals of the specimen show an axial fibre structure. It can be said that the Bauschinger effect of carbon steels is made remarkable when the structure of the steels is complicated macroscopically or microscopically or both. 2) The permanent softening curves are higher than the stless-strain curves of the virgin specimens when the Bauschinger effect is less appreciable, but this is revealed just contrary when the Bauschinger effect is remarkable. This shows that the work-hardening occurs both in the pre-strained direction and in the reverse direction simultaniously, containing the causes of the Bauschinger effect in the reverse direction. 3) When the comparatively small prestrain, under 5 per cent, being applied to the specimens, the Bauschinger effect of carbon steels is linearlly proporitonal to the amount of prestrains. The rate of increase of the Bauschinger effect with the prestrain of specimens is proportional to the ”r” power (r > 1) of the coefficient of work-hardening of the last part of prestrain curves. 4) The Bauschinger effect of carbon steels can be partly removed by low temperature ageing but cannot be completely removed before recrystallization, and in the course of its removal, though the Cottrell atmosphere is formed, sharp yielding is not always observed if the Bauschinger effect is pronounced. In this case the preyielding often appears in the same deformation as that of prestrain. 5) The Bauschinger effect of specimens with spheroidized pearlite structure is revealed smaller than that of fully annealed same specimens. The difference between these two Bauschinger effects becomes more remarkable as the spheroidization of cementite is promoted. This is due to the fact that the coefficient of work-hardening of prestrain of the specimens with spheroidized pearlite is smaller than that of the fully annealed same specimens. 6) With the carbon steel with spheroidized pearlite, the Bauschinger effect is more difficult to remove by low temperature ageing under 200℃ than the same carbon steel of the annealed structure, in spite of the Bauschinger effect of the former being smaller than the latter as mentioned in (5). A sharp yielding in the reverse direction does not return to the pre-strained spheroidized carbon steel unless it is aged above 200℃. 7) For the annealed specimen, the activation energy obtained by the process of raising the lower yielding point till the first saturation, with the removal of the Bauschinger effect by ageing at around l00℃, was 19,000 cal/mole, and for the specimens with spheroidized pearlite, the activation energy of the same process with ageing at around 220℃ was 24,000 cal/mole. 8) When the constant amplitude of stresses ±t_0 is repeated, the permanent strain with the opposite sign to the prestrain is not observed in the specimens which show a little Bauschinger effect, but in the specimens in which the Bauschinger effect is remarkably shown, the permanent strain with the opposite sign presents itself.9) When ±t_0 is repeated, the width of the stress-strain hysteresis loop and the Bauschinger effect diminish remarkably at the second repition and then they diminish gradually to attain certain values after several repitions. But the effect of the prior deformation appears on the work-hardening and the Bauschinger effect of the subsequent stress-strain curves at least in the first few cycles of stressing. 10) Applying the prestrain, which is greater than the yield strain of the specimen, we repeated 10 cycles of constant amplitude of stress ±t_0 which were equal to the last stress of prestrain, and aged it. A sharp yielding returned in the positive direction. Though in the reverse direction the proportional limit rose somewhat, sharp yielding did not appear at all. If we begin with the same order of prestrain and ageing as above, but fail to apply the stress repetition, sharp yielding should appear in the reverse direction, and if the stress is repeated, the Bauschinger strain should be smaller than that of the pre-strained specimen as mentioned in (9). For the second experiments, the fully annealed cylindrical specimens of low carbon steel were given 4.3% and 28.8% compressive prestrains. From these cylindrical specimens, test pieces for compression tests and tension tests with the axes of various directions to the pre-compression were machined. From the stress-strain curves of these test pieces resulted from the experiments, the following results were gained concerning the anisotropy of the Bauschinger effect of pre-compressed cylinders. 11) The Bauschinger effects are closely related to the kind and magnitude of the macroscopic plastic strain of each direction given in the prior deformation. 12) The more prominent the Bauschinger effect is, the more slowly the transient softening curve rises, and the larger Bauschinger strain is attained at the last stage of the transient softening. 13) As to the anisotropy of yield stress obtained from the permanent softening curves, the experimental results of the author showed good agreement with the results reduced from Yoshimura-Takenaka's Strain History Theory of Plasticity. 14) Once born anisotropy of the structure resulted from prestrain of only a small order of 4.3 per cent can hardly be removed even if quite a large plastic deformation in a different direction to the prior deformation is given to the structure, and as the deformation proceeds, an anisotropic effect can be observed in the sectional form of the specimen, too. 15) From the experimental results presented above, it can be concluded that the Bauschinger effect is largely attributed to the microscopic ununiformity of the internal stress and strain produced by the prestrain rather than to the macroscopic residual stress produced in the prior deformation