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製品の応力や固有振動数などを製品ができる前に予想し許容応力外の場合に対策を立案するために、理論モード解析を使いファンケースとフランジの解析を行う。本研究では、ファンケースとフランジ、シロッコファンの強度・振動特性を求め解明する。, For the product to clarify the stress and the character frequency etc. of the product before it is possible to do and to work over measures and to solve it in a permissible stress etc. it, the use fan case and frange ..theory mode analysis.. are analyzed. In this research, it clarifies for strength and the vibration characteristic of fan case, the flange, and the Sirocco fan.

現在ゴルフクラブの性能は、NPO(国際パークゴルフ協会)による規格が「基準クラブとの比較における飛距離の差は±3%以内であること」と定められているため、飛距離の面では差別化が図れない。従って近年、ゴルフを気持ちよく楽しむために、ゴルフクラブのスイング音、ボールとの衝突音が製品化に問われ始めている。本研究では後者を取り上げた。, The discrimination can not be attempted concerning the flight-distance, since the standard by NPO (the international park golf association) has determined the performance of the golf club as "that the difference of the flight-distance in the comparison with the standard club is within ±3%" at present.Therefore, in order to enjoy the golf for the good feeling recently, it begins to be asking swing sound of golf club and collision noise with the ball for the merchandizing. In this study, the latter be taken up.

実験周波数応答関数から統計的に最も確からしいモード特性を同定できる非線形最適化法を使用し，モード特性を求める．ユーザによる使い易さをMATLABによりプログラミングされた実験モード解析システムを使用する．本研究では，シロッコファンに適用し，同定されたモード特性と有限要素法による結果を比較・考察する．, Many products are designed by experience and intuition of engineers and are also developed by the repetition of a trial product and an experiment. However, the design conditions which become future still severer are fulfilled, and in order to increase efficiency of development. Raising accuracy etc. from the conventional technique is wanted to produce a new technique. In recent years, modal analysis is beginning to be effectively used for anticipation and elucidation of a vibration phenomenon. Experimental modal analysis with frequency response functions by vibration testing is a series of methods of extracting the dynamic characteristic of the system in the form of the modal parameters. It is widely used as base technology of vibration analysis. Moreover, use of the simulation analysis of the vibration in a design step is becoming familiar by rapid progress of computer and software. The purpose of this study is identification of modal parameters with the nonlinear optimum method as the experimental modal analysis technique. This technique is correctly extended to a multi-point response in differential iteration method. User interfaces are constructed with MATLAB in personal computer. This system is applied for sirocco fan and compared with FEM results.

実験周波数応答関数から統計的に最も確からしいモード特性を同定できる非線形最適化法を使用し、モード特性を求める。ユーザーによる使いやすさをMATRABによりプログラミングされた実験モード解析システムを使用する。本研究では、サイレンサの内板とサイレンサ全体に適用し、内板については同定されたモード特性と有限要素法による結果を比較・考察する。, The purpose of this study is identification of modal parameters of a sympathy silencer with the nonlinear optimum method as the experimental modal analysis technique. This technique is correctly extended to a multi-point response in differential iteration method. User interfaces are constructed with MATRAB in personal computer. This system is applied for the a bar of duct. And the experimental modal parameters are compared with FEM results.

本研究では実際の稼動中に主板とBladeとの結合部に亀裂が入った大型送風機用インペラーの亀裂原因を解明するために有限要素法による振動解析と遠心力による応力解析を行った．解析結果よりインペラーの亀裂の原因は，遠心力により側板が波打つ現象が起こり，主板とBladeとの結合部に集中応力が発生するためだということがわかった．そこで応力低減を狙って擬似最小二乗法による構造最適化を行った．設計変数を要素の板厚，挙動制約条件を最大応力とし繰返し計算を行ったところ，4回の計算で目標値まで応力を低減することができた., In this research, in order to clarify the cause of the impeller for a large-sized fan by which the crack occurred during actual operation at the joint part of the main board and Blade, vibration and stress analysis using the finite element method were performed. The analysis result showed that the cause of a crack of impeller is for concentration stress to occur in the joint part of the main board and Blade owing to the wave phenomenon of the side board by centrifugal force. Then, the structure optimization by pseudo-inverse method was performed for the purpose of stress reduction. When the design variable was made into the board thickness of an element, design constraint was made into the maximum stress and repetition calculation was performed, stress was able to be reduced to the target value by calculation of four calculations.

