result 3335 件
| JaLCDOI | 10.18926/15688 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_10_2_45.pdf |
| Author | Himei Toyoji| Nakanishi Senichiro| Komatubara Hitoshi| Kawata Sigeo| Onishi Fujio| Tabuchi Takashi| |
| Abstract | When a transformer is energized, the inrush of abnormally high magnetizing current may be noted for a short time until normal flux conditions are established. This may cause the failure of a protective relay, so many preventives are usually accepted for the purpose of normal relay performance. The authors, instead, now have tried to control the inrush current itself, by means of the soft starting method using two reverse parallel thyristors. In this paper, the method to control the inrush current itself, is presented by the soft-starting method using thyristors. The experimental results of this Method verifies the good controlability of the transient magnetic flux of a transformer and then the availability of the control of magnetizing inrush current in the cases of a single phase connection and a three phase one. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-01-27 |
| Volume | volume10 |
| Issue | issue2 |
| Start Page | 45 |
| End Page | 54 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307871 |
| JaLCDOI | 10.18926/15686 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_5_31.pdf |
| Author | Wada Tsutomu| Shimizu Akira| |
| Abstract | Though the Warren's fluidic counter has a very simple construction, the matching problems of the main jet supply pressure with the input pulse may take place and so there may be some working conditions under which this counter cannot work. Up to now, these matching problem have been hardly investigated. In this study the following things were systematically investigated : the static and dynamic characteristics of the memory and the control flip-flops with different geometric parameters, the behavior of the counter which are constructed by two of them, and finally the fow in the counter. The obtained results are as follows : (1) Under some clear and accurate conditions, the Warren's counter works satisfactory without any au iliary circuit. (2) In the control part, the input pulse flow don't reattach on any side wall, but branches into both output ports. (3) The necessary condition under which the Warren's counter behaves successfully is as follows : (1-2α)Q(i)>Q(ms), where α is the distribution factor of the control part, is the input pulse flow rate and is the switching control flow rate of the memory part. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1970-09-01 |
| Volume | volume5 |
| Issue | issue1 |
| Start Page | 31 |
| End Page | 35 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307883 |
| JaLCDOI | 10.18926/15684 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_10_2_15.pdf |
| Author | Shimamoto Yuzuru| Tanaka Yutaka| |
| Abstract | Results of calculations and experiments on the cold co-axial flow presented in this paper are summalized as follows ; (1) A theoretical expression method for co-axial flow field of two dimension is investigated to estimate more exactly the flow profile and the velocity gradient. (2) Measurements of mixing length were carried out for the confined co-axial jet flow. On the basis of measured data, inquiry is made for the propriety of the assumption proposed in the previous paper (1) that the mixing length may be expressed as a function of the minimum distance to the nearby wall. (3) Experimental inquiry was also done on the corelation between Lagrangian length scale and the mixing length. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-01-27 |
| Volume | volume10 |
| Issue | issue2 |
| Start Page | 15 |
| End Page | 24 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307794 |
| JaLCDOI | 10.18926/15673 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_4_57.pdf |
| Author | Takahashi Teruo| Kitamura Yoshiro| |
| Abstract | Although the stability of Newtonian liquid jet has been investigated experimentally and theoretically, many problems has remained unsolved. Especially, the stability of liquid jets in immiscible liquid systems has been little studied. Furthermore, one has to point out that the stability of jets may be influenced by the turbulence in the nozzle and the velocity profile. This work presents the experimental result about the effect of the nozzle length on the breakup length of liquid jets in the air and in the immiscible liquid, as the beginning of a systematic investigation of the influence by these factors on the breakup of jet. The dependence of the initial amplitude of surface disturbances on the nozzle geometry is presented for evaluating the effect of the nozzle length on the breakup length of laminar liquid jet in the air and in the immiscible liquid. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1969-09-01 |
| Volume | volume4 |
| Issue | issue1 |
| Start Page | 57 |
| End Page | 64 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307482 |
| JaLCDOI | 10.18926/15663 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_9_1_11.pdf |
| Author | Ohta Mutsuo| Nagai Makoto| |
