-
Article type: Cover
Pages
Cover1-
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Appendix
Pages
App1-
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Appendix
Pages
App2-
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Appendix
Pages
App3-
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Index
Pages
Toc1-
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Dai OKUMURA, Yoichi HIGASHI, Nobutada OHNO
Article type: Article
Session ID: 515
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, we explore the role of grain boundaries in the size effect of polycrystal plasticity. For this purpose, we develop a homogenization theory and its finite element discretization based on the nonlocal single-crystal plasticity theory of Gurtin, which includes slip gradients and additional slip boundary conditions. For finite element polycrystal plasticity analysis, the additional slip boundary conditions are applied on grain boundaries. Two typical slip boundary conditions called micro-free and micro-clamped conditions are considered.
View full abstract
-
Takahiro SHIKAMA, Mitsutoshi KURODA
Article type: Article
Session ID: 516
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In the pure bending, there exists inherently a gradient of plastic strain. Therefore, the pure bending problem is appropriate for investigating the length scale of materials. However, few studies for pure bending at large strain have been done so far. In this study, we perform finite element simulations of pure bending with consideration of length scale and strain localization, by introducing the effect of geometrically necessary dislocations, which has an association with a gradient of plastic strain, into the crystal plasticity model.
View full abstract
-
Shigenobu OKAZAWA, Mitsutoshi KURODA, Hirohisa NOGUCHI
Article type: Article
Session ID: 517
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Although we can simulate diffuse necking, shear band cannot be reached with conventional plastic flow rules in a finite element method. In this study, shear band of ductile metal is simulated by crystal plasticity theory. In addition, and grain number effect on gauss points of shear band is investigated.
View full abstract
-
Yuichi TADANO, Hirohisa NOGUCHI, Mitsutoshi KURODA
Article type: Article
Session ID: 518
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A three-dimensional finite element method for polycrystalline plasticity problems based on the homogenization method has been developed. The homogenization method is one of the useful procedures to combine behaviors in a macro-scale and a micro-scale with periodical structure satisfying physical and mathematical compatibility between those scales. Polycrystalline metals are assumed to have periodical microstructure, therefore, a three-dimensional polycrystalline model is introduced into the homogenization method. In the present method, each material point in the element is considered to be a polycrystalline aggregate of a number of FCC grains where the Taylor theory of crystal plasticity is assumed. It is shown that the proposed method can evaluate macroscopic material properties only with microscopic material information.
View full abstract
-
Isoharu NISHIGUCHI, Aki YAMAMOTO, Masataka SASAKI
Article type: Article
Session ID: 519
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Three dimensional finite element analyses of a piano string are performed in which a large deformation theory is adopted. In a real piano string, a nonlinear hammer contacts with a string for finite time duration depending on the hammer velocity and the interaction force varies due to multiple reflections between striking point and agraffe, In order to simulate this effect by FEM, a point mass with a spring and a dashpot was employed with a gap element. It was shown that the model is able to reproduce the waveforms well including the details of the attack transients.
View full abstract
-
Xian CHEN, Toshiaki HISADA
Article type: Article
Session ID: 520
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A finite element contact analysis algorithm has to pass the so-called patch test. In this work, a new algorithm based on one-pass approach is proposed. In this algorithm, the virtual work due to contact force is evaluated by integrating it on the contact surface. Furthermore, the nodal contact pressure in the master contact surface is transmitted from that in the slave contact surface by projecting the master node onto the slave element. In this way, the proposed algorithm is enabled to evaluate correctly the equivalent nodal force due to contact yielding the success in the patch test. The effectiveness of the new algorithm is verified by a couple of numerical examples.
View full abstract
-
Satoko HIRABAYASHI, Toshiaki HISADA, Masashi INAGAKI
Article type: Article
Session ID: 521
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Although feedback mechanisms from mechanical response to electric activity have been suggested to be significant in cardiac muscles, its details remain unknown. This Mechano-Electric Feedback (MEF) was investigated using dynamic FEA. Cardiac muscle is modeled as incompressible hyperelastic material, which is generally analyzed by implicit methods. To reflect cardiac deformations in fine time intervals and couple mechanical and electrical activities, a new explicit method was constructed by applying decoupled FEM, which is generally used in fluid analysis. The proposed method successfully reproduced MEF and indicated that MEF can change the movements of spiral reentry.
