Free Mesh Method: fundamental conception, algorithms and accuracy study

The finite element method (FEM) has been commonly employed in a variety of fields as a computer simulation method to solve such problems as solid, fluid, electro-magnetic phenomena and so on. However, creation of a quality mesh for the problem domain is a prerequisite when using FEM, which becomes a major part of the cost of a simulation. It is natural that the concept of meshless method has evolved. The free mesh method (FMM) is among the typical meshless methods intended for particle-like finite element analysis of problems that are difficult to handle using global mesh generation, especially on parallel processors. FMM is an efficient node-based finite element method that employs a local mesh generation technique and a node-by-node algorithm for the finite element calculations. In this paper, FMM and its variation are reviewed focusing on their fundamental conception, algorithms and accuracy

An analysis of half elliptical surface crack propagation phenomenon with smoothed particle hydrodynamics method

The smoothed particle hydrodynamics (SPH) method was applied to the problem of fatigue crack propagation. The stress singularity characteristics at the crack tip and the stress intensity factor were compared between the SPH results and the reference values. The result of half elliptical surface crack propagation analysis showed smooth crack propagation history and the shape of the analyzed fracture surface was close to that achieved by test. Accordingly, it is concluded that the SPH is a useful tool to analyze the linear elastic fracture mechanics and the fatigue crack propagation

An analysis of three-dimensional non-planar crack propagation phenomenon with smoothed particle hydrodynamics method

In the present study, the non-planar crackpropagation problems in the 3D body are solved, extending our previous study on the smoothed particle hydrodynamics (SPH) method applied to the fatigue crack propagation of the planar cracks in the 3D body. To solve the propagation of the non-planar crack, the crack front particles are given the information of the slope and the position of the crack surface in addition to the crack length. To confirm the validity of the proposed method, a fatigue test of the CT specimen with an additional horizontal hole is carried out and the result is compared with the computed one successfully

Coupled simulation of vibration of violint and sound radiation in concert hall

The vibrations and the sound field around the body of an old violin made by Stradivari are studied in this paper, in which this violin is scanned using a micro-CT scanner to generate a highly precise geometric image. After the noise in the scanned data is eliminated using a computer-assisted design (CAD) software for post-processing, the geometric data are saved in the simulation software. Assuming the orthotropic properties of woods (spruce and maple), the major vibration modes of the violin, such as A0, center bout rotation, B1-, B1+, and the acoustic pressure level at the surface of the violin body are calculated using the finite element method. Next, using the sound pressure distribution at the surface of the instrument, the sound pressure spreading in a rectangular box simulating a concert hall is calculated with the open-source parallel acoustic analysis software: ADVENTURE Sound. It is concluded that the sound pressure from the violin is successfully simulated

Computational performance of Free Mesh Method applied to continuum mechanics problems

The free mesh method (FMM) is a kind of the meshless methods intended for particle-like finite element analysis of problems that are difficult to handle using global mesh generation, or a node-based finite element method that employs a local mesh generation technique and a node-by-node algorithm. The aim of the present paper is to review some unique numerical solutions of fluid and solid mechanics by employing FMM as well as the Enriched Free Mesh Method (EFMM), which is a new version of FMM, including compressible flow and sounding mechanism in air-reed instruments as applications to fluid mechanics, and automatic remeshing for slow crack growth, dynamic behavior of solid as well as large-scale Eigen-frequency of engine block as applications to solid mechanics

International Conference on Computational Mechanics

It is often said that these days there are too many conferences on general areas of computational mechanics. mechanics. and numer ical methods. vJhile this may be true. the his tory of scientific conferences is itself quite short. According to Abraham Pais (in "Subtle is the Lord ...• " Oxford University Press. 1982. p.80). the first international scientific conference ever held was the Karlsruhe Congress of Chemists. 3-5 September 1860 in Karlsruhe. Germany. There were 127 chemists in attendance. and the participants came from Austria. Belgium. France. Germany. Great Britain. Italy. Mexico. Poland. Russia. Spain. Sweden. and Switzerland. At the top of the agenda of the points to be discussed at this conference was the question: "Shall a difference be made between the expressions molecule and atom?" Pais goes on to note: "The conference did not at once succeed in bringing chemists closer together ... It is possible that the older men were offended by the impetuous behavior and imposing manner of the younger scientists" (see references cited in Pais' book). It may be observed that history. in general. repeats itself. However. at ICCM-86 in Tokyo. roughly 500 participants from both the West and the East were in attendance; there were only scholarly exchanges; the young tried to learn from the more experienced. and a spirit of international academic cooperation prevailed

Noise Filtering of Images Using Generalized Singular Spectrum Analysis

There is a noise filtering method for images using Singular Value Decomposition (SVD). This is a method in which pixel values of an image are regarded as elements of a matrix, the image is separated into rough parts and detailed parts by SVD of the matrix and the detailed parts of the image are regarded as noise and removed. Generalized Singular Spectrum Analysis (GSSA) is a method that generalizes SVD to treat more generalized data structures than in SVD. In this research, we present noise filtering methods of images using GSSA