A new mesh free method proposed by the authors was presented, in which the derivatives at each node were constructed using whole derivative formulas through the nodes selected around the node using local Cartesian fra...A new mesh free method proposed by the authors was presented, in which the derivatives at each node were constructed using whole derivative formulas through the nodes selected around the node using local Cartesian frame in an autonomous manner, so that without any element it could be considered as a completely mesh free method. The method was tested with a numerical example, and reliable solution was obtained with high accuracy and efficiency.展开更多
A meshless and matrix-free fluid dynamics solver(SOMA)is introduced that avoids the need for user generated and/or analyzed grids,volumes,and meshes.Incremental building of the approximation avoids creation and invers...A meshless and matrix-free fluid dynamics solver(SOMA)is introduced that avoids the need for user generated and/or analyzed grids,volumes,and meshes.Incremental building of the approximation avoids creation and inversion of possibly dense block diagonal matrices and significantly reduces user interaction.Validation results are presented from the application of SOMA to subsonic,compressible,and turbulent flow over an adiabatic flat plate.展开更多
A novel numerical method is explored and named as mesh-free poly-cell Galerkin method. An improved moving least-square （MLS） scheme is presented, which can avoid the matrix inversion in standard MLS and can be used ...A novel numerical method is explored and named as mesh-free poly-cell Galerkin method. An improved moving least-square （MLS） scheme is presented, which can avoid the matrix inversion in standard MLS and can be used to construct shape functions possessing delta Kronecher property. A new type of local support is introduced to ensure the alignment of integral domains with the cells of the back-ground mesh, which will reduce the difficult in integration. An intensive numerical study is conducted to test the accuracy of the present method. It is observed that solutions with good accuracy can be obtained with the present method.展开更多
Metal forming plays an important role in manufacturing industry and is widely applied in industries.The tradi- tional finite element method(FEM)numerical simulation is commonly used to predict metal forming process.Co...Metal forming plays an important role in manufacturing industry and is widely applied in industries.The tradi- tional finite element method(FEM)numerical simulation is commonly used to predict metal forming process.Conventional finite element analysis of metal forming processes often breaks down due to severe mesh distortion,therefore time-consuming remeshing is necessary.Meshfree methods have been developed since 1977 and can avoid this problem.This new generation of computational methods reduces time-consuming model generation and refinement effort,and its shape function has higher order connectivity than FEM’s.In this paper the velocity shape functions are developed from a reproducing kernel approximation that satisfies consistency conditions and is used to analyze metal tension rigid viscoplastic deforming and Magnesium Alloy(MB 15)sheet superplastic ten- sion forming.A meshfree method metal forming modeling program is set up,the partition of unity method is used to compute the integrations in weak form equations and penalty method is used to impose the essential boundary condition exactly.Metal forming examples,such as sheet metal superplastic tension forming and metal rigid viscoplastic tension forming,are analyzed to demon- strate the performance of mesh free method.展开更多
In this paper,we analyse the equal width（EW） wave equation by using the mesh-free reproducing kernel particle Ritz（kp-Ritz） method.The mesh-free kernel particle estimate is employed to approximate the displacement...In this paper,we analyse the equal width（EW） wave equation by using the mesh-free reproducing kernel particle Ritz（kp-Ritz） method.The mesh-free kernel particle estimate is employed to approximate the displacement field.A system of discrete equations is obtained through the application of the Ritz minimization procedure to the energy expressions.The effectiveness of the kp-Ritz method for the EW wave equation is investigated by numerical examples in this paper.展开更多
This paper deals with a new nonconforming anisotropic rectangular finite element approximation for the planar elasticity problem with pure displacement boundary condition. By use of the special properties of this elem...This paper deals with a new nonconforming anisotropic rectangular finite element approximation for the planar elasticity problem with pure displacement boundary condition. By use of the special properties of this element, and by introducing the complementary space and a series of novel techniques, the optimal error estimates of the energy norm and the L^2-norm are obtained. The restrictions of regularity assumption and quasi-uniform assumption or the inverse assumption on the meshes required in the conventional finite element methods analysis are to be got rid of and the applicable scope of the nonconforming finite elements is extended.展开更多