View full abstract
-
Masato TANAKA, Hirohisa NOGUCHI
Article type: Article
Session ID: 522
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The objective of this study is to develop a finite strain shell element whose material is restricted to hyperelasticity. This shell element is based on MITC shell element which was developed by KJ Bathe and EN Dvorkin in 1984 to perform locking-free behaviour using assumed transverse shear strains. In addition to this MITC formulation, we treat thickness change as another assumed variable. In our formulation, thickness change is assumed to be uniform in the element, and evaluated at the middle surface via incompressibility. Unknown pressure, which occurs in incompressible materials, is eliminated at the element level using plane stress condition. The advantage of this technique is that a well-conditioned stiffness matrix can be obtained. Numerical assessment was conducted in this study to illustrate the performance of the present shell element through some examples.
View full abstract
-
Kohsuke TSUCHIYA, Hirohisa NOGUCHI
Article type: Article
Session ID: 523
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The objective of the present study is to investigate an accuracy of the mixed interpolation of tensorial components triangular shell element proposed by Lee and Bathe in 2004 in geometrically nonlinear problems. A large deformation analysis of a pinched cylinder subjected to a concentrated load is conducted and the performance of MITC3 element comparing with the one by MITC4 element is discussed.
View full abstract
-
Toshio NAGASHIMA
Article type: Article
Session ID: 525
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The X-FEM in conjunction with the level set method can be used to simplify the modeling of continua containing several cracks and hence perform effective stress analyses related to fracture mechanics. This paper describes the two-dimensional stress analysis of structures containing cracks. Stress intensity factors having mixed modes coupled with mode-I and mode-II are evaluated by M_1-integral method. This method is examined in numerical examples of elastic analyses. The numerical results show that X-FEM is an effective method for performing stress analyses and evaluating stress intensity factors.
View full abstract
-
Seiya HAGIHARA, Tatsuya YASUKOCHI, Mitsuyoshi TSUNORI, Toru IKEDA, Nor ...
Article type: Article
Session ID: 526
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In the present paper, we estimate error of numerical solutions of the element free Galerkin method (EFGM) for adaptive analyses to evaluate accuracy of the EFGM. We apply a method of smoothing the distribution of nodes to the relocation of all nodes in the domain of an analysis model. The nodal relocation method in which nodes are automatically relocated using physical interbubble force called bubble meshing for the FEM is applied to this adaptive analysis after nodes are increased.
View full abstract
-
Hiroshi AKIBA, Tomonobu Ohyama, Junko Ikeda
Article type: Article
Session ID: 527
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper introduces IBM Blue Gene, which established 1st rate at 24th TOP500 held in Nov 2004, and shows its performance of the large scale structural analysis.
View full abstract
-
Kazuaki IGUCHI, Masaki KITAGOH, Ichiro HAGIWARA
Article type: Article
Session ID: 528
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Reverse engineering is the solution of engineering to gain digital data from existing objects, and which applied CAD, CAM, CAE, and CAT. And surface reconstruction is the technique for making surfaces from existing objects, and is integral to reverse engineering. When we reconstruct surface, scanned points are gained from existing objects with SD-coordinate measuring machines, then surface is reconstructed from scanned points. But scanned points sometimes have problems. Surface reconstruction from incomplete points, such as points including noise, is hard. So, we suggest a method of surface reconstruction using implicit function based on Multi-level Partition of Unity Implicits, which is robust to incomplete points.
View full abstract
-
Junichi SHINODA, Wenjie CHENG, Ichiro HAGIWARA
Article type: Article
Session ID: 529
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently, the techniques in the reverse engineering have become more and more important. In fact the reverse engineering is exploited in many fields, for example, generation of CAD data from the model without CAD data, comparison of a trial product with CAD data in mechanical industry, retention of ruins and statues of Buddha as digital archives in archaeology, and creation of order-made dresses in dress industry. In this article, the techniques of the reconstruction from the point clouds, that is the techniques to generate triangular meshes on the surfaces of the target models, is presented. It can also eliminate some kind of noise which exerts the serious influence in mesh generation. In addition some examples to which the proposed method is applied are shown.
View full abstract
-
Jiping Li, Junichi Shinoda, Ichiro Hagiwara
Article type: Article
Session ID: 530
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Avoiding the pitfalls rampant in exchanging CAD data is a must for efficient and timely product development. Conversion of geometric models may require subsequent repair operations within the receiving system. In the present contribution, a framework is presented for a prototype system TIT CADE which encompasses functionalities for CAD data exchange, repair and more. The system developed has been used for processing solids and surface models provided by industrial companies in several high-end CAD data formats. The purpose has been to improve the integrity of CAD data for subsequent engineering tasks such as the generation of STL data.