今まで本研究室で用いている擬似最小二乗法は、Shell要素に適した最適化手法であり、この超小型インペラーはSolid要素のため、最適化しようとすると設計変数の定義が困難となる。そこで今回Solid要素からなるインペラーの最適化ができるように熱変形を利用する形状変更を行い、このモデルの応力低減を試みた。, This micro impeller consists of a Solid element, so it is difficult to be defined a design variable by the optimization technique to which the mathematical pseudo-inverse method used at this laboratory until now was suitable for the Shell element. Then a form change using heat deformation was made, so that optimization of the impeller this time could be performed, and stress reduction of the model was tried.

身の回りにある製品というものは振動現象を利用して商品化されているものがある。ゴルフを気持ちよくするにはゴルフクラブのスイング音、ボールとの衝突音が製品化に問われるところである。そこで今回研究課題として取り上げるのは後者である。実験、シミュレーション、ミズノの算出値の同定をした上で衝突音を設計段階である程度予測し向上へとFORTRANで音響プログラムを作成し実験の音と比較した。, The product in personal appearance has some which are commercialized using the vibration phenomenon. Commercial production is just going to become problem about the swing sound of a golf club, and collision with a ball by that a feeling improves golf. Then, it is the latter which is taken up as a research subject this time. The experiment, the simulation, and the calculation value of Mizuno were identified. Collision sound was predicted to some extent in the design stage on it and to improvement the sound program which was created in FORTRAN compared with the sound of an experiment.

近年、数値解析プログラミングにオブジェクト指向方法を用いる傾向があり、有限要素解析ソフト等に盛んにもちいられている。しかし、その様なソフトは商業ベースの物であり、かつ、大変高価である。そこで、この論文はオブジェクト指向方法を用いた教育現場に役に立つ２次元骨組解析応用ソフトを開発することにした。また、骨組解析の基本概念と２次元骨組解析の解析例を示す。, The difficulties involved in developing and maintaining complicated software systems have prompted engineers to develop newer and sophisticated programming tools. Object-oriented programming (OOP) is one such development and languages supporting it have become popular in recent years. In the field of educational apprecation soft (structure analysis) also, there have been attempts to make use of the facilities offered by object-oriented languages.

実験周波数応答関数から統計的に最も確からしいモード特性を同定できる非線形最適化法を使用し，モード特性を求める．ユーザによる使い易さをMATLABによりプログラミングされた実験モード解析システムを使用する．本研究では，切り込みが入った円筒とRVリアパネルに適用し，同定されたモード特性と有限要素法による結果を比較・考察する．また，実験データの精度向上のために打撃試験装置を作製し，その有効性を検証する．, Ｍany products are designed by experience and intuition of engineers and are also developed by the repetition of a trial product and an experiment. However, the design conditions which become future still severer are fulfilled, and in order to increase efficiency of development. Raising accuracy etc. from the conventional technique is wanted to produce a new technique. In recent years, modal analysis is beginning to be effectively used for anticipation and elucidations of a vibration phenomenon. Experimental modal analysis with frequency response functions by vibration testing, is a series of methods of extracting the dynamic characteristics of the system in the form of the modal parameters. It is widely used as base technology of vibration analysis. Moreover, use of the simulation analysis of the vibration in a design step is becoming familiar by rapid progress of computer and software. The purpose of this study is identification of modal parameters with the nonlinear optimum method as the experimental modal analysis technique. This technique is correctly extended to a multi-point response in differential iteration method. User interfaces are constructed with MATLAB in personal computer. This system is applied for the cylinder containing the slit and RV rear panel. And the experimental modal parameters are compared with FEM results. Moreover, the impact test equipment is produced for the improvement in accuracy of experimental data, and the validity is verified.