| Abstract | Metastable values of electrical resistivity, P(E)' obtained during isothermal ageing differs in each experimental run even when the conditions of quenching and ageing were carefully kept constant. This phenomenon is considered to result from the competitive growth of G.P.zones. The range of the values of P(E) under the same conditions of heat treatments were examined, and the results obtained are as follows: (1) Metastable values of resistivity, P(E), during ageing at 70℃ after quenching from 300℃ were in rather narrow range. On the other hand, the width of the range obtained during ageing at 50℃ was wide. (2) When the specimens were aged at first at 70℃ until the maximum values of resistivity, P(M), being reached and then aged at 50℃ for long time, the metastable values of resistivity, PE*, were obtained. And the width of discrepancy of values of P(E)* was nearly equal to that of P(E) which was obtained in the case of isothermal ageing at 70℃ after quenching from 300℃. (3) It may be concluded that the width of discrepancy of values of P(E)* becomes smaller since the width of discrepancy of the number of G.P.zones for all experiments which can grow through competitive growth is made small by 70℃ ageing than that immediately after quenching from 300℃. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1974-07-20 |
| Volume | volume9 |
| Issue | issue1 |
| Start Page | 11 |
| End Page | 21 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307817 |
| JaLCDOI | 10.18926/15660 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_8_2_52.pdf |
| Author | Wada Tsutomu| Shimizu Akira| Dohta Shujiro| |
| Abstract | The dynamic behaviour of attaching jet with single side wall to step control flow and the switching proces of the bistable amplifiers were investigated experimentally and theoretically. In the experiments, a large scale model was used with water. The flow patterns were visualized by the tracer of polystrene granules and were recorded by a cinecamera. In the analysis, the quasi-steady proces was assumed. The results obtained can be summarized as follows: 1) The proposed analytical dynamic model of attaching jet explains well the dynamic behaviour of attaching jet with single side wall. 2) The process" of the opposite wall switching may be divided into three phases. 3) The analytical model of the opposite wall switching, including the formulation of the switching criterion, was proposed. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1973-12-26 |
| Volume | volume8 |
| Issue | issue2 |
| Start Page | 52 |
| End Page | 65 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307728 |
| JaLCDOI | 10.18926/15653 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_7_2_85.pdf |
| Author | Nakata Takayoshi| Ishihara Yoshiyuki| |
| Abstract | A new method for representing distorted wave forms is investigated. The method suggested by us is a modified vector symbolic method. It has been hitherto thought that the vector symbolic method cannot be applied to the distorted waves, because the rotating speeds of each harmonic vector are not identical. Representing the argument of the n-th harmonic vector by l/n times as large as the phase angle of the harmonic component, the relative positions of respective harmonic vectors are invariable wherever the standard vector is put, and the wave shape can be deduced from the vector diagram. We found various correspondences between the wave forms and the vector diagrams. Therefore, the wave shape can be estimated from the vector diagram, and the mutual relationships between two wave forms can also be known. In electric or magnetic circuits, the causes of distorted wave forms are in general obvious. Therefore, there are very often the fixed relationships between the amplitudes and phase angles of the harmonics. Further, in polyphase a.c. circuits, there are often the fixed relationships between corresponding harmonics in the wave forms of the respective phases. When the wave forms of those circuits are discussed, the new method investigated in this paper may offer a useful key. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1972-10-13 |
| Volume | volume7 |
| Issue | issue2 |
| Start Page | 85 |
| End Page | 88 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307535 |
| JaLCDOI | 10.18926/15635 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_4_35.pdf |
| Author | Kaneda Yasuhiro| Osaki Hirokazu| Kikuchi Susumu| |
| Abstract | Insuring fast and precise human operation is one of the engineering requirements in the developing civilization. Some man-machine system, when any operator is exposed himself to some kind of vibration, he may not perform his operation in good conditions. Then one of the interferring factors, there is a fatigue caused by vibration. In this study, subjects sit on the chair which was set on the vibration table, and were shaken vertically for some given times, then were measured whether the fatigue occured or not by flicker friction tester. Flicker patterns were analyzed according to each vibration-condition, then the authors knew that the fatigue was occured by vibration. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1969-09-01 |
| Volume | volume4 |
| Issue | issue1 |
| Start Page | 35 |
| End Page | 38 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002308023 |
| JaLCDOI | 10.18926/15621 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_3_137.pdf |
| Author | Himei Toyoji| Fujitsuka Takeshi| Inoue Jyunichi| Komatsubara Hitoshi| Kadowaki Masahiko| |