View full abstract
-
Wei Li, Zhuoqi Wu, Ichiro Hagiwara
Article type: Article
Session ID: 531
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A method of constructing piecewise G^1 continuous spline surface using boundary C-curves is presented. C-curves are developed by the basis {sin t, cos t, t, 1}, and it overcomes some shortcomings of the non-uniform rational B-splines (NURBS) model. How to develop C-curve into surface becomes a very important problem. Using the convex combination method proposed by Nielson, a piecewise G^1 spline triangular surface is constructed by boundary C-curves.
View full abstract
-
Hiroshi Yamaguchi, Hiroo Yanagawa, Yasuhiko Yoshida
Article type: Article
Session ID: 532
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
K. Murase, F. Morita, H. Yamada
Article type: Article
Session ID: 533
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, a three-dimensional CAD system for free-formed modeling was developed. Operation postures were recognized using digital motion-caputuring system and were reflected the modeling manupulation under the virtual environments. FE modeling for a couple of femural and tibial bone was tried for the application of biomechanical simulation. Some human interfaces and the graphical routines were utilized effectively to emulate the medical operations and to enhance intuitive ones. The alignement of the femur, tibial, and artifial protheses of FE model were possible easily compared with the traditional CAD/CAE systems.
View full abstract
-
Osamu OKUDA
Article type: Article
Session ID: 534
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this research, we describe a dual threshold incomplete Cholesky decomposition method (ILUT(tol,p)) to compute the simultaneous equation of the composite materials with fiber-reinforcements. The fibers are longitudinally surrounded by matrix, and distributed in a cube arrangement. This multi-phase polymer is modeled using the quadrilateral finite element discretization. The effects of the computation based on ICCG solver with a threshold preconditioner and the comparison with other CG methods such as SCG, ICCG(0) are discussed.
View full abstract
-
Makoto TANABE, Masahiko MURATA, Tosiyuki Yoshino, Hidehito MATSUYAMA
Article type: Article
Session ID: 535
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A mesh generation by a hybrid advancing front method with templates used is presented for shell and solid structures. Hexahedral elements partially combined with tetrahedron and pentahedron elements are generated in each layer using templates selected from adjacent information between surface patches. The computer program GMESH3D has been developed. Some examples are demonstrated.
View full abstract
-
Masayuki HARIYA, Yoshimitsu HIRO
Article type: Article
Session ID: 536
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We developed technique for automatically generating a hexahedral mesh of a complex solid model. This technique can automatically convert a solid model to a feature shape model that consists of the feature lines necessary for generating hexahedral mesh. We have thus automated the interactive operations (such as model editing) that are carried out as a pretreatment for hexahedral mesh generation, and significantly shortened the time taken for these interactive operations. Furthermore, in this research, the feature model generation process was improved to generate meshes for multi-volume models. As a result, we confirmed that the process could be used to generate a hexahedral mesh with a consecutive pattern on the common faces between parts.
View full abstract
-
Makoto ONODERA
Article type: Article
Session ID: 537
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A technique for generating medial-surface and beam model-that is used to transform a solid-model into a medial-surface and beam model for FEM-was developed. The technique has two features. First, medial-surface including ribs and bumps can be generated by recognizing the face-to-face relation of a thin structure. Second, beam model can be generated by recognizing topological profile and depth path of a beam structure. This technique can reduce the workload in generating an analysis model for a solid-model. Furthermore, the developed technique was applied to the generation of analysis model of an overhead baggage rack of railcar and the effectiveness of this technique was confirmed.
View full abstract
-
Masashi Endo
Article type: Article
Session ID: 538
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The present paper describes the next generational structural and fluid analysis solver. Now we develop a mesh less type analysis solver using MPS, Moving Particle Semi-implicit method and DEM, Distinct element method. As we also use together the reverse engineering that acquires data using no contact 3D measuring instruments, we increase an effectiveness of this mesh less method.
