本報告では、断面の変化する平面曲線棒に対し、その曲率中心方向に一般動荷重が作用する場合の動的応答について解析した。具体例として、断面の変化する両端固定対称形半だ円弧棒にステップ状の集中衝撃荷重が作用する場合の変位および曲げモーメントの時間変動を求め静的な値と比較した。さらに、断面の変化や衝撃荷重の作用点の変化による応答の変化を明らかにした。

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はつ(撥)弦の減衰特性を明らかにするために、単純支持ばりによって二点支持された弦の減衰特性を実験的、理論的に検討した。その結果、ある程度強く、弦とはりが連成する系の固有振動数がはりの固有振動数に近づくとき、弦の減衰は大きくなること、固有振動数がはりの高次モードに近づくほど、弦の異常な減衰は生じにくいこと、およびはりの減衰係数が小さいと弦とはりの間にエネルギのわたり歩きが生ずることなどが明らかとなった。

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スクリュ圧縮機のロータに作用するガストルクを面積モーメント法によって求め、ロータのかみあい周期を基本波とするフーリエ級数に展開し、雌ロータに作用するガストルクが負となる運転条件があることを明らかにした。さらにスクリュ圧縮機駆動系のねじり振動および動的角度伝達誤差を測定し、回転次数比分析を行った。両者を比較し、運転条件とねじり振動特性によって歯面分離振動を起こすことを確認した。

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トルク励振による不つりあい曲げ振動を一般的な弾性ロータに対して解析すると共にトルク励振によるつりあわせ理論を提案した。振動数γのトルク励振により振動数ω±γの不つりあい振動が生じ、その振幅はねじり振動振幅で変調される。つりあわせ理論では本法の特徴を生かし、両端支持ロータのQ値を測定するモードつりあわせ法を論ずると共に、最適なつりあわせ面に関しても考察を加えた。

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自由支持された正方形の平板にフォーストランスデュ-サ付の球を衝突させ、衝突時に球と平板の間に働くパルス状の接触力、平板の振動、平板の近傍および平板から離れた位置における衝突音を同時に測定し、衝突音の発生機構を四段階に分けて研究した。球の種類、衝突速度を変えて実験し、各段階で対応する測定量について周波数特性を求めて解析した。その結果、この場合の衝突音の発生機構を定量的に解明することができた。

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一枚の平面鏡を用いることにより、従来の多方向からの写真計測法と同等の能力を持ち、より簡単に三次元座標を計測できる写真計測法を開発した。そして、本計測法の誤差解析を行い、理論的にその測定能力を明らかにした。さらに、この測定法を用いて、空間運動物体(空間四節リンク・放物体・人体上肢)の運動諸量を求め、本計測法の運動測定能力を評価した。

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超音波によるボルト締結体の二次元締付圧力分布測定装置を試作した。本報告では、この装置の性能を他の測定方法との比較実験により明確にするとともに、具体的な応用例として、各種結合面形状を有する単一ボルト締結体の締付圧力分布の測定を行っている。その結果、結合面形状が締付圧力分布および圧力作用範囲におよぼす影響を明らかにし、さらに、締付圧力分布においてもモーメントイメージ法が成立することを確認した。

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鋼歯車とかみ合うナイロン歯車の歯形変化の防止法として本報では鋼歯車に歯形修整を施すことを提案すると共にその適正修整量を実験で求めた。その結果、鋼歯車の歯形修整量Δa(分)は次式でよいことがわかった。Δa=ζ(T_c・T/0.98b)+ξ ζ:歯車変化の変化値[(分)/(N・m/m)・s]、T_c:ナイロン歯車の歯のかみ合い周期(秒)、T:ナイロン歯車に作用するトルク(N・m)、b:歯幅(m)、ξ:歯形変化の基本値(分)