| Abstract | The measurement of the dissipated energy in switching-off has been attempted to make clear the function of spark on electric contacts, which may unfortunately cause the combustible gas, such as propane gas etc, to catch fire and result in fire accidents. By utilizing the "Memoriscope" has been the meaurement carried out and the feature of this method is to provide the information on not only the amount of dissipated energy involved in one action but also on the trace of its instantaneous power which can affect catching fire delicately. Presented in this paper are the discussion of this measuring method and the measured results which are obtained experimentally in order to investigate the dependence of the energy dissipation on variety of contacts, contacts' deterioration and circuit arrangements. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1968-09-01 |
| Volume | volume3 |
| Issue | issue1 |
| Start Page | 137 |
| End Page | 142 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307412 |
| JaLCDOI | 10.18926/15614 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_3_101.pdf |
| Author | Hirai Taketsugu| Takahashi Katsuaki| |
| Abstract | Potential sweep voltammetries of Na(2)O·SiO(2) and Na(2)O·2SiO(2) at 730-1200°C were performed with the stationary platinum wire electrode and with the sweep rates of 40 and 120mV/sec. Although current-potential relation of Na(2)O . SiO(2) at 1200°C gave stationary S-shape pattern, those of the rest were transient modes with hysteresis. From the voltammetric considerations, a reversible oxygen electrode process where diffuion of free oxygen anion or silicate anion may be a rate-determining stage was tentatively proposed. Approximate estimations of decomposition voltage supported that a sole reaction process such as the decomposition of Na(2)O or indirect decomposition of SiO(2) in the melt was most probable. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1968-09-01 |
| Volume | volume3 |
| Issue | issue1 |
| Start Page | 101 |
| End Page | 105 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307459 |
| JaLCDOI | 10.18926/15603 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_3_39.pdf |
| Author | Ohta Matsuo| Hashimoto Fumio| Tanimoto Tadashi| |
| Abstract | Al-Zn, Al-Ag and Al-Cu base ternary alloys were studied by measurement of electrical resistivity. An approximate methods to estimate the binding energy between an atom of a third element and a vacancy was derived. The binding energy between a vacancy and an atom of Cu, Ag, Au, Be, Ca, Cd, In, Si, Ti, Ge, Zr, Sn, Pb or Mn was estimated to be <0.23, 0.25,> 0.35, 0.28, 0.27, 0.32, 0.39, 0.28, 0.30, 0.33, 0.33, 0.43, >0.38 or <0.23 (±0.05) eV, respectively. The results may be summarized as follows: (I) The ratio of the time required to reach the maximum electrical resistivity in isothermal aging curves of the Al-Zn-X or Al-Ag-X ternary alloy to that in the Al-Zn or Al-Ag binary alloy may be inversely proportional to the ratio of the concentration of vacancies bound to Zn or Ag atoms immediately after quenching in the ternary alloy to that in the binary alloy. And also the ratio of initial rate of clustering for AI-Cu-X ternary alloy to that in the binary alloy may be inversely proportional to the ratio of the concentration of vacancies bound to Cu atoms immediately after quenching in the ternary alloy to that in the binary alloy. It is possible to deduce the binding energy between an atom of X element and a vacancy using this relations. (2) The effect of the valence of the solute element on the binding energy between an atom of a third element and a vacancy was remarkable. (3) The effect of the radius of an atom of the solute element on the binding energy is also observed, but this effect is smaller than that of the valence. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1968-09-01 |
| Volume | volume3 |
| Issue | issue1 |
| Start Page | 39 |
| End Page | 50 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307944 |
| JaLCDOI | 10.18926/15602 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_3_31.pdf |
| Author | Wada Tsutomu| Shimizu Akira| |
| Abstract | This study is concerned with a developed method for obtaining the quantitative relations between the input or output characteristics and the geometric parameters of the wall reattachment fiuidic devices. In this report, it is shown analytically and experimentally that the characteristics can be represented by the functions, dependent on the geometric parameters only, with non dimensional quantities, if the Reynolds number at the main jet nozzle is sufficiently large. Accordingly, the quantitative relations of the geometric parameters may be analyzed more easily. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1968-09-01 |
| Volume | volume3 |
| Issue | issue1 |
| Start Page | 31 |
| End Page | 37 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307757 |
| JaLCDOI | 10.18926/15593 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_2_133.pdf |
| Author | Misaki Takayoshi| Okamoto Takuji| |