本論文は、有限要素法と磁気回路法の接点を見出し、磁気回路法で使われる技術者の経験的要素を有限要素法へ導入して、実用的な電磁機器の設計へ寄与できる現代磁気回路理論を提案するものである。さらに、この現代磁気回路理論による磁束分布にウェーブレット変換を適用した結果、ウェーブレット変換は磁束分布を評価するために有用な方法であることを報告する。, Previously, in order to carry out the three-dimensional magnetic field analysis in a most efficient manner, we proposed the theory of modern magnetic circuits based on finite elements discretization. This makes it possible to implement the three-dimensional magnetic field computation in a quite efficient manner similar to those of the conventional magnetic circuit theory. In the present paper, we try to apply the wavelet transform to a magnetic flux distribution in order to represent it by small computational effort. As a result, it is shown that the wavelet transform yields a fairly good distribution from small computation.

現在、有限要素法はもうすでに確立されたものであると考えられがちであり、また、そのプログラムは完全にブラックボックスとして使われてしまっている。しかし、現在使われているプログラムが実際に最良の解析方法となっているかどうかということに疑問を抱いてみる必要があり、今一度その内容について検討してみるべきではないだろうか。そこで今回は汎用有限要素法ソフトNastranと手計算による理論値およびPost処理における応力の違いを明らかにしたうえで、超小型遠心圧縮機用インペラーの振動と応力の解析を行い検討した。, It tends to be thought that a finite element method is already established now, and the program will be completely used as a black box. However, the program used now needs to have a question for whether it is actually the best analysis method, and we should examine the program once again. Then, after clarifying the difference between the stress value by Nastran and the theoretical value by manual calculation, we performed analysis of vibration and stress of impeller for micro centrifugal compressors.

圧密支配方程式の数値解析では、材料パラメータは圧密進行中において一定として扱われることが多い。しかしながら、圧密は、間隙水の排水を伴いながら間隙の有効径を縮小し、土粒子骨格をより密な構造へ移行させる過程である。したがって圧密過程では、間隙水の流れと土粒子骨格構造の変形を支配するそれぞれの構成モデルは、当然のことながら非線形モデルとして扱わざるをえない。圧密の進行に伴う間隙比、透水係数および体積圧縮係数の変化を調べるために、正規圧密粘土を使った圧密～透水試験を行った。この試験結果に基づき、透水係数を間隙比（体積ひずみ）の関数として表現した間隙水の流れに関する非線形構成モデルを示した。また、土粒子骨格の弾性係数を静水圧有効応力の関数とした非線形構成モデルを示した。さらに、これら２つの構成モデルを組み込んだ三次元圧密プログラムによる２・３の解析例を示し、線形との比較および考察を行った。, In the numerical analysis of the consolidation governing equation , a material parameter treated as constant in process of consolidation progress. However, it is considered that the governing equation should consider non-linear of material. For the purpose of relating the change of the permeability in the progression of the consolidation to the void ratio , the consolidation and permeability tests is carried out to normal consolidated clay. The non-linear constitutive relation between permeability and void raitio and Young’s modulus defined a function of effective hydrostatic stress was applied to three-dimensional consolidation program. Compare the non-linear analysis results with the linear was examined.

本論文は、有限要素法と古典的磁気回路法の接点を見出し、数学的背景が明確な磁気回路法を確立する一方途を議論するものである。具体的には、有限要素法では容易に解析可能な問題である反面、従来の磁気回路法ではモデル化が困難な例題を通して、有限要素法と磁気回路法の接点を見出し、磁気回路法で使われる技術者の経験的要素を有限要素法へ導入して、実用的な電磁機器の設計へ寄与できる現代磁気回路理論を提案する。, As is well known, conventional magnetic circuit theory makes it possible to analyze the three-dimensional magnetic fields, even though its theoretical background is based on the engineering experiences and its accuracy essentially depends on the assumed magnetic circuits. On the other side, because of the widely spreading use of the digital computers, most of the magnetic field analysis is being carried out by finite elements. The finite elements have a firm theoretical background but it is too expensive to implement the three-dimensional analysis. In order to carry out the three-dimensional magnetic field analysis in a most efficient manner, we propose the theory of modern magnetic circuits(TMMC, in short) based on finite elements discretization. This makes it possible to implement the three-dimensional magnetic field computation in a quite efficient manner similar to those of the conventional magnetic circuit theory. In the present paper, we generalize the two-dimensional theory of modern magnetic circuits to the quasi-three-dimensional magnetic circuits. A simple example demonstrates not only the usefulness but also validity of our new methodology.