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歯車用潤滑油の耐ピッチング性能を、二円筒試験機により評価した。テストローラとして、炭素鋼およびCr-M₀鋼を用い、すべり率-18%に設定し、テストローラの硬さ、表面粗さ、接触応力を変えて実験した。この結果次のことがわかった。(1)潤滑油の粘度増加、およびM₀系潤滑油添加剤の作用は、耐ピッチング性能の向上に有効である。(2)磨耗が進行する実験条件下では、見かけ上ピッチング寿命が延長する。

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鼓形ウォームギヤは、ウォームの歯面が複雑な自由曲面のため、関係位置の調整、ホイールの切削、効率変動など、未解決の問題を抱えている。著者らはこれらの問題を歯当たりの観点から解決しようと試み計算、実験の両面から研究を行った。そして実用の数値の鼓形ウォームギヤについて、計算による歯当たり解析を行い、実験によって関係位置の変位と効率、油温の関係を調べた。また、鼓形ウォームギヤのCADシステムへの見通をも得た。

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確定的な場合には十分検討されている歯車系の跳躍現象について角度伝達誤差と振動との結びつきという観点から伝達誤差を確率過程と見なした場合の強制振動の時にも果して発生しうるものなのかどうかという事を中心に考察した。まず二乗平均値の意味で発生の有無を調べついで簡略化した形で密度関数について検討した結果狭帯域形の伝達誤差に対しては跳躍を生じ密度関数の分離という形を呈し広帯域の場合は消滅する事が明らかとなった。

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平歯車において歯先修整量がスコーリング限界荷重、摩擦損失および比磨耗量におよぼす影響を、FZG歯車試験機を用い、二種の歯形を用いてまとめた。標準歯車か、それに近い歯形の場合は、駆動・従動の両歯車の歯先を修整することにより最もよい負荷特性が得られたが、従動歯車の歯先だけを修整することにより、負荷特性は改善されず、逆に低下することがわかった。また一方に大きく転位した歯車の場合は傾向は、また別の形であらわれた。

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接触面表面温度が、油膜から供給される熱量と周りに放散される熱量、本体中へ伝達される熱量との差によって決められるという微分方程式を作成した。歯車運転試験、ローラ試験による温度測定結果は定量的にこの微分方程式の解とよく一致した。この微分方程式の係数によるスコーリング発生の危険度を示す指標値を定義した。歯車によるスコーリング発生試験はこの指標値の妥当性を裏づけるものであった。

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かさ歯車歯面をエンドミルで近似度良く成形できる前報の歯切法による歯車の、歯たけと歯厚の比はその内端と外端で著しく異なる。歯の曲げ強さを考慮し、この比をほぼ一定に保ち、しかもエンドミルで近似成形する歯切法を新たに提案した。そしてこの方法で軟質機の歯車を数値制御歯切し、歯面の共役性が極端には悪くないことを確かめ、さらに歯車の歯元角の関係を明らかにし、歯面の共役性を理論的に解明し、その改善方法を検討した。

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かさ歯車の歯形は歯すじに沿って変化する。この歯形を軸断面が直線のエンドミルで創成しょうとすれば歯すじに沿う工具の行程数は多くなる。ところが、かさ歯車の外端歯形をエンドミル刃形とし歯形に近い工具刃形部分で創成すれば行程数は大幅に減らせる。この考えによる歯切法を提案し、その諸問題を検討した。例えばこれら両刃形による歯面創成残量の比がピッチ円すい角γ=15°で約1/20、γ=75°で1/7であることを確認した。

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振動を加えながら金属(99.7%Al)を凝固させ、高温のまま成形する方法を試みたところ、微細で均質な結晶組織をもつ素形材が得られた。凝固過程での結晶組織の微細化・均質化がこの素形材を得る上で最も重要であることがわかった。また成形後得られた組織の機械的性質がすぐれていることを確認した。従って本方法のような省エネルギ・省工程的な方法で高品質の素形材を得ることが可能であることがわかった。

