Researchers Database

MARUYAMA, Taizo

    Graduate School of Science and Engineering Civil and Environmental Engineering Senior Assistant Professor
Last Updated :2020/08/07

Researcher Information

URL

J-Global ID

Research Interests

  • Nondestructive evaluation   Elastic wave   Computational mechanics   Applied mechanics   

Research Areas

  • Social infrastructure (civil Engineering, architecture, disaster prevention) / Structural and seismic engineering

Published Papers

  • Terumi Touhei, Taizo Maruyama
    International Journal of Solids and Structures 169 187 - 204 0020-7683 2019/09 [True][False]
     Scientific journal 
    © 2019 Elsevier Ltd A method for reconstructing the locations of point-like scatterers in an elastic half-space is developed in this article. Point-like scatterers are characterized by fluctuations of the Lamé parameters and the mass densities from the background structure of the wavefield. A representation of the wavefield is realized with the monopole and dipole Green's functions. The main contribution of the present work is to clarify the far-field properties of the Green's functions for both the monopole and dipole sources, which yields the pseudo-projection approach to the wave problem. Indicator functions that reconstruct the locations of point-like scatterers are defined by the far-field operator derived from the pseudo-projections and the near-field observation. Numerical computations were carried out to verify the accuracy of the pseudo-projection method. The sensitivities of the accuracy of the reconstruction results for the proposed method to random noise, the grid resolution at the free surface, and the analyzed frequency were also examined.
  • Taizo Maruyama, Terumi Touhei
    Journal of the Acoustical Society of America 143 (6) 3545 - 3556 0001-4966 2018/06 [True][False]
     Scientific journal 
    © 2018 Acoustical Society of America. The present article describes the steady-state numerical modeling of anti-plane shear wave scattering by a crack with frictional boundary conditions. The system is composed of an unbounded elastic solid that includes a closed crack under static compressive stress. A time-harmonic anti-plane shear wave is incident, and dynamic friction between the crack faces is induced as a nonlinear phenomenon. The anti-plane wave scattering can be described in a retarded potential integral equation by taking the nonlinearity into account. The present article introduces the steady-state expression as an asymptotic vibration of crack faces after a sufficient elapsed time. In order to solve the equations describing nonlinear steady-state vibration, a harmonic balance method is integrated into a boundary element method. Fourier coefficients of crack opening displacement distributed on the crack face are treated as unknown variables. The system of nonlinear equations is solved by means of a numerical continuation method. The present numerical results show almost complete agreement with those obtained by the conventional time-domain analysis after a sufficient elapsed time. Furthermore, the robustness and effectiveness of the proposed method are demonstrated numerically.
  • On stability of steady-state solutions by harmonic balance-boundary element method for scattering problems by a crack with contact acoustic nonlinearity
    Taizo Maruyama, Terumi Touhei
    土木学会論文集A2(応用力学) 74 (2) I_179 - I_189 2018 [True][False]
     Scientific journal
  • Taizo Maruyama, Takahiro Saitoh, Sohichi Hirose
    International Journal of Solids and Structures 126-127 74 - 89 0020-7683 2017/11 [True][False]
     Scientific journal 
    © 2017 Elsevier Ltd Recently, the ultrasonic testing (UT) based on the contact acoustic nonlinearity (CAN) has attracted notice as a new technique for detection of closed cracks which cannot be detected by using the linear UT (LUT). In the nonlinear UT (NLUT), detection and size measurement of flaws are conducted via the frequency spectrum analysis of nonlinear ultrasonic waves which consist of higher- and sub-harmonic waves. Although the mechanism of higher-harmonic generation due to CAN has been understood mostly from theoretical and experimental points of view, that of sub-harmonic generation has not been revealed yet. In addition, there are few numerical and theoretical studies on the