本論分では、試作した差動コイル型磁気センサーの磁界分布を有限要素法を用いて解析する。。そして、実際に測定した磁界分布と比較し、磁界分布の特徴を考察する。また、有限要素法により求めた磁界分布に時間方向へのウェーブレット変換の多重解像度解析を行い、励磁コイルによる磁界とターゲット金属の渦電流による磁界に分離する。, Time domain electrical signal represents various physical signals, for example, sound, pressure and so on. In any signals, it is classified into two major signal components. One is a meaningful signal reflecting on a physical cause. The other is the noise caused by various physical and artificial conditions, e.g., electromagnetic inductions when converting the physical signals into electrical quantities. Thereby, extraction of a meaningful time domain signal is one of the most important processes in the sensor signal processing.In the present paper, at first, we evaluate the finite elements solution of a magnetic sensor in order to obtain the noise free sensor signal components. Second, we carry out the practical sensor signal measurements. Third, we compare them to estimate the noise signal components. Thus, it is possible to exact only the meaningful sensor signals theoretically. To search for the noise cause, we visualize the magnetic fields of the sensor and check up the electromagnetic disturbances caused by the sensor target. As a result, it is found that the major electromagnetic noise components are caused by the mechanical accuracy of the sensor structure not by the environmental electromagnetic inductions.

数値シミュレーションの結果から、反磁界係数が小さいコア形状では磁性体コアの周波数特性がインダクターの特性に直接反映し、反磁界係数が大きい薄型の場合、磁性体コアの周波数特性の影響が低下し、インダクタンスが減少することを報告する。, In order to design a planar inductor, this paper carries out several axisymmetrical magnetic field simulations fully taking the magnetic hysteretic properties of ferromagnetic core materials as well as open boundary condition into account.Finite element method is applied to evaluating the magnetic fields, reactive and dissipative energies in a planar inductor. Because of the nature of magnetic fields, it is essentially taken into account the open boundary effects to evaluate the exact characteristics of planar inductor. Since the finite elements is one of the methodologies to solving for the partial differential equations, and then it has been difficult to take the open boundary effects into account. However, this paper removes this difficulty by employing the strategic dual image (SDI, in short) method. Another difficulty is caused by the hysteretic magnetization characteris tics of magnetic core materials. Applying the Chua type magnetization model to represent the hysteretic property also removes this difficulty.As a result, it is revealed that the frequency characteristic of core magnetic materials as well as shape dominate major characteristics of the magnetic fields, reactive and dissipative energies in the inductors..

飽和した多孔質弾性体の線形圧密問題に関する支配方程式がBiotによって導かれた．しかしながら，この方程式は，地盤を弾性体として扱うなど実際の圧密特性を十分に表現していない仮定を含んでいる．本研究では，土粒子骨格構造を弾塑性体として扱うものとし，降伏関数として限界状態論に基づくCam-clayﾓﾃﾞﾙを拡張した新たなモデルを示し，具体的に３次元弾塑性－圧密有限要素プログラムに導入した．また，その実用性を評価するために，弾塑性解と線形弾性解の比較を行った．その結果，弾塑性解析から評価される圧密速度は，線形弾性解に比べかなり遅く，かつ線形弾性解による圧密沈下量は過小評価されることを示した．, An equation of the linear consolidation theory for saturated and porous elastic body was derived by Biot. However, the equation includes assumptions that are different from real consolidation phenomenaThe purpose of this study is to develop a 3-D elasto-plastic FEM program for consolidation problem, and evaluate and examine a practicability. The results show a difference between linear elastic analysis and elasto-plastic analysis to disappearance process of excess porewater pressure and settlement of consolidation, etc.