Tension-free vaginal mesh (TVM) surgery is a common and minimally invasive procedure for pelvic organ prolapses. Since commercial kits are not readily available in Japan, we have planned tailor-made mesh by informatio...Tension-free vaginal mesh (TVM) surgery is a common and minimally invasive procedure for pelvic organ prolapses. Since commercial kits are not readily available in Japan, we have planned tailor-made mesh by information of each patient before every TVM surgery. The aim of this report is to inform methods to design mesh for individual patients with pelvic organ prolapses. We also investigated the correlations among mesh size and height, weight, and body mass index (BMI). Before the operation, we obtained a KUB (abdominal X-ray). Three factors were measured from this X-ray: the first was the distance between the bilateral ischial spine, the second was the distance between the obturator foramen, and the third was the length of the arcus tendineus fascia pelvis (ATFP). These three factors always should be considered for designing of mesh. The correlations among the bilateral ischial spine distance, obturator foramen distance, ATFP length, height, weight, and BMI were assessed using the Pearson correlation coefficient. Although these three factors described above are necessary to design a mesh for individual patients, the bilateral ischial spine and obturator foramen distance correlated with the height of the patient. On the other hand, since the length of ATFP differs in each patient and is not correlated with height, we should consider this length when we design the mesh. Well-designed, tailor-made mesh will probably fit each pelvic organ prolapsed patient very well.展开更多
AIM:To analyze the clinical features,diagnostic modalities,and the surgical management of urethral complications after tension-free vaginal tape procedures.METHODS:This study encompasses a retrospective review of nine...AIM:To analyze the clinical features,diagnostic modalities,and the surgical management of urethral complications after tension-free vaginal tape procedures.METHODS:This study encompasses a retrospective review of nine patients presented with urethral complications after midurethral sling procedures.The patients underwent the procedures during a period from 1999 to 2012 in three different regional hospitals in the southwest part of Sweden.The time from sling placement to diagnosis,the risk factors,clinical features,diagnosis,surgical management,and functional outcome are presented.The presenting symptoms were described as either early onset(< 12 mo) or late onset(> 12 mo) according to when they were first reported.RESul TS:Eight cases of urethral erosion and one case of bladder-neck erosion were detected.The mean interval for diagnoses of the erosions ranged from 3 mo to 11 years.The most common presenting symptoms included de novo urgency with or without incontinence(7/9 patients),urinary retention/voiding dysfunction(4/9 patients),urethritis(4/9 patients),relapse of stress-incontinence(3/9 patients),recurrent urinary tract infections(5/9 patients),and hematuria(1/9 patient).In most cases,voiding dysfunction and urethritis occurred early after the operation.The surgical management applied in most cases was transurethral resection of the intraurethral part of the mesh.The removal of the intraurethral mesh resulted in improvement or complete cure of urgency symptomsin 5/7 patients with urgency.Four patients were reoperated with a new stress-incontinence surgery,one with laparoscopic Burch,and three with retropubic tension-free vaginal tape procedures.COn Clu SIOn:Urethral complications should be suspected in the case of de novo urgency and relapse of stressincontinence.Transurethral excision of the intraurethral mesh is the recommended treatment.展开更多
The interpolating moving least-squares （IMLS） method is discussed first in this paper. And the formulae of the IMLS method obtained by Lancaster are revised. Then on the basis of the boundary element-free method （B...The interpolating moving least-squares （IMLS） method is discussed first in this paper. And the formulae of the IMLS method obtained by Lancaster are revised. Then on the basis of the boundary element-free method （BEFM）, combining the boundary integral equation （BIE） method with the IMLS method, the improved boundary element-free method （IBEFM） for two-dimensional potential problems is presented, and the corresponding formulae of the IBEFM are obtained. In the BEFM, boundary conditions are applied directly, but the shape function in the MLS does not satisfy the property of the Kronecker ~ function. This is a problem of the BEFM, and must be solved theoretically. In the IMLS method, when the shape function satisfies the property of the Kronecker 5 function, then the boundary conditions, in the meshless method based on the IMLS method, can be applied directly. Then the IBEFM, based on the IMLS method, is a direct meshless boundary integral equation method in which the basic unknown quantity is the real solution of the nodal variables, and the boundary conditions can be applied directly and easily, thus it gives a greater computational precision. Some numerical examples are presented to demonstrate the method.展开更多
基金Project supported by the Nation-al Natural Science Foundation of China(No.10372055)the Shanghai Leading Academic Discipline Project(No.Y0103)
文摘A new mesh free method proposed by the authors was presented, in which the derivatives at each node were constructed using whole derivative formulas through the nodes selected around the node using local Cartesian frame in an autonomous manner, so that without any element it could be considered as a completely mesh free method. The method was tested with a numerical example, and reliable solution was obtained with high accuracy and efficiency.