View full abstract
-
Huawei CHEN, Ichiro HAGIWARA, Yabo HU
Article type: Article
Session ID: 539
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Chemical vapor deposition (CVD) is gradually emphasized as one promising method for nanomaterial formation. Such growth mechanism has been mainly investigated on basis of experiment. Due to large cost of the equipment of experiment and low level of current measurement, the comprehension about authentic effect of formation condition on properties of nanomaterial is limited in qualitative manner. In this simulation, parallel molecular dynamics simulation was developed and three quantitative items: flatness of primary deposition, adhesion between cluster and substrate, and degree of epitaxial growth were proposed to evaluate the property of thin film. As the case study, three different cluster sizes of 203, 653, 1563 atoms with different velocities (0, 10, 100, 1000, 3000m/s) were deposited on a Cu (001) substrate whose temperatures were set between 300 and 1000K. The results indicated that the property of thin film could be controlled if the effect of situations of process was made clear.
View full abstract
-
Irina SEMENOVA, Zouqi WU, Ichiro HAGIWARA, Junichi SHINODA
Article type: Article
Session ID: 540
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Many different algorithms for surface mesh optimization with different results were proposed recently, but without analysis and comparison it is impossible to choose the method best suited for the particular problem. So unlike other papers, we do not present any new algorithm for mesh optimization here, instead we introduce a framework for thorough analysis of surface mesh optimization results and comparison of different approaches. Proposed tool includes two error-metrics evaluating changes in characteristics and features between surfaces represented by original and resulting meshes. We provide mathematical proof that introduced metrics are sensitive to degradation or diffusion of the essential surface features and therefore could be effectively used to determine degree of deviation between input and output meshes of the optimization algorithm. As an example the proposed tool is used to compare three different techniques, reflecting basic ideas of approaches to surface mesh improvement problem.
View full abstract
-
Zouqi WU, Irina SEMENOVA, Ichiro HAGIWARA, Junichi SHINODA
Article type: Article
Session ID: 541
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this paper, we introduce a new approach to surface mesh improvement problem. In contrast to previous methods we do not tend to preserve new mesh vertices on the original discrete surface. Instead our technique keeps mesh nodes very close to a smooth or piecewise-smooth surface approximated by an initial mesh. As a result, the algorithm is able to improve mesh quality while preserving essential surface characteristics and features. Proposed approach can be applied iteratively not only to polygonal meshes but also to 2D and 3D curves that allow to treat sharp edges and surface boundaries. We demonstrate effectiveness of our method using various triangular and quadrilateral meshes. Also we compare our algorithm with some commonly used techniques and analyze their advantages and disadvantages..
View full abstract
-
Chunhua Sun, Ichiro Hagiwara, Zhuoqi Wu
Article type: Article
Session ID: 542
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Keisuke HAYABUSA, Takashi TAKEMURA, Kenji AMAYA, Keisuke ABE
Article type: Article
Session ID: 615
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Hiroshi Oiwa, Yoshinobu Asano, Hiroyuki Matsumoto, Teruo Matsuzawa
Article type: Article
Session ID: 616
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We developed the real-time visualization system, which is using Jini technology and UNICORE. Jini technology is provides an environment for creating dynamically networked components. UNICORE is a grid middleware, and can use computer resources effectively. The user can easily check the result about calculation of CFD in the middle of calculation by the built system.
View full abstract
-
Yosuke KONDO, Takahiko TANAHASHI
Article type: Article
Session ID: 617
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The use of the electromagnetic pump that drives sodium by the electromagnetic force is expected in the FBR system. However, a large size pumps is not put to practical use because of magnetohydrodynamical instability. In This study, the coupled FEM of electromagnetic field and incompressible fluid by using Magnetic vector potential FEM and GSMAC-FEM is proposed, and the system of electromagnetic pump is calculated by this scheme. Instability characteristics with large size pump are considered from the electromotive force by the motion and Lorentz force.
View full abstract
-
Kazuhiko KAKUDA, Nobuyoshi TOSAKA
Article type: Article
Session ID: 618
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The application of a finite element scheme to full three-dimensional incompressible viscous flow around an impulsively started circular cylinder is presented in this paper. The scheme is based on the Petrov-Galerkin weak formulation with exponential weighting functions. The incompressible Navier-Stokes equations are numerically integrated in time by using a fractional step strategy with second-order accurate Adams-Bashforth scheme for both advection and diffusion terms. Numerical results demonstrate the workability and the validity of the present approach.
View full abstract
-
Norio KONDO
Article type: Article
Session ID: 619
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We present numerical results for aerodynamic vibrations of two circular cylinders in side-by-side arrangement, which are located in a uniform flow. The two closed circular cylinders in numerical computations are arranged in various spacing between the cylinders. It is well known from experimental data that the characteristics of fluid forces acting on the circular cylinders vary depending on the spacing between the cylinders. The computed results at the Reynolds number 1000 are quantitatively compared with the experimental results, and the features of vibrations of two closed cylinders are shown under the biased gap flow.