限界状態論をもとにした降伏関数（法政モデル）は，様々な粘性土において適応できるモデルとして開発された．しかしながら，このモデルは，密な土における降伏から破壊状態に至り，限界状態に達するという挙動を表現することはできない．本研究では，この挙動を表現可能にする為に，法政モデルを拡張（修正法政モデル）した．また，修正法政モデルの実用性を評価・検討するために，室内試験結果と両モデルにおける有限要素解析結果の比較を行った．その結果修正法政モデルは法政モデルと比較して，応力状態を比較的より良く表せることが確認された．しかしながら，実際問題の適用性について，モデルの改良，材料パラメータの評価精度の向上等，今後改善すべき多くの課題が残された．, Hosei-model based on the critical state soil mechanics was the yield function which considered only critical state. When some soils are sheared on the undrained state, they reach the critical state after reaching the failure state. In this study, Hosei-model was expanded to express this behavior (modified Hosei-model). And the comparisons between numerical prediction using modified Hosei-model and the undrained triaxial test data were performed in order to evaluate and investigate a practical use of the new model. The finite element analyses about the problem of bearing capacity were carried out. It was ascertained that modified Hosei-model could express the stress path more fairly than Hosei-model. But about the practical use, it was showed that modified Hosei-model had many problem which had to improve.

近年、有機塩素系化合物による地下水と土壌汚染が深刻化している。汚染の進行状況を知るためには、現場での実測が望ましいが、現実ではその方法は地域に与える影響が大きく困難である。本研究では現実に近いモデルを設定し、浸透流および移流拡散解析プログラムを用い帯水層の汚染の進行と浄化について数値解析を行った。また本研究での解析手法と解析プログラムの妥当性を確認するため、飽和地盤中における汚染物質の移流拡散現象とその浄化に関する模型実験を実施した。, In recent years, ground water and the soil pollution by organic chlorine system compound are serious. To know the progress situation of the pollution, the measurement in the scene is desirable, but actually it is difficult. In this study, it set an near model actually, and it did a numerical analysis about the progress and the purge of the pollution of the aquifer using a seepage flow and an advection diffusion program. Also, to confirm the validity of the analysis technique in this study, it implemented a model experiment about the contamination quality advection diffusion phenomenon and the purge of it in the saturated ground.

近年,構造物の形状の複雑化という背景から計算機を用いた数値解析が注目されている.現在,様々な分野で用いられている手法が有限要素法(FEM)である.そんな中で,線形のみならず非線形問題をも視野に入れた設計の必要性が高まっている.しかしながらFEMには要素境界での連続性が要求されるという制限があり,不連続な現象を扱いづらい.そこで本論文では境界積分型解法であるため不連続な現象の扱いが容易である有限体積法（FVM）に着目し,FEMの考えを踏まえつつFVMにより材料非線形問題に関する解析を行う, In this paper, analysis the development of the fracture are considered on the surface rather than the volume element. To establish the natural computational method of the fracture development phenomena, finite volume based surface integration formulation is proposed rather than finite element volume integration formulation. Proposed formulation will be converted to the standard finite element algorithm for the practical implementation.

A novel methodology is proposed to visualize the electromagnetic vector fields. First, in order to apply the field theory of computer graphics proposed in this paper, an electromagnetic field vector is represented as a color image. According to our theory, the high-resolution image can be generated in accordance with like a natural phenomenon. Consequently, it is possible to obtain more precise electromagnetic field from the poor measured data. Secondary, we have applied our method to the practically experimented magnetic fields. As a result, validity of our method has been verified., 本論文では、画像処理の一方法とそれを応用した電磁界ベクトルフィールドの可視化方法を提案する。第１に、本論文で提案する画像処理方法を電磁界分布解析へ応用するために、３次元ベクトルフィールドをカラー画像で表現する。そこで得られる画像を偏微分方程式で記述し、その方程式を解くことであらゆる画素数の画像を生成する。結果として、測定点数の少ないデータからより詳細な電磁界分布データが得られる。第２に、検証実験として、高周波駆動を前提とするフィルム状変圧器を用いたDC/DCコンバータ周辺に分布する磁界を測定し、本手法を適応する。

