A new exact and universal conformal mapping is proposed. Using Muskhelishvili's complex potential method, the plane elasticity problem of power function curved cracks is investigated with an arbitrary power of a natu...A new exact and universal conformal mapping is proposed. Using Muskhelishvili's complex potential method, the plane elasticity problem of power function curved cracks is investigated with an arbitrary power of a natural number, and the general solutions of the stress intensity factors (SIFs) for mode I and mode II at the crack tip are obtained under the remotely uniform tensile loads. The present results can be reduced to the well-known solutions when the power of the function takes different natural numbers. Numerical examples are conducted to reveal the effects of the coefficient, the power, and the projected length along the x-axis of the power function curved crack on the SIFs for mode I and mode II.展开更多
Based on the dipole source method, all components of the Green's functions in spectral domain are restructured concisely by four basis functions, and in terms of the two-level discrete complex image method (DCIM) w...Based on the dipole source method, all components of the Green's functions in spectral domain are restructured concisely by four basis functions, and in terms of the two-level discrete complex image method (DCIM) with the high order Sommerfeld identities, an efficient algorithm for closed-form Green's functions in spatial domain in multilayered media is presented. This new work enjoys the advantages of the surface wave pole extraction directly carried out by the generalized integral path without troubles of that all components of Green's function in spectral domain should be reformed respectively in transmission line network analogy, and then the Green's functions for mixed-potential integral equation (MPIE) analysis in both near-field and far-field in multilayered media are obtained. In addition, the curl operator for coupled field in MPIE is avoided conveniently. It is especially applicable and useful to characterize the electromagnetic scattering by, and radiation in the presence of, the electrically large 3-D objects in multilayered media. The numerical results of the S-parameters of a microstrip periodic bandgap (PBG) filter, the radar cross section (RCS) of a large microstrip antenna array, the characteristics of scattering, and radiation from the three-dimensional (3-D) targets in multilayered media are obtained, to demonstrate better effectiveness and accuracy of this technique.展开更多
基金supported by the National Natural Science Foundation of China(Nos.10932001,11072015, and 10761005)the Scientific Research Key Program of Beijing Municipal Commission of Education (No.KZ201010005003)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20101102110016)the Ph.D.Innovation Foundation of Beijing University of Aeronautics and Astronautics(No.300351)
文摘A new exact and universal conformal mapping is proposed. Using Muskhelishvili's complex potential method, the plane elasticity problem of power function curved cracks is investigated with an arbitrary power of a natural number, and the general solutions of the stress intensity factors (SIFs) for mode I and mode II at the crack tip are obtained under the remotely uniform tensile loads. The present results can be reduced to the well-known solutions when the power of the function takes different natural numbers. Numerical examples are conducted to reveal the effects of the coefficient, the power, and the projected length along the x-axis of the power function curved crack on the SIFs for mode I and mode II.
基金the National Natural Science Foundation of China (Grant No. 60371020)National Defense Pre-research Foundation of China (Grant No. 9140a03020206dz0112)
文摘Based on the dipole source method, all components of the Green's functions in spectral domain are restructured concisely by four basis functions, and in terms of the two-level discrete complex image method (DCIM) with the high order Sommerfeld identities, an efficient algorithm for closed-form Green's functions in spatial domain in multilayered media is presented. This new work enjoys the advantages of the surface wave pole extraction directly carried out by the generalized integral path without troubles of that all components of Green's function in spectral domain should be reformed respectively in transmission line network analogy, and then the Green's functions for mixed-potential integral equation (MPIE) analysis in both near-field and far-field in multilayered media are obtained. In addition, the curl operator for coupled field in MPIE is avoided conveniently. It is especially applicable and useful to characterize the electromagnetic scattering by, and radiation in the presence of, the electrically large 3-D objects in multilayered media. The numerical results of the S-parameters of a microstrip periodic bandgap (PBG) filter, the radar cross section (RCS) of a large microstrip antenna array, the characteristics of scattering, and radiation from the three-dimensional (3-D) targets in multilayered media are obtained, to demonstrate better effectiveness and accuracy of this technique.