The displacement and the stress states cased by single inclusion are achieved from the fundamental solutions such as nuclei of strain in bimaterals. The elastic field induced by multiple inclusions in dissimilar media...The displacement and the stress states cased by single inclusion are achieved from the fundamental solutions such as nuclei of strain in bimaterals. The elastic field induced by multiple inclusions in dissimilar media could be found from the superstition of that of individual precipitate. In this paper, the effect of the planner interface with parameters of depth from the interface, both pairs of elastic moduli and also shapes of the inclusion are also given, which are of great significance in physical applications.展开更多
A computational model is proposed for short-fiber reinforced materials with the eigenstrain formulation of the boundary integral equations （BIE） and solved with the newly developed boundary point method （BPM）. The...A computational model is proposed for short-fiber reinforced materials with the eigenstrain formulation of the boundary integral equations （BIE） and solved with the newly developed boundary point method （BPM）. The model is closely derived from the concept of the equivalent inclusion Of Eshelby tensors. Eigenstrains are iteratively determined for each short-fiber embedded in the matrix with various properties via the Eshelby tensors, which can be readily obtained beforehand either through analytical or numerical means. As unknown variables appear only on the boundary of the solution domain, the solution scale of the inhomogeneity problem with the model is greatly reduced. This feature is considered significant because such a traditionally time-consuming problem with inhomogeneity can be solved most cost-effectively compared with existing numerical models of the FEM or the BEM. The numerical examples are presented to compute the overall elastic properties for various short-fiber reinforced composites over a representative volume element （RVE）, showing the validity and the effectiveness of the proposed computational modal and the solution procedure.展开更多
This paper presents an analytical solution for the elastic fields induced by non-elastic eigenstrains in a plane elliptical inhomogeneity embedded in the orthotropic matrix under tension at infinity and inclined at an...This paper presents an analytical solution for the elastic fields induced by non-elastic eigenstrains in a plane elliptical inhomogeneity embedded in the orthotropic matrix under tension at infinity and inclined at any angle. The conformal transformation and complex function method for the anisotropic elastic material were used to determine the strain energies in the inhomogeneity and matrix, which were expressed by four undetermined coefficients characterizing the equilibrium boundary of the inhomogeneity due to the acting eigenstrains and external load. The use of the principle of the minimum potential energy led to analytical expres-sions for these coefficients and thus generated a closed-form solution for the elas-tic strain/stress fields. The resulting stress field in the inhomogeneity was exam-ined and verified by checking the continuity conditions for the normal and shear stresses on the interior boundary of the matrix.展开更多
Welding residual stress is one of the main concems for fabrication and operation of steel structures due to its potential effect on structural integrity.This paper focuses on the effect of welding residual stress on t...Welding residual stress is one of the main concems for fabrication and operation of steel structures due to its potential effect on structural integrity.This paper focuses on the effect of welding residual stress on the ductile crack growth resistance of circumferentially cracked steel pipes.Two-dimensional axi-symmetry model has been used to simulate the pipe.Residual stresses were introduced into the model by using so-called eigenstrain method.The complete Gurson model has been employed to calculate the ductile crack growth resistance.Results show that residual stresses reduce the ductile crack growth resistance.However,the effect of residual stresses on ductile crack growth resistance decreases with the increase of crack growth.The effect of residual stress has also been investigated for cases with different initial void volume fraction,material hardening and crack sizes.展开更多
文摘The displacement and the stress states cased by single inclusion are achieved from the fundamental solutions such as nuclei of strain in bimaterals. The elastic field induced by multiple inclusions in dissimilar media could be found from the superstition of that of individual precipitate. In this paper, the effect of the planner interface with parameters of depth from the interface, both pairs of elastic moduli and also shapes of the inclusion are also given, which are of great significance in physical applications.
基金Project supported by the National Natural Science Foundation of China (No.10772106)
文摘A computational model is proposed for short-fiber reinforced materials with the eigenstrain formulation of the boundary integral equations （BIE） and solved with the newly developed boundary point method （BPM）. The model is closely derived from the concept of the equivalent inclusion Of Eshelby tensors. Eigenstrains are iteratively determined for each short-fiber embedded in the matrix with various properties via the Eshelby tensors, which can be readily obtained beforehand either through analytical or numerical means. As unknown variables appear only on the boundary of the solution domain, the solution scale of the inhomogeneity problem with the model is greatly reduced. This feature is considered significant because such a traditionally time-consuming problem with inhomogeneity can be solved most cost-effectively compared with existing numerical models of the FEM or the BEM. The numerical examples are presented to compute the overall elastic properties for various short-fiber reinforced composites over a representative volume element （RVE）, showing the validity and the effectiveness of the proposed computational modal and the solution procedure.
基金the Program for New Century Excellent Talents in Universities (NCET) of the Ministry of Education of China (Grant No. NCET-04-0373)the Program for Shanghai Pujiang Talents (Grant No. 05PJ14092)
文摘This paper presents an analytical solution for the elastic fields induced by non-elastic eigenstrains in a plane elliptical inhomogeneity embedded in the orthotropic matrix under tension at infinity and inclined at any angle. The conformal transformation and complex function method for the anisotropic elastic material were used to determine the strain energies in the inhomogeneity and matrix, which were expressed by four undetermined coefficients characterizing the equilibrium boundary of the inhomogeneity due to the acting eigenstrains and external load. The use of the principle of the minimum potential energy led to analytical expres-sions for these coefficients and thus generated a closed-form solution for the elas-tic strain/stress fields. The resulting stress field in the inhomogeneity was exam-ined and verified by checking the continuity conditions for the normal and shear stresses on the interior boundary of the matrix.
基金The financial support from the Research Council of Norway(PETROMAKS Contract No.192967/S60),Statoil,Gassco,Technip and EFD Induction through DEEPIT project is gratefully acknowledged.
文摘Welding residual stress is one of the main concems for fabrication and operation of steel structures due to its potential effect on structural integrity.This paper focuses on the effect of welding residual stress on the ductile crack growth resistance of circumferentially cracked steel pipes.Two-dimensional axi-symmetry model has been used to simulate the pipe.Residual stresses were introduced into the model by using so-called eigenstrain method.The complete Gurson model has been employed to calculate the ductile crack growth resistance.Results show that residual stresses reduce the ductile crack growth resistance.However,the effect of residual stresses on ductile crack growth resistance decreases with the increase of crack growth.The effect of residual stress has also been investigated for cases with different initial void volume fraction,material hardening and crack sizes.