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まがりばかさ歯車の切削において、切削力を知ることは、安定な切削条件の選択や、歯切盤の設計にとって非常に有効である。そこで本論文では、歯切りを行う際の任意の創成位置の切削力を特別なアタッチメントを作って測定し、さらに計算によりその時の切削断面積を求め、比切削抵抗の変化を調べた。その結果、比切削抵抗は旋削などとは異なり一定にはならず、創成位置によって変化することがわかった。

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多目的最適化問題に対する従来の対話形解法においては、いずれも解析者が意思決定者に数値情報を提示し、回答をうる。意思決定者の選好構造に関する正確な回答をうるためには、情報をわかりやすい形で示す必要があり、その一つの有効な方法が、情報の視覚化である。解析者の提示する情報をグラフィックを用いて図、グラフによって表示した計算機援用対話形解法を構成し、ディーゼルエンジンの多目的最適設計問題に対する対話実験を行う。

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This paper deals with a theoretical analysis of damping ratio for a vibrating circular rod in a two-phase air-water bubbly fluid, showing a good agreement between both theoretical and experimental results. The two-phase fluid model presented here assumes the liquid-phase medium be incompressible, containing a circular rod, and mass- and rigidity less circular "air columns". In the analysis for motions of these circular columns in the liquid, damping matrix is assumed to be diagonal, and the damping ratio is evaluated. The theoretical values are compared with the experimental ones, giving a good agreement.

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To avoid resonance of steam turbine blades during operation, it is necessary that the prediction method for natural frequencies of blades is established. Therefore, the calculation method of the natural frequencies was developed for the structure in which blades on the entire disk circumference was binded. It was found that five natural frequencies was existed within the range below 500 Hz in calculations of natural frequencies of a single blade for a turbine. Noticing the vibration of the direction in which moment of inertia is small at the middle between blade root and blade tip, we can show systematically vibration characteristics for these natural frequencies. Besides, the relation between the natural frequencies of the all banded blades and that of a banded group of several blades and variation of the natural frequency to vary blade dimension are also discussed.

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This paper is concerned with coupled vibration between flexible bladed disks and flexible shafts in the application of the Finite Element Method. since a bladed disk is considered as a periodically symmetric structure, it is enough to analyze one periodic substructure of a bladed disk by the use of the Cyclic Symmetry Method. In this paper, it is assumed that only one nodal point at the center of a bladed disk is connected with one nodal point of a shaft. The followings are known through this study. (i) Natural modes of zero nodal diameters generated on a bladed disk are coupled with longitudinal and torsional vibration of a shaft. (ii) Natural modes of one nodal diameter generated on it are coupled with only lateral vibration of a shaft. (iii) Natural modes of more than two nodal diameters generated on it are uncoupled with vibration of a shaft completely.

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This paper reports influence of differences in natural frequencies and damping of axial fan on resonant amplitudes of engine orders. The analytical results can deduce several following new characteristics of blade vibration. (1) Each blades can not vibrate by itself, but influence each other through a hub element. The stiffness of hub does not make much difference in the coupled vibration effect. (2) The maximum amplitudes of engine order resonances are influenced more sensitively by differences of blade natural frequencies than by those of damping. (3) The distribution of differences in blade natural frequency does not change significantly the maximum amplitude at engine order resonance. (4) The maximum amplitude ratio can not be over about 1.5 in comparison with the case of uniform blades, even if considering any difference of natural frequencies.

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The 1/2-th sub-harmonic oscillations of a system with a Duffing type restoring characteristic are investigated by making use of a harmonic balance method, under the condition that both the periodic exciting force (e, g., an unbalancing force) and the constant force (e.g., gravity) are operative. In contrast with the preceding paper⁽¹⁾, the restoring characteristic of this system is assumed to be a soft spring. As a result, the phenomena of these vibrations are considerably complicated and also extremely different from the same kind of vibrations in the hard spring system⁽¹⁾. However, the occurrence of the 1/2-th sub-harmonic vibrations in this system is possible similar to the hard spring system, even if the constant stimulating force approaches zero.