| Abstract | This paper describes a method of hybrid computation for the problems including the function x(n). And the greater part of it is devoted to the considerations of the linkages between the analog and the digital for the function x(n). Here the function x(n) appears frequently in the form of x(2) or x(4) in the industrial problems. As is well known the function x(2) is the characteristic included in fluid-flow problems, and x(4) is in heat-radiation problems. The weak points of analog computation for these characteristics are in accuracy and stability, but can be compensated by making use of digital computer for these parts. In the industrial uses the exclusive digital computer is more convenient than the general-purpose one. Here the relative error of analog computation, the linkages, the number of the digital elements and their relationships are considered at the same time and as the results the reasonable method of hybrid computation is obtained. That is, the exclusive digital multiplier with a compressor and an expandor is found reasonable. Its design considerations are described in details, but it is the basic idea among others that the characteristics of the compressor and the expandor are determined so that the relative error of the signal appearing at the output of the latter may be constant and as the results the necessary and sufficient number of the digital elements may be decreased. And in practice these characteristics are also realized approximately by a group of the straight lines through the origin. Finally the reduced rate of the digital elements and the optimum condition of the approximation are illustrated together with an example. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1967-04-01 |
| Volume | volume2 |
| Issue | issue1 |
| Start Page | 133 |
| End Page | 137 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307842 |
| JaLCDOI | 10.18926/15581 |
|---|---|
| Title Alternative | SEASONAL DIFFERENCE IN THE EFFECT OF THERMAL BATH ON BLOOD CATALASE. |
| FullText URL | 006_046_048.pdf |
| Author | Oshima, Yoshio| |
| Abstract | Blood catalase level in healthy rabbits was measured before and after thermal bath of Misasa in January, May, July and September. And the differences in the effect of thermal bath between the four seasons were investigated. Blood catalase level in rabbits proved to be highest in winter and lowest in September. A slight fall in blood catalase level was recognized an hour after the thermal bath at 42℃ for five minutes. And in September the degree of fall seemed to be slightest and the recovery soonest. |
| Publication Title | 岡山大学温泉研究所報告 |
| Published Date | 1952-03 |
| Volume | volume6 |
| Start Page | 46 |
| End Page | 48 |
| ISSN | 0369-7142 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002307946 |
| JaLCDOI | 10.18926/15575 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_2_43.pdf |
| Author | Takahashi Teruo| Fujita Kozo| |
| Abstract | In this report, the analogies of the maximum allowable liquid and gas velocities in various countercurrent gas-liquid contactors of column type are considered analytically. That is, by plotting the flooding points of various columns in a gas-liquid separated coordinates, the similar curves have been obtained in each column. Because the difference of these curves is due to the shape of each column, the difference of each shape must be corrected and evaluated as a ahape factor. Then, by containing this factor in coordinate variables, various flooding points in each column may be correlated by a single curve. If this correlation curve is used, the flooding velocity can be estimated easily, and the maximum allowable liquid and gas velocities in these countercurrent contactors of column type can be compared. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1967-04-01 |
| Volume | volume2 |
| Issue | issue1 |
| Start Page | 43 |
| End Page | 49 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307818 |
| JaLCDOI | 10.18926/15559 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_1_134.pdf |
| Author | Ohta Mutsuo| |
| Abstract | Polycrystalline specimens of Al-30wt % Ag and Al-30wt % Zn alloys, which were quenched into water from the temperature of solution heat treatment, were annealed at L.T. aging temperatures or reversion temperatures so as to make them contain zones of nearly equal radii for each alloy and various concentrations of solute element in zones. These specimens were cold rolled exactly to 50%, and then annealed at L. T. aging temperatures for varying time. The state of zones and precipitates were investigated by X-ray small-angle scattering photographs. The results obtained were as follows: (1) The precipitation ofγ'-phase began earlier in the specimens of Al-Ag alloy annealed at L. T. aging temperature before cold rolling than in those specimens annealed at reversion temperatures before cold rolling when annealed at L. T. aging temperatures after cold rolling. (2) The rate of precipitation of Zn solid solution in Al-Zn alloy did not depend upon the annealing temperature before cold rolling when cold rolled specimens were annealed at L. T. aging temperature. (3) In Al-Ag alloy, the rate of disappearance of G. P. zones at L. T. aging temperature depends mainly upon the annealing temperature before cold rolling. On the other hand, in Al-Zn alloy, the rate of disappearance of G. P. zones at L. T. aging temperature does not depened upon the annealing temperature before cold rolling. (4) These results may be explained without contradiction considering the relation of structures between matrix and precipitates and the deformation stacking faults. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1966-03-31 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 134 |