phenomenon of sub-harmonic generation due to the CAN. In this paper, the boundary integral equation for two-dimensional (2-D) elastic wave scattering by cracks is formulated and numerically solved to investigate the behavior of the sub-harmonic waves. The clapping motion and dynamic friction on crack faces are modeled by considering contact boundary conditions, and their interaction with the characteristic of frequency response in the corresponding linear system is investigated. In this study, time-domain numerical simulations are implemented for both an interior crack in an unbounded elastic solid and a surface breaking crack in an elastic half-space. Some frequency response analyses for a linear system corresponding to the time-domain nonlinear simulations are also performed by using the frequency-domain boundary element method. From obtained numerical results, the causes of sub-harmonic generation are discussed.
  • Harmonic balance-boundary element method for scattering problem with contact acoustic nonlinearity on crack face
    Taizo Maruyama, Terumi Touhei
    計算数理工学論文集 17 65 - 70 2017 [True][False]
     Scientific journal
  • T. Maruyama, T. Saitoh, T. Q. Bui, S. Hirose
    Computer Methods in Applied Mechanics and Engineering 303 231 - 259 0045-7825 2016/05 [True][False]
     Scientific journal 
    © 2016 Elsevier B.V. Existing boundary element methods (BEMs) have been proven to be efficient numerical techniques particularly in modeling wave propagation problems but still remain limitations in solving large-scale problems. The main disadvantages may be caused by several problems, including high cost and large amount of computer memory for the computation. A time-domain BEM in which a collocation method is used for the time discretization also shows numerical instability for small CFL (Courant-Friedrichs-Lewy) number. In this work, we propose a new three-dimensional (3-D) approach for solving transient elastic wave propagation problems of large-scale spherical and spheroidal cavities by the convolution quadrature BEM accelerated by fast multipole method (FMM) using an implicit Runge-Kutta scheme (in abbreviation, we name it as IRK-based CQ-FMBEM). Two special techniques pertaining to the FMM including the scaling of modified spherical Bessel functions and the truncation method are used to enhance the efficiency and stability of our proposed method. This approach is found to be particularly suitable for 3-D large-scale problems as its high accuracy, stability of time-marching process, and computational efficiency. These properties are subsequently illustrated through numerical examples dealing with large-scale wave problems of 3-D single spherical and spheroidal cavities and multiple equally and irregularly spherical cavities. The accuracy of the present formulation is verified by comparing the obtained results with available reference solutions in the literature. Some numerical aspects of time increments, sizes and topological shapes of cavities, and their influences on the deformations and the waveforms are investigated. Also, detailed investigation of the computational efficiency of our proposed method, such as CPU time, required memory, etc. is presented. All the implementation tasks are carried out using the Tokyo Tech. supercomputer which is called TSUBAME 2.5 [42].
  • 3-D numerical simulation of sub-harmonic generation phenomenon due to contact acoustic nonlinearity on crack faces
    Taizo Maruyama, Takahiro Saitoh, Sohichi Hirose
    土木学会論文集A2(応用力学) 72 (2) I_217 - I_226 2016 [True][False]
     Scientific journal
  • 丸山 泰蔵, 斎藤 隆泰, 廣瀬 壮一
    計算数理工学論文集 日本計算数理工学会 15 67 - 72 1348-5245 2015/12 [True][False]
     Scientific journal
  • 2-D Simulation of Sub-harmonic Generation Due to Cracks with Contact-boundary Conditions
    Taizo Maruyama, Takahiro Saitoh, Sohichi Hirose
    土木学会論文集A2(応用力学) 71 (2) I_299 - I_310 2015 [True][False]
     Scientific journal
  • 斎藤 隆泰, 金井 翔平, 丸山 泰蔵
    計算数理工学論文集 日本計算数理工学会 14 31 - 36 1348-5245 2014/12 [True][False]
     Scientific journal
  • 丸山 泰蔵, 斎藤 隆泰, 廣瀬 壮一
    計算数理工学論文集 日本計算数理工学会 14 55 - 60 1348-5245 2014/12 [True][False]
     Scientific journal
  • MARUYAMA Taizo, SAITOH Takahiro, HIROSE Sohichi
    Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)) 公益社団法人 土木学会 70 (2) I_235 - I_246 2014 [True][False]
     