基金The authors wish to express their appreciation to the reviewers for their helpful suggestions which greatly improved the presentation of this paper。
文摘A meshless and matrix-free fluid dynamics solver(SOMA)is introduced that avoids the need for user generated and/or analyzed grids,volumes,and meshes.Incremental building of the approximation avoids creation and inversion of possibly dense block diagonal matrices and significantly reduces user interaction.Validation results are presented from the application of SOMA to subsonic,compressible,and turbulent flow over an adiabatic flat plate.
文摘A novel numerical method is explored and named as mesh-free poly-cell Galerkin method. An improved moving least-square （MLS） scheme is presented, which can avoid the matrix inversion in standard MLS and can be used to construct shape functions possessing delta Kronecher property. A new type of local support is introduced to ensure the alignment of integral domains with the cells of the back-ground mesh, which will reduce the difficult in integration. An intensive numerical study is conducted to test the accuracy of the present method. It is observed that solutions with good accuracy can be obtained with the present method.
文摘Metal forming plays an important role in manufacturing industry and is widely applied in industries.The tradi- tional finite element method(FEM)numerical simulation is commonly used to predict metal forming process.Conventional finite element analysis of metal forming processes often breaks down due to severe mesh distortion,therefore time-consuming remeshing is necessary.Meshfree methods have been developed since 1977 and can avoid this problem.This new generation of computational methods reduces time-consuming model generation and refinement effort,and its shape function has higher order connectivity than FEM’s.In this paper the velocity shape functions are developed from a reproducing kernel approximation that satisfies consistency conditions and is used to analyze metal tension rigid viscoplastic deforming and Magnesium Alloy(MB 15)sheet superplastic ten- sion forming.A meshfree method metal forming modeling program is set up,the partition of unity method is used to compute the integrations in weak form equations and penalty method is used to impose the essential boundary condition exactly.Metal forming examples,such as sheet metal superplastic tension forming and metal rigid viscoplastic tension forming,are analyzed to demon- strate the performance of mesh free method.
基金Project supported by the Natural Science Foundation of Zhejiang Province,China (Grant No. Y6110007)
文摘In this paper,we analyse the equal width（EW） wave equation by using the mesh-free reproducing kernel particle Ritz（kp-Ritz） method.The mesh-free kernel particle estimate is employed to approximate the displacement field.A system of discrete equations is obtained through the application of the Ritz minimization procedure to the energy expressions.The effectiveness of the kp-Ritz method for the EW wave equation is investigated by numerical examples in this paper.
基金Supported by the National Natural Science Foundation of China(10371113,10671184)
文摘This paper deals with a new nonconforming anisotropic rectangular finite element approximation for the planar elasticity problem with pure displacement boundary condition. By use of the special properties of this element, and by introducing the complementary space and a series of novel techniques, the optimal error estimates of the energy norm and the L^2-norm are obtained. The restrictions of regularity assumption and quasi-uniform assumption or the inverse assumption on the meshes required in the conventional finite element methods analysis are to be got rid of and the applicable scope of the nonconforming finite elements is extended.
