Complex variables method has been used to solve the first and second fundamental problems for an infinite plate weakened by a generalized curvilinear hole C. The curvilinear hole is conformally mapped on the domain ou...Complex variables method has been used to solve the first and second fundamental problems for an infinite plate weakened by a generalized curvilinear hole C. The curvilinear hole is conformally mapped on the domain outside or inside a unit circle γ using a general rational mapping function with complex constants. Many special and new cases are derived from this work. Some of the work of the previous authors in this domain will be considered as special cases of this paper. Also the interesting cases when the shape of the hole takes different famous shapes are included. The components of stresses for some examples are obtained.展开更多
The hatches for inspecting are usually designed with elliptical holes in airplane structures, so computation of the stress intensity factor of three dimensional crack at elliptical holes is pivotal for damage toleranc...The hatches for inspecting are usually designed with elliptical holes in airplane structures, so computation of the stress intensity factor of three dimensional crack at elliptical holes is pivotal for damage tolerance analysis of these structures. In this paper, weight function is derived for a two dimensional through cracks at elliptical holes by applying a compounding method. Stress intensity factor formulas for an internal surface semi-elliptical crack in elliptical holes are obtained wing the three dimensional weight function method. Stress intensity factors for an internal surface semi-elliptical crack in elliptical holes under remote tension are computed. At the same time, research on how radius of curvature for elliptical holes affect stress intensity factors was conducted. Stress intensity factors decrease when radius of curvature increases. Some results and conclusions which are of practical value are given.展开更多
· AIM: To investigate the visual function and the relationship with vision-related quality of life(VRQOL)after macular hole repair surgery.· METHODS: Prospective case series. Thirty-six consecutive eyes in 3...· AIM: To investigate the visual function and the relationship with vision-related quality of life(VRQOL)after macular hole repair surgery.· METHODS: Prospective case series. Thirty-six consecutive eyes in 36 patients who underwent pars plana vitrectomy(PPV) and internal limiting membrane(ILM) peeling were included. The 25-item National Eye Institute Visual Function Questionnaire(VFQ-25) was answered by the participants before and 3 and 12 mo after operation. Follow-up visits examinations included best-corrected visual acuity(BCVA), clinical examination,and central macular thickness(CMT) measured by optical coherence tomography(OCT).·RESULTS: Macular-hole closure was achieved in 35 of36 eyes(97.2%). At baseline and months 3 and 12, the log MAR BCVAs(mean±SD) were 1.15±0.47, 0.68±0.53(P 【0.0001 versus baseline), and 0.55 ±0.49(P 【0.001 versus baseline, P =0.273 versus month 3), respectively; the CMTs(μm) were 330 ±81, 244 ±62(P 【0.001 versus baseline), and 225±58(P 【0.001 versus baseline, P =0.222 versus month 3), respectively; the median preoperative VFQ-25 composite score of 73.50(63.92-81.13) increased postoperatively to 85.50(80.04-89.63) at 3mo(P 【0.001)and 86.73(82.50-89.63) at 12mo(P 【0.001) respectively.The improved BCVA was correlated with improvements in five subscales(r =-0.605 to-0.336, P 【0.001 to P =0.046) at 12 mo.· CONCLUSION: PPV with ILM peeling improved anatomic outcome, visual function, and VRQOL. Theimproved BCVA was an important factor related to the improved VRQOL.展开更多
In this paper, the basic formulae for the semi-analytical graded FEM on FGM members are derived. Since FGM parameters vary along three space coordinates, the parameters can be integrated in mechanical equations. There...In this paper, the basic formulae for the semi-analytical graded FEM on FGM members are derived. Since FGM parameters vary along three space coordinates, the parameters can be integrated in mechanical equations. Therefore with the parameters of a given FGM plate, problems of FGM plate under various conditions can be solved. The approach uses 1D discretization to obtain 3D solutions, which is proven to be an effective numerical method for the mechanical analyses of FGM structures. Examples of FGM plates with complex shapes and various holes are presented.展开更多
Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic...Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic and complex function theory. And then the two stress functions required were founded on Cauchy integral by boundary conditions. The final stress distributions of opening structure and the analytical solution on composite material plate with rectangle hole and wing manholes were achieved. The influences on hole-edge stress concentration factors are discussed under different loads and fiber direction cases, and then contrast calculates are carried through FEM.展开更多
文摘Complex variables method has been used to solve the first and second fundamental problems for an infinite plate weakened by a generalized curvilinear hole C. The curvilinear hole is conformally mapped on the domain outside or inside a unit circle γ using a general rational mapping function with complex constants. Many special and new cases are derived from this work. Some of the work of the previous authors in this domain will be considered as special cases of this paper. Also the interesting cases when the shape of the hole takes different famous shapes are included. The components of stresses for some examples are obtained.