| End Page | 137 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307180 |
| JaLCDOI | 10.18926/15502 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_24_2_79.pdf |
| Author | Sato, Yoichiro| |
| Abstract | In asynchronous arbiters, failures may happen, caused by metastable operations. The purpose of this study is to derive a formula to estimate such failures in a ring arbiter as mean time between failures (MTBF), under the condition that incidences of requests issued in all devices are different from each other. The operation of the arbiter is formularized by a markov chain. This chain is used to decide the probability at which each of possible failures contributes to MTBF. The sum of such probabilities gives the MTBF which can be represented as a sum of a finite number of terms. As an example, MTBF of a ring arbiter composed of 3 cells is shown. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1990-03-29 |
| Volume | volume24 |
| Issue | issue2 |
| Start Page | 79 |
| End Page | 87 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307486 |
| JaLCDOI | 10.18926/15499 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_24_2_49.pdf |
| Author | Mori, Chuji| Machida Ken-ichi| |
| Abstract | Distance measurements have been more and more easy and accurate to carry out, and it is expected that distance mesurements may provide rather accurate results than angle measurements. Under these circumstances, caracteritics of errors in typical trilateration nets are investigated. The nets investigated are as follows: From single row of chains to pranimetrically extended nets in figure, open and closed networks with respect to external constraint, and with and without as to internal constraint. Computations are performed by use of the method of condition equations, and behaviours of error propagation and errors of coordinates of stations in the nets are shown in case of typical nets. For example, effects for decrease in error by composing a double row of chains and by enforcing external constraints are explained. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1990-03-29 |
| Volume | volume24 |
| Issue | issue2 |
| Start Page | 49 |
| End Page | 65 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307544 |
| JaLCDOI | 10.18926/15466 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_24_1_1.pdf |
| Author | Yoshida, Akira| Ohue, Yuji| Fujii, Masahiro| |
| Abstract | To clarify the effects of a drive system lubricant additive upon rolling fatigue of rollers manufactured from carburized and hardened steel, three types of oil were used as lubricants: one mineral base oil and the other two mineral base oils to which an S-P additive package and ATF additive package were added, respectively. These specimens were tested for sliding/rolling fatigue and examined for failure on the surface, rolling fatigue strength, and other properties. Roller surface temperatures and inter-roller frictional coefficients were found scarcely affected by the type of oil used. Irrespective of the difference in oil type, failure on the surface was found to be entirely spalling attributable to cracks generated in the subsurface. The depth at which spalling cracks had taken place was found nearly coincident with the depth at which a ratio of reversing orthogonal shear stress to hardness had amplitude A(Tyz/Hv) maximized. These depths were larger as Hertz stress became more prominent. Nevertheless, they were found hardly affected by the type of oil. Although rolling fatigue strength did not show a significant difference dependent upon the type of oil, it may be said that fatigue life would be somewhat negatively affected by an extreme pressure coated film with a content of sulfur and phosphorus. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1989-11-29 |
| Volume | volume24 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 12 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307588 |
| JaLCDOI | 10.18926/15447 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_129.pdf |
| Author | Taniguchi, Takeo| Hirose, Sohichi| Ouchterlony Finn| Nakagawa Kohji| Miyaji Akihiko| Fukuoka Yasufumi| |
| Abstract | The testing method of rock toughness is proposed by the international society of rock mechanics (ISRM), but the results may be influenced by the test pieces, and the details of the crack propagation and the stress intensity factors are not clarified through the testing. Also the experimental test requires tedious works for the preparation of test specimen and economical responsibility. The present study aims to simulate numerically the rock toughness testing which is proposed by ISRM. For this purpose, the authors propose a numerical method which can simulate the experimental testing, and they show the propriety of the proposed method by comparing the results with the experimental and other numerical methods. At the same time, they clarify the details of crack propagation behaviors in rocks, and show the change of the stress intensity factors. The proposed method is based on the displacement-type finite element method, and several techniques are introduced to obtain accurate solution of the mechanical behavior near the crack-tip area. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 129 |
| End Page | 138 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307126 |