View full abstract
-
Hiroaki TANAKA, Yasuaki KAI, Juhachi ODA, Tomohiro ITOU, Hiroto YASUDA
Article type: Article
Session ID: 620
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The resin material such as polycarbonates (PC) is considered as the new impact materials such as windshields of automobiles. But, the material has the weak point of rigidity. Then, it is proposed that PC resin is composed with the glass fiber. In this research, the impact penetration fracture when the impact body collides with the center of the PC Laminated Sheet is analyzed. This behavior is analyzed by using the Distinct Element Method (DEM). DEM is suitable for the analysis of the fracture behavior from the non-individual body to the break-up body. In addition to the analysis, the experiment is performed by using an actual material. The analytical result and the experiment are compared From the results, it has been understood that the effect of the outside layer is large and accumulating is not effective.
View full abstract
-
Naohito Nakasato, Tsuyoshi Hamada
Article type: Article
Session ID: 621
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The Smoothed Particle Hydrodynamics (SPH) method is a widely used particle simulation scheme in astrophysical hydrodynamics simulations. Since a possible problem size of SPH simulations is limited by available computational resource, it is natural to implement a computation intensive core of the SPH simulations on a FPGA based reconfigurable board. We are now implementing SPH simulations on our FPGA based board PROGRAPE. Our "SPH processors", which compute particle interaction force by reduced accuracy floating-point operations, run at 133MHz on our board. Obtained peak performance of the SPH processors is 〜 90 Gflops. Our results indicate using FPGA board for floating-point intensive astrophysical simulations is being feasible.
View full abstract
-
Ken-ichi SAITOH, Masato TANAKA, Hayato FUKUMOTO, Noboru SHINKE
Article type: Article
Session ID: 622
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Fracture mechanism of interface in metal-ceramics (silicon carbide: SiC) composite material is investigated by molecular dynamics (MD) and smoothed particle hydrodynamics (SPH) methods. In SPH elastic-plastic analysis, a specimen with U-shape notches is subjected to tensile loading and exhibits the fracture in metal region. Distance from interface plane to actual fracture surface depends largely on the ratio of yield strength to Young's modulus of metal. Nano-scale MD computation model of SiC-Al welded on (001) planes is subjected to tensile loading as well. Obvious deformation does not observed in SiC region at all and plastic deformation in aluminum region leads to breakage of the specimen. Though the fracture in SPH is supposed to be caused not only by stress concentration but also by numerical tensile instability, we can find that our MD results support adequacy of physical view about the interface fracture obtained by SPH.
View full abstract
-
Ken-ichi TSUBOTA, Shigeo WADA, Takami YAMAGUCHI
Article type: Article
Session ID: 623
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A two-dimensional computer simulation of blood flow between parallel plates was carried out using particle method to investigate effects of red blood cells (RBCs) on blood flow properties. The RBCs and plasma were discretized by the particles that have the characteristics of the elastic membrane and the viscous incompressible fluid, respectively. The simulation results demonstrated that apparent blood flow resistance was affected by hematocrit (HCT) that controlled degree of deformation of RBCs. The lower HCT led to the lower resistance because the RBCs were more concentrated in the center of flow channel due to their larger deformation.
View full abstract
-
Masayuki Tanaka, Seiichi Koshizuka
Article type: Article
Session ID: 624
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A red blood cell (RBC) which is ordinarily a biconcave shape can be deformed by external forces. The dynamic property of RBC membrane is modeled by stretching springs and bending springs. In this model, RBC is surrounded by a fluid in three dimensions and the membrane interacts with the fluid using the MPS method. It was shown that the stretching spring constant Kl and the bending spring constant Kb relate to the shape of RBC, and the biconcave shape appears when Kl=1.0×10^<-6> [N/m] and Kb=1.0×10^<-12> [N].
View full abstract
-
Kenichiro NOZAKI, Seiichi KOSHIZUKA
Article type: Article
Session ID: 625
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Virtual surgery needs fluid-structure coupled analysis with large deformation of human tissue. We developed a numerical method for fluid-structure interaction using a particle method. The method is based on weak coupling between fluid and structure analyses. A simple test problem shows that the fluid weight is properly transferred to the structure. Cutting of a blood vessel was analyzed and bleeding appeared with large deformation of the blood vessel.