文摘The hatches for inspecting are usually designed with elliptical holes in airplane structures, so computation of the stress intensity factor of three dimensional crack at elliptical holes is pivotal for damage tolerance analysis of these structures. In this paper, weight function is derived for a two dimensional through cracks at elliptical holes by applying a compounding method. Stress intensity factor formulas for an internal surface semi-elliptical crack in elliptical holes are obtained wing the three dimensional weight function method. Stress intensity factors for an internal surface semi-elliptical crack in elliptical holes under remote tension are computed. At the same time, research on how radius of curvature for elliptical holes affect stress intensity factors was conducted. Stress intensity factors decrease when radius of curvature increases. Some results and conclusions which are of practical value are given.
文摘· AIM: To investigate the visual function and the relationship with vision-related quality of life(VRQOL)after macular hole repair surgery.· METHODS: Prospective case series. Thirty-six consecutive eyes in 36 patients who underwent pars plana vitrectomy(PPV) and internal limiting membrane(ILM) peeling were included. The 25-item National Eye Institute Visual Function Questionnaire(VFQ-25) was answered by the participants before and 3 and 12 mo after operation. Follow-up visits examinations included best-corrected visual acuity(BCVA), clinical examination,and central macular thickness(CMT) measured by optical coherence tomography(OCT).·RESULTS: Macular-hole closure was achieved in 35 of36 eyes(97.2%). At baseline and months 3 and 12, the log MAR BCVAs(mean±SD) were 1.15±0.47, 0.68±0.53(P 【0.0001 versus baseline), and 0.55 ±0.49(P 【0.001 versus baseline, P =0.273 versus month 3), respectively; the CMTs(μm) were 330 ±81, 244 ±62(P 【0.001 versus baseline), and 225±58(P 【0.001 versus baseline, P =0.222 versus month 3), respectively; the median preoperative VFQ-25 composite score of 73.50(63.92-81.13) increased postoperatively to 85.50(80.04-89.63) at 3mo(P 【0.001)and 86.73(82.50-89.63) at 12mo(P 【0.001) respectively.The improved BCVA was correlated with improvements in five subscales(r =-0.605 to-0.336, P 【0.001 to P =0.046) at 12 mo.· CONCLUSION: PPV with ILM peeling improved anatomic outcome, visual function, and VRQOL. Theimproved BCVA was an important factor related to the improved VRQOL.
基金Project supported by the National Natural Science Foundation of China (No. 10432030)
文摘In this paper, the basic formulae for the semi-analytical graded FEM on FGM members are derived. Since FGM parameters vary along three space coordinates, the parameters can be integrated in mechanical equations. Therefore with the parameters of a given FGM plate, problems of FGM plate under various conditions can be solved. The approach uses 1D discretization to obtain 3D solutions, which is proven to be an effective numerical method for the mechanical analyses of FGM structures. Examples of FGM plates with complex shapes and various holes are presented.
基金This project is supported by National Natural Science Foundation of China(No.50175031).
文摘Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic and complex function theory. And then the two stress functions required were founded on Cauchy integral by boundary conditions. The final stress distributions of opening structure and the analytical solution on composite material plate with rectangle hole and wing manholes were achieved. The influences on hole-edge stress concentration factors are discussed under different loads and fiber direction cases, and then contrast calculates are carried through FEM.