    The nonlinear ultrasonic testing is expected to be an effective technique for detection of closed cracks which cannot be detected by the linear ultrasonic testing. However, although the nonlinear ultrasonic waves such as higher- and sub-harmonics are considered as generated by the interaction of the crack faces such as clapping motion or friction, the mechanism of generation has not been understood clearly from theoretical viewpoints yet. Therefore, the boundary integral equation for an interface crack with nonlinear boundary conditions in 3-D is formulated, and numerically solved using the convolution quadrature time-domain boundary element method (CQ-BEM) in order to investigate the behavior of nonlinear ultrasonic generation.
  • MARUYAMA Taizo, SAITOH Takahiro, HIROSE Sohichi
    Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)) 公益社団法人 土木学会 69 (2) I_175 - I_185 2013 [True][False]
     
    This paper presents an implicit Runge-Kutta (IRK) based convolution quadrature time-domain fast multipole boundary element method (CQ-FMBEM). Application of a convolution quadrature method (CQM) to a time-domain boundary element method (BEM), which is called CQ-BEM, can improve numerical stability of time-stepping procedure. In recent researches, the IRK based CQ-BEM showed better performance than the conventional linear multistep based one regarding accuracy. However, the IRK based CQ-BEM requires more computational time and memory. Therefore, in this paper, the fast multipole method (FMM) is applied to the IRK based CQ-BEM for 3-D scalar wave propagation problems. The formulation of the IRK based CQ-BEM and the application of the FMM are described. The accuracy and computational efficiency of the proposal method are compared with the linear multistep based CQ-FMBEM by solving some numerical examples.
  • 丸山 泰蔵, 斎藤 隆泰, 廣瀬 壮一
    計算数理工学論文集 日本計算数理工学会 12 91 - 96 1348-5245 2012/12 [True][False]
     Scientific journal
  • 斎藤 隆泰, 丸山 泰蔵, 廣瀬 壮一
    Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)) 公益社団法人 土木学会 67 (2) I_145 - I_152 2011 [True][False]
     
    This paper presents a convolution quadrature time-domain boundary element method for fluid-elastic half space. Application of convolution quadrature method (CQM) to time-domain boundary element method (BEM), which is called CQ-BEM, can help improve numerical stability of time-stepping procedure. However, the conventional CQ-BEM for fluid-elastic half space has two disadvantages. First, it requires much memory to evaluate retarded potentials of time-stepping procedures. Second, it is difficult to couple both boundary integral equations for fluid and elastic half space with time-domain boundary conditions on fluid-elastic interface directly. The formulation presented herewith improves these disadvantages by transforming boundary values in time-domain into Fourier-domain. As numerical examples, air-coupled ultrasonic simulation is shown to validate the presented method.

MISC

  • Taizo Maruyama, Terumi Touhei  Proceedings of Meetings on Acoustics  29-  (1)  2016/11  [True][False]
     
    © 2017 Acoustical Society of America. In nonlinear ultrasonic testing (NLUT) based on contact acoustic nonlinearity (CAN), higher- and subharmonic waves are measured and analyzed for detection of cracks. Theoretical explanation of the harmonic generation is desirable for accurate NLUT. In particular, the steady-state motion of crack faces is supposed to significantly affect behavior of higher- and sub-harmonic wave generation. However, the detail of wave scattering by cracks with CAN has not been clarified yet. Therefore, in order to investigate the detail of steady-state vibration accompanied with contact of crack faces, the authors coupled the boundary element method (BEM) and harmonic balance method. In the proposed method, a concept of the steady-state and nonlinear vibration of crack faces is introduced as asymptotic behavior of vibration that can be recognized after sufficiently elapsed time. The scattering model is for the antiplane shear wave field that causes the crack face friction. Several numerical calculations were performed to examine and verify the accuracy of the proposed formulation. The present results showed almost complete agreement with those obtained by the conventional time-domain BEM. It was also found that the nonlinear effects for the present model were mainly due to the third-order higher-harmonic waves.
  • 丸山 泰蔵, 廣瀬 壮一  非破壊検査  64-  (12)  586  -592  2015/12  [False][False]
  • 丸山 泰蔵, 斎藤 隆泰, 廣瀬 壮一  計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science  20-  6p  2015/06  [False][False]
  • ICHIKAWA Ryo, SAITOH Takahiro, MARUYAMA Taizo, HIROSE Sohichi  The Proceedings of The Computational Mechanics Conference  2015-  (0)  _216  -1_-_216-2_  2015  [False][False]
  • 廣瀬 壮一, 丸山 泰蔵  非破壊検査  63-  (3)  108  -112  2014/03  [False][False]
  • HIROSE Sohichi, TACHIBANA Hajime, NAKAMOTO Keisuke, SHIMADA Yoshinori, KOTYAEV Oleg, YAMAGUCHI Yuuya, MARUYAMA Taizo  The Proceedings of Mechanical Engineering Congress, Japan  2014-  (0)  _J0420204  --_J0420204-  2014  [False][False]
     
    In Japan, concrete slabs of highway bridges, especially ones constructed before 1970, have suffered fatigue damage due to repeated traffic loads. "Steel plate bonding method" has been widely used for over 30 years to strengthen damaged concrete slabs. In recent years, however, the repaired structures have also been damaged due to the debonding of adhesive resin between a steel plate and concrete. In this study, a laser based ultrasonic method is developed for remote inspection of bonded steel plates. Some results are obtained in a laboratory measurement of specimens, and are discussed in comparison with impact hammer method and numerical results. It is shown that the laser based method has a promising possibility of effective nondestructive evaluation for steel plate bonding of highway bridges.
  • Sohichi Hirose, Seitaro Nishimoto, Taizo Maruyama, Yasuaki Nagata  AIP Conference Proceedings  1581 33-  36  -41  2014  [True][False]
     