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The optimum vibration control of multi-dimensional vibration system as in the case of a transportation vehicle is considered impossible if the control makes use of only passive elements like a spring and damper. This paper proposes a scheme to materialize an optimum vibration isolation system by the employment of active elements which control the pneumatic pressure of the air springs. The design principle is to calculate the optimum feedback transfer functions minimizing the accelerations of vertical, rolling and pitching mode within the predetermined stroke of the air springs when the system is given the stationery random vibration. some experimental results are given following this principle.

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In order to control the mechanical vibration of multi-degree of freedom system, this paper proposes the practical application of dynamic absorbers and a new approach for these design. It is widely known that the design method for a dynamic absorber to one degree of freedom system has already been established. However, there still remains a problem how to constitute suitably the dynamic absorbers to the multi-degree of freedom system. The principal point of the design method proposed here is in exactly estimating equivalent masses and these locations on the each vibration mode, after decoupling the vibration system in modal domain. The locations are selected as the settling point of dynamic absorbers, and the masses are used as an essential design parameter. The effectiveness of the design method is demonstrated by controlling the undamped vibration of a three degree of freedom system using three dynamic absorbers.

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To confirm the availability of the design method for dynamic absorbers to the miltidegree of freedom systems proposed in 1st report, this paper shows that the first three resonances of a cantilever beam structure with negligible internal damping are suppressed effectively by three dynamic absorbers which are designed by using the method. First, the suitable locations to install each dynamic absorber and the equivalent masses at these locations are estimated by appling the transfer matrix method. After forming a complex transfer matrix for the dynamic absorber, the complex transfer matrix method to calculate the frequency response of the beam structure with three dynamic absorbers is shown. by means of both theoretical and experimental analysis, finally, it is found that the use of dynamic absorbers has great potential value in reducing the resonant vibration of such beamlike structure.

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The new type of impact damper consists of a bed of granular materials moving in a container fixed to the primary vibrating system. The problem is to determine the characteristics of the impact damper for reducing the vibration of the system to a prescrived value. This report treats with the indicial response of the damper i.e. the damping characteristics of free oscillations from initial displacement of the vertical and the horizontal vibrating system. Experimental models were tested and numerical analyses were developed to find the damping characteristics for several values of mass ratio and clearance. Results from numerical analyses agreed favorably with experimental tests.

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This paper proposes a method to estimate the magnitude of the error caused by the approximation of the substructure synthesis method for the time history analysis where coupling effects are treated as constant during each time step, and examines the accuracy through calculations for several linear vibration modes, which are divided into subsystems and connected by spring. Accuracy is evaluated in term of the distorsion of the eigenvalues by the approximation. It is found that the accuracy is represented by the one parameter consisting time step, stiffness of coupling, and mode shape coefficients.

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Buckling and postbuckling behavior of a flexible clamped-hinged pipe which is hanging vertically, due to an internal flow, are examined theoretically and experimentally. The equations of the axial fluid flow and the transverse motion of the pipe, which are coupled through the nonlinear terms, are derived. Assuming that the deflection of the flexible pipe is infinitesimal, the critical velocity of fluid, above which the pipe buckles, is determined from those equations. Under the super critical condition, the stable equilibrium solution with finite amplitude is analytically obtained. Also the numerical solution, which is available for large deflection, is obtained. This solution agrees good with the analytical solution in case of small but finite deflection. Furthermore the experiment was performed by using a pipe model conveying water. The experimental result is shown to be in good agreement with the theoretical one.

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The non-stationary response of an elastic circular cylindrical tank partially filled with liquid to a simulated earthquake excitation is investigated. The earthquake acceleration is modelled as an amplitude modulated non-white random process and the mean and standard deviation responses of liquid surface displacement and tank wall deformation are analyzed by the moment equation approach. The nonlinearity of liquid surface oscillation is considered in the response analysis to a long period earthquake excitation and the numerical results obtained have revealed the importance of nonlinear analysis for evaluating seismic safety of liquid storage tanks.