線形ポテンシャル場を用いた有限体積法による地下水浸透問題の解析法を提案する．有限体積法(FVM)は，非直交格子を用いた有限差分近似として流体力学や移動現象論などの分野において広く用いられている．特に，地盤環境の問題である地下水による汚染拡散のような水以外との連成問題を解く手法として利用されている．これらの方法は，主に，水頭場を一定として取り扱っている．しかし，FVMは非Galarkin重みを有する有限要素法(FEM)の特殊なケースと考えることができるため，水頭場の次数を高めることで，より精度の高い解析が可能となる．本研究では，FEMの四角形要素と同一の水頭場を仮定し，FEMの概念を導入した定式化を試みた．さらに，本手法によって得られる解の特性を検討するため，簡単な数値計算例によりFEM解との比較検討を行った結果を示す．, A numerical method of seepage flow problems by finite volume method using the linear potential field is proposed. Finite volume method (FVM) is widely used as a finite difference approximation using the non-orthogonality grids in fields such as fluid dynamics and transport phenomenon. Especially, it is used as the technique which solves the coupled problem like the pollution diffusion by the groundwater which is a problem of the ground environment. In these methods, there are many cases in which the water head field is handled as being constant. However, FVM can be considered to be a particular case of finite elements with a non-Galarkin weighting. Therefore, the analysis accuracy is improved by raising the degree of the water head field. In this paper, water head field which is identical with the quadrilateral element of FEM is assumed, and the formulation which introduced the concept of FEM is developed. In addition, the result of the comparison examination with the FEM solution according to the simple model for examining characteristics of the solution by this method is shown.

高周波駆動を前提とした磁気素子は、数ターンのコイルで構成されているため、必然的に漏れ磁束を伴う。そこで、磁気素子の漏れ磁束を考慮した最適設計を行うべく、その第一段階として、周辺領域を含めたフェライトトロイダルコアの電磁界分布解析を行う。この開領域軸対称三次元問題解析に対し、入力項に磁流密度を導入し、電気影像法を拡張した双対影像法により有限要素解を導く。, This paper proposes a finite element method using the magnetic current density as an input vector for solving the electromagnetic field problem having an open boundary. This method is based on the strategic dual image forcing an open boundary to close for the finite element solution of open boundary problem.In this paper, we analyzed the electromagnetic field distributions of inside and vicinity of a ferrite toroidal core taking into account the magnetization characteristics and estimated the hysteresis loops as well as skin effects.

有限体積法（FVM）では，辺を基にしたデータ構造を扱うことにより，制御体積の境界辺に沿った境界積分を用いて要素行列やベクトルを計算している．このため節点での変位の連続性が要求される有限要素法よりも比較的容易にき裂の進展などの不連続な現象が導入できる．そこで本論文では，弾塑性問題における有限要素の概念を導入した有限体積法の定式化を増分形式で行い，数値例として弾性解に関する精度を検討する．そして最後に進行型破壊現象についての解析を行う．, Almost of criteria for the initiation and the development of the fracture are considered on the surface rather than the volume element. To establish the natural computational method of the fracture development phenomena, finite volume based surface integration formulation is proposed rather than finite element volume integration formulation. Proposed formulation will he converted to the standard finite element algorithm for the practical implementation.

構造解析において，板やシェル状のような構造物はその形状特性を考慮すると三次元解析よりもむしろ二次元解析によって解かれる．本論文では，対象領域を板やシェル状として，移流項を含む移流拡散解析に対する効率の良い定式化のシュミレーションを提案する．, In the structural analysis, plate and shell like structures will be solved by the two dimensional analysis rather than the three dimensional full analysis by considering the thickness mechanical properties. In this paper we will propose simulate effective general formulation for the heat transfer problems with convection term.

本論文では数値解析結果の物理的解釈を的確に行うために、コンピュータグラフィックスを用いた可視化について考察を行う。有限要素法によるスカラー、ベクトルおよび二階のテンソルに対する全体的な方向場を可視化するための手法に対し考察し、3次元での実現を目指す。, Visualization methods that are based on modern computer graphics techniques play an essential role in physical interpretation of the computational results from finite element analysis.A new algorithm is presented for effective color presentation of flow lines for scalar, vector and second order tensor variables predicted by computational analysis. This method is based on contour line representation of the streamline potential function of a given vector field.