    A time domain synthetic aperture focusing technique (SAFT) for flaw imaging of immersed structures with curved surfaces is improved in conjunction with approximate wave solutions, which were obtained in an explicit form by Schmerr (1998). In the improved SAFT, the approximate solutions are used to normalize A-scan waveforms and then the normalized waveforms are superimposed to obtain images with high contrast for a flaw in a structure in curved surfaces. As examples, the proposed SAFT is applied to experimental data for a side drilled hole (SDH) in an immersed round bar. © 2014 AIP Publishing LLC.
  • Taizo Maruyama, Takahiro Saitoh, Sohichi Hirose  AIP Conference Proceedings  1581 33-  550  -555  2014  [True][False]
     
    Air-coupled ultrasound testing is known as one of attractive non-contact ultrasonic NDE methods. However, the sensitivity of the air-coupled method greatly depends on the positioning of transducers, because the difference of acoustic impedance between air and solid is very large. In order to use this method for quantitative detection and evaluation of material flaws, it is necessary to simulate ultrasonic wave propagation and scattering in a solid. For a coupling problem between two media, in which ultrasonic waves travel at greatly different velocities, it is difficult to obtain stable solutions by means of a conventional time-domain boundary element method (BEM). A convolution quadrature time-domain fast multipole BEM (CQ-FMBEM) has been developed for the simulation of ultrasonic wave propagation and scattering in a solid. In the CQ-FMBEM, a convolution quadrature method (CQM) is introduced to make BEM solutions stable by evaluating a convolution integral in a very accurate numerical manner, while a fast multipole method (FMM) is used to accelerate the computations effectively for large scale problems. In this paper, 2-D and 3-D scattering problems of ultrasonic waves due to defects near an interface between air and solid are solved in order to simulate ultrasound scattering phenomena. © 2014 AIP Publishing LLC.
  • Maruyama Taizo, Saitoh Takahiro, Hirose Sohichi  NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan  62-  (0)  106  -106  2013  [False][False]
     
    This paper presents a 3-D numerical simulation of air-coupled ultrasonic testing. Air-coupled ultrasonic testing is known as one of non-contact ultrasonic NDE methods. However, the air-coupled ultrasonic simulation is very complicated, because the difference of acoustic impedance between air and solid is very large. In recent years, various 2-D numerical simulations have been done in order to qualify the air-coupled ultrasonic testing. However, there have not been so many 3-D simulations for air-coupled ultrasonic testing. In this research, an improved convolution quadrature 3-D BEM is developed for air-coupled ultrasonic simulation. Some numerical results are shown to validate our proposed method.
  • Maruyama Taizo, Saitoh Takahiro, Hirose Sohichi  NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan  62-  (0)  172  -172  2013  [False][False]
     
    This paper presents a convolution quadrature fast multipole boundary element method for 3-D elastodynamics. The formulation is based on the implicit Runge-Kutta method (IRK). In general, a convolution quadrature boundary element method (CQBEM) is known as effective and stable for time-domain wave propagation problems. In particular, IRK based CQBEM can produce higher accuracy than conventional linear multistep based CQBEM. However, IRK based CQBEM requires much memory and computational time. Therefore, in this research, fast multipole method (FMM) is applied to IRK based CQBEM for acceleration. The formulation of IRK based CQBEM and its acceleration by FMM for 3-D elastodynamics are presented. In addition, their accuracies are checked by solving some fundamental wave propagation problems.
  • MARUYAMA Taizo, SAITOH Takahiro, HIROSE Sohichi  非破壊検査 : journal of N.D.I  61-  (3)  111  -112  2012/03  [False][False]
  • MARUYAMA Taizo, SAITOH Takahiro, HIROSE Sohichi  The Proceedings of the Materials and Mechanics Conference  2012-  (0)  _OS0715  -1_-_OS0715-3_  2012  [False][False]
     
    This paper presents a 3D numerical simulation for air-coupled ultrasonic testing. Air-coupled ultrasonic testing has some advantages because this method is one of non-contact ultrasonic NDE methods. However, the positioning of air-coupled transducers is very sensitive, because the difference of acoustic impedance between air and solid is very large. In order to use this method for evaluation of various materials, it needs to simulate wave propagation in a solid medium. A BEM (boundary element method) is an effective method for wave propagation problems. Therefore, the BEM formulation using the CQM (convolution quadrature method) is developed for air-coupled ultrasonic testing and the numerical results for 3D wave simulation are shown.