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Dynamic system identification technique, whereby the structural nonstationary behaviour can be estimated, is proposed and examined from the practical viewpoint. First, structural parameter estimating method with the aid of auto-regressive model fitting proposed in the former report is further developed to the system in which its natural frequency and damping variate with time. Such a structural nonstationality is represented as a kind of trajectory on the complex sτ-characteristic plane which is obtained through z-trans formed plane. Numerical examination is carried out for the practical model such as a liquid storage tank in which stored amount should variate with time. Second, proposed technique is applied to the inelastic structure system. Equivalent linealization is introduced in order to estimate equivalent damping which associates with inelastic energy absorbing effect. After linealization, it is made clear that inelastic behaviour can be also expressed on the linealized sτ-characteristic plane. Obtained results are investigated by comparing the results through statistical linealization method and the inelastic response analysis.

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Important mechanical systems installed on nuclear power plants and other industrial facilities must be designed not to lose their performance during and after destructive earthquake excitations. In this paper, reduction of the first excursion probability of such mechanical systems with inelastic restoring force-deformation relation is examined. First, the first excursion probability of inelastic mechanical system is estimated from experiment using stationary random noise as input. Next, relation between restoring force and deformation is identified from simulation technique using hysteresis loop obtained from experiment. Next, effectiveness of reduction of the first excursion probability for mechanical systems subjected to earthquake excitation is examined by using non-stationary artificial time histories. Finally, obtained results are examined by theoretical technique using equivalent linearization method. It is concluded that the first excursion probability of inelastic mechanical system is less than that of elastic system.

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This paper deals with the construction of an analytical model of a vertical mechanical structure subjected to 2D seismic excitation and numerical vibration analysis for 2D sinusoidal and stationary random excitations. Results indicated three kinds of vibrational resonance phenomena, i.e., (1) regular resonance to horizontal excitation. (2) parametric resonance to vertical excitation, and (3) combined resonance to simultaneous horizontal and vertical excitation.

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This study analyzes the role of human factors in the steering system of two-wheeled vehicles, using equivalent mechanical elements as the first step toward systems analysis of the man/vehicle relationship. This steering system, including human factor, has approximately one torsional degree of freedom. These factors can be obtained by the frequency response of the steering bench model with rider. First, the reproducibility and linearity of human factors are checked. Then, the human factor values are shown, changing accordingly as the rider's handle grip and press forces vary. Finally, the equation for two-wheeled vehicle motion is derived, and the result of these calculations makes it clear that human factors play a major role in the behavior of two wheeled vehicles.

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A "Cup and Ball" game is demonstrated by the manipulator (AMY-3), which has three degrees of freedom and whose motion is restricted to a vertical plane, using dynamical control and dynamical processing of visual information. In this process, a very simple algorithm is proposed for searching the center of the moving white ball, by which pictures obtained from a TV-Camera are processed in a very short time. Moreover, combining vision system and motion control system, the servo system is constructed whose reference inputs (desired trajectory) are adjusted by visual information in real time, and then the availability is shown experimentally.

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The quasi-static vibratory analysis of a rotor supported by ball bearings is presented. The system is an ideal ball bearing in which the inner ring moves in the radial plane with two degrees of freedom under a constant radial load. The motion of the inner ring centre due to ball revolution, which has been known as the Perret-Meldau problem since the 1950s, is analysed in detail. The results show that the inner ring motion has complicated features and changes drastically with the design and operating conditions. All computed results are arranged in a numerical table and in charts. They represent a complete package for the estimation of the magnitudes and characteristics of the inner ring motion, and may be used in the design process to examine the rigidity, the critical speed, and vibratory nature of a rotor.

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