文摘Tension-free vaginal mesh (TVM) surgery is a common and minimally invasive procedure for pelvic organ prolapses. Since commercial kits are not readily available in Japan, we have planned tailor-made mesh by information of each patient before every TVM surgery. The aim of this report is to inform methods to design mesh for individual patients with pelvic organ prolapses. We also investigated the correlations among mesh size and height, weight, and body mass index (BMI). Before the operation, we obtained a KUB (abdominal X-ray). Three factors were measured from this X-ray: the first was the distance between the bilateral ischial spine, the second was the distance between the obturator foramen, and the third was the length of the arcus tendineus fascia pelvis (ATFP). These three factors always should be considered for designing of mesh. The correlations among the bilateral ischial spine distance, obturator foramen distance, ATFP length, height, weight, and BMI were assessed using the Pearson correlation coefficient. Although these three factors described above are necessary to design a mesh for individual patients, the bilateral ischial spine and obturator foramen distance correlated with the height of the patient. On the other hand, since the length of ATFP differs in each patient and is not correlated with height, we should consider this length when we design the mesh. Well-designed, tailor-made mesh will probably fit each pelvic organ prolapsed patient very well.
文摘AIM:To analyze the clinical features,diagnostic modalities,and the surgical management of urethral complications after tension-free vaginal tape procedures.METHODS:This study encompasses a retrospective review of nine patients presented with urethral complications after midurethral sling procedures.The patients underwent the procedures during a period from 1999 to 2012 in three different regional hospitals in the southwest part of Sweden.The time from sling placement to diagnosis,the risk factors,clinical features,diagnosis,surgical management,and functional outcome are presented.The presenting symptoms were described as either early onset(< 12 mo) or late onset(> 12 mo) according to when they were first reported.RESul TS:Eight cases of urethral erosion and one case of bladder-neck erosion were detected.The mean interval for diagnoses of the erosions ranged from 3 mo to 11 years.The most common presenting symptoms included de novo urgency with or without incontinence(7/9 patients),urinary retention/voiding dysfunction(4/9 patients),urethritis(4/9 patients),relapse of stress-incontinence(3/9 patients),recurrent urinary tract infections(5/9 patients),and hematuria(1/9 patient).In most cases,voiding dysfunction and urethritis occurred early after the operation.The surgical management applied in most cases was transurethral resection of the intraurethral part of the mesh.The removal of the intraurethral mesh resulted in improvement or complete cure of urgency symptomsin 5/7 patients with urgency.Four patients were reoperated with a new stress-incontinence surgery,one with laparoscopic Burch,and three with retropubic tension-free vaginal tape procedures.COn Clu SIOn:Urethral complications should be suspected in the case of de novo urgency and relapse of stressincontinence.Transurethral excision of the intraurethral mesh is the recommended treatment.
基金Project supported by the National Natural Science Foundation of China (Grant No 10871124)Innovation Program of Shanghai Municipal Education Commission (Grant No 09ZZ99)Shanghai Leading Academic Discipline Project (Grant No J50103)
文摘The interpolating moving least-squares （IMLS） method is discussed first in this paper. And the formulae of the IMLS method obtained by Lancaster are revised. Then on the basis of the boundary element-free method （BEFM）, combining the boundary integral equation （BIE） method with the IMLS method, the improved boundary element-free method （IBEFM） for two-dimensional potential problems is presented, and the corresponding formulae of the IBEFM are obtained. In the BEFM, boundary conditions are applied directly, but the shape function in the MLS does not satisfy the property of the Kronecker ~ function. This is a problem of the BEFM, and must be solved theoretically. In the IMLS method, when the shape function satisfies the property of the Kronecker 5 function, then the boundary conditions, in the meshless method based on the IMLS method, can be applied directly. Then the IBEFM, based on the IMLS method, is a direct meshless boundary integral equation method in which the basic unknown quantity is the real solution of the nodal variables, and the boundary conditions can be applied directly and easily, thus it gives a greater computational precision. Some numerical examples are presented to demonstrate the method.