View full abstract
-
Junya IMAMURA, Takahiko TANAHASHI
Article type: Article
Session ID: 626
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We have proposed a CFD scheme using Helmholtz-element, which is based on Helmholtz's theorem and has many advantages to CFD: for example, the continuity condition can be satisfied algebraically. We apply voxel-elements to simplify to handle the system, since the basis function requires C_1-continuity. In this report, we propose a boundary fitting-technique for the voxel element applying patch system, which is constructed with eight elements (tour elements in 2D). The method is valid as a numerical integration technique of the physical domain such as FCM to keep high accuracy in general.
View full abstract
-
Shoichi FURUYAMA
Article type: Article
Session ID: 627
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The field of the physical oceanography and the coastal engineering, the flood tide and the big wave often becomes object of research interesting. To analyze these phenomenons, the CFD method is the robust and the effective tool. The realization of the complete CFD simulations will bring a solution to prevent the disasters from above tide, and may give the new ideas of the preservation for the coastal environment. Adaptive Mesh Refinement (AMR) is one of the most effective methods, in a special, for decreasing a number of grids and keeping the high accuracy, it has a lot of advantages.
View full abstract
-
Kazue FUJIWARA, Takayuki AOKI, Takanobu OGAWA
Article type: Article
Session ID: 628
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The fragmentation of the structure by explosions is one of crucial problems for safety studies, and well known to be a very difficult subject. The interaction between the blast wave and the probabilistic destruction of the structure has to be solved. The strong pressure of the shock wave makes the structure broken into a lot of small fragments. In the numerical simulation, fine resolution is required locally and moves with the fragmentation process. We have developed a higher-order AMR (IDO-AMR) based on IDO (Interpolated Differential Operator) scheme. We apply our scheme to the fragmentation of the structure driven by a blast wave. The fine resolution is controlled not only for the shock wave but also for the area around small fragments to account for the detail interactions. The destruction of the structure is described by the Extended Distinct Element Method. In this paper, the destruction of a simple-structured material will be presented.
View full abstract
-
Masako IWATA, Kenji ONO, Tsuyoshi TAMAKI
Article type: Article
Session ID: 629
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper describes the comparison of octree data structure intending to find a suitable one for the simulation with a solution adaptive octree mesh. We compared three different kind of implementation of octree, such as Standard, FTT and Pedigree FTT that we proposed, performing simulation programs of a steady-state heat transfer problem. It was found that Pedigree FTT appeared to be most suitable among them from the view points of memory utilization and calculation cost.
View full abstract
-
Minoru SHIRAZAKI, Kenji ONO, Yutaka OHTAKE, Shigeho NODA
Article type: Article
Session ID: 630
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A newly developed method of shape representation, the multi-level partition of unity (MPU) implicit surface, is applied to a moving boundary problem in voxel Cartesian grid. The MPU implicit surface allows us to construct surface models from very large sets of points with normal and polygon. An octree subdivision method is adapted to variations in the complexity of the local shape in the MPU. The MPU has a good compatibility with Cartesian based flow solvers having octree data structure. Combinations of the MPU and the shape approximation in Cartesian based flow solvers are discussed.
View full abstract
-
T. Ogawa, E. S. Oran
Article type: Article
Session ID: 631
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Flux-Corrected Transport (FCT) algorithms have been implemented on an adaptively refined Cartesian mesh. The adaptive mesh is organized with a Fully Threaded Tree, which is a compact and fast data structure. We investigate the behavior of FCT at a mesh-refinement boundary where neighboring cell sizes differ by a factor of two. This reveals that a linear interpolation for the convective flux of FCT improves the accuracy. Numerical tests show that FCT captures a sharp gradient and generates no spurious wave at a mesh-refinement boundary. We also present a computational result with the solution adaptive technique.
View full abstract
-
Yoshihiro HIROKAWA, Minoru YAMADA, Haruki NISHI
Article type: Article
Session ID: 632
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The oil piping was cracked by ground motions of the 2003 Tokachi-oki earthquake. A big fire occurred by the oil leakage from the crack on the tank yard. Investigation into the cause of the fire requires the understanding of the behavior of the piping during the earthquake. In this study, earthquake response analysis was conducted to obtain the displacement and the stress of the piping during the earthquake. This analysis used the actual earthquake waves which were observed on the tank yard. Also, the large deformation analysis was conducted in order to consider the depth of the defect in the piping.
View full abstract