Awards & Honors

  • 2019/06 JSCE Applied Mechanics Committee Applied Mechanics Best Paper Award
     On stability of steady-state solutions by harmonic balance-boundary element method for scattering problems by a crack with contact acoustic nonlinearity 
    受賞者: Taizo Maruyama;Terumi Touhei
  • 2018/09 JSCE Applied Mechanics Committee Presentation Award
     On stability of steady-state solutions by harmonic balance-boundary element method for scattering problems by a crack with contact acoustic nonlinearity 
    受賞者: Taizo Maruyama
  • 2017/07 東京工業大学土木工学科同窓会「丘友」 Kikkawa Yamagichi Award
     Fast time-domain boundary element method and its application to nonlinear ultrasonic simulation 
    受賞者: Taizo Maruyama
  • 2016/05 JSCE Applied Mechanics Committee Applied Mechanics Encouragement Award
     2-D simulation of sub-harmonic generation due to cracks with contact-boundary conditions 
    受賞者: Taizo Maruyama
  • 2015/01 JASCOME Presentation Award
     Implicit Runge-Kutta based CQ-FMBEM for coupled acoustic-elastic wave problems 
    受賞者: Taizo Maruyama
  • 2013/11 JSCE Presentation Award
     
    受賞者: Taizo Maruyama
  • 2013/03 第62回理論応用力学講演会運営委員 Presentation Award
     
    受賞者: Taizo Maruyama

Research Grants & Projects

  • Advanced steady-state scattering analysis for nonlinear ultrasonic testing based on contact of crack faces
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists
    Date (from‐to) : 2019/04 -2022/03 
    Author : 丸山 泰蔵
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity start-up
    Date (from‐to) : 2016/08 -2018/03 
    Author : Maruyama Taizo
     
    This study dealt with nonlinear ultrasonic testing, which is one of the nondestructive techniques for structures and machines. A novel numerical method was developed to investigate the received wave with 1/2 frequency component of the incident wave in the nonlinear ultrasonic testing. In the numerical simulation, complex resonance was confirmed under certain conditions. This phenomenon is called the subharmonic resonance and was caused by the interaction between fluctuation of resonance characteristic and contact of crack faces. It was indicated that the the scattered wave with 1/2 frequency component is generated in the nonlinear ultrasonic testing as a result of the subharmonic resonance.
  • 大規模波動解析手法の開発及びコンクリート材料に対する非破壊検査への応用
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows
    Date (from‐to) : 2014/04 -2016/03 
    Author : 丸山 泰蔵
     
    平成27年度は,閉口き裂に対する検出手法である非線形超音波法に対する基礎的なアプローチとして,数値シミュレーションによる分調波発生現象の再現,及びその原因の考察を行う予定であった.また,境界要素法・有限要素法結合解法の開発を行い,非線形超音波法の非均質材料へのアプローチを見通しの良いものにする予定であった. 分調波シミュレーションに関しては,平成26年度中に2次元時間領域境界要素法を用いた数値シミュレーションによって材料内部のき裂に対する分調波発生現象の再現に成功したため,平成27年度はその数値シミュレーション手法を材料表面に存在するき裂に対して拡張すること,及び3次元数値シミュレーションの実行を予定していた.成果としては,先行研究の計測実験において分調波発生現象が報告されている材料表面に存在するき裂に対して数値シミュレーション手法を拡張した.その後,数値シミュレーションを実行し,表面き裂による分調波発生現象の再現に成功した.また,その数値シミュレーションから,自由表面による弾性波の反射とき裂面の接触との相互作用によって,分調波発生現象が起こっていることを示唆する結果が得られた.さらに,平成26年度に行った3次元時間領域境界要素法の高速・効率化の成果を元に,非線形超音波法の数値シミュレーション手法を3次元へと拡張し,材料内部のき裂に対して解析を行った.その結果,有限の奥行き長さを有する2次元の場合と似た形状のき裂モデルに対して,分調波の発生が確認できた.また,奥行き長さが分調波発生現象に与える影響を調べた. 非均質材料へのアプローチである境界要素法・有限要素法結合解法の開発に関しては,2次元波動問題に対してGalerkin法を用いた定式化を行い,数値シミュレーションを実行することによって,その妥当性を検証した.


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