在本文中,以 Hill 的塑性理论为基础,详细地讨论了理想正交各向异性弹塑性材料,平面应力条件下Ⅰ型静止裂纹尖端场解。裂纹尖端应力场不包含应力间断线,但包含弹性区。分析的结果表明(i)对于平面应力静止裂纹问题,应力场解不是唯一的,...在本文中,以 Hill 的塑性理论为基础,详细地讨论了理想正交各向异性弹塑性材料,平面应力条件下Ⅰ型静止裂纹尖端场解。裂纹尖端应力场不包含应力间断线,但包含弹性区。分析的结果表明(i)对于平面应力静止裂纹问题,应力场解不是唯一的,场解中的自由参数必须由远场条件来确定。(ii)裂纹尖端的应力、应变的奇异性,无论是各向异性材料还是各向同性材料,都是相同的。但在各向异性材料中,各向异性参数影响着应力、应变的幅度和分布。展开更多
Some possible alternative solutions of near-tip fields are studied for plane-strain Mode-I qua- si-static steady crack growth in incompressible(v=1/2)elastic perfectly-plastic media.A group of four-sector so- lutions ...Some possible alternative solutions of near-tip fields are studied for plane-strain Mode-I qua- si-static steady crack growth in incompressible(v=1/2)elastic perfectly-plastic media.A group of four-sector so- lutions and a three-sector solution in which the elastic-unloading region vanishes are given.Stress functions,plas- tic flow factors and plastic strains in each region are also given.展开更多
Based on the theoretical framework for crack growth analysis provided by Gao and Hwang, the 5-sector soiution of near-tip fields of mode-I cracks growing quasi-statically and steadily in compressible elastic perfectly...Based on the theoretical framework for crack growth analysis provided by Gao and Hwang, the 5-sector soiution of near-tip fields of mode-I cracks growing quasi-statically and steadily in compressible elastic perfectly plastic materials is obtained.As Poisson's ratio v tends to 1/2,the 5-sector solution degener- ates to the 4-sector solution of near-tip fields of crack growth in incompressible elastic perfectly plastic materials.展开更多
The stress and deformation fields near the tip of an anti-plane crack growing quasi-statically along an interface of elastic perfectly plastic materials are given in this paper. A family of solutions for the growing c...The stress and deformation fields near the tip of an anti-plane crack growing quasi-statically along an interface of elastic perfectly plastic materials are given in this paper. A family of solutions for the growing crack fields is found covering all admissible crack line shear stress ratios.展开更多
By means of an asymptotic expansion method of a regular series, an exact higher-order analysis has been carried out for the near-tip fields of an in- terfacial crack between two different elastic-plastic materials. Th...By means of an asymptotic expansion method of a regular series, an exact higher-order analysis has been carried out for the near-tip fields of an in- terfacial crack between two different elastic-plastic materials. The condition of plane strain is invoked. Two group of solutions have been obtained for the crack surface conditions: (1) traction free and (2) frictionless contact, respectively. It is found that along the interface ahead of crack tip the stress fields are co-order continuous while the displacement fields are cross-order continuous. The zone of dominance of the asymptotic solutions has been estimated.展开更多
A higher order asymptotic solution of near-tip field is studied for plane-atrain Mode-Ⅰ quasi-static steady crack growth in the incompressible (v=1/2) elastic perfectly-plastic media.The results show that the near-ti...A higher order asymptotic solution of near-tip field is studied for plane-atrain Mode-Ⅰ quasi-static steady crack growth in the incompressible (v=1/2) elastic perfectly-plastic media.The results show that the near-tip stress and strain are fully continuous,and the strain possesses In (A/r) singularity at the crack tip.The expressions of the stress,strain and velocity in each region are also given.展开更多
In this paper,we present an exact higher-order asymptotic analysis on the near-crack-tip fields in elastic-plastic materials under plane strain,Mode 1.A four- or five-term asymptotic series of the solutions is derived...In this paper,we present an exact higher-order asymptotic analysis on the near-crack-tip fields in elastic-plastic materials under plane strain,Mode 1.A four- or five-term asymptotic series of the solutions is derived.It is found that when 1.6 < n≤2.8 (here,n is the hardening exponent),the elastic effect enters the third-order stress field; but when 2.8< n≤3.7 this effect turns to enter the fourth-order field,with the fifth-order field independent.Moreover,if n>3.7,the elasticity only affects the fields whose order is higher than 4.In this case,the fourth-order field remains independent.Our investigation also shows that as long as n is larger than 1.6,the third-order field is always not independent,whose amplitude coefficient K3 depends either on K1 or on both K1 and K2 (K1 and K2 arc the amplitude coefficients of the first- and second-order fields,respectively).Finally,good agreement is found between our results and O'Dowd and Shih's numerical ones by comparison.展开更多
Studies on near-tip fields constitute one of the central problems in fracture mechanics. This note confines attention to quasi-static steady growth of mode-Ⅰ plane strain crack growing in elastic-perfectly-plastic ma...Studies on near-tip fields constitute one of the central problems in fracture mechanics. This note confines attention to quasi-static steady growth of mode-Ⅰ plane strain crack growing in elastic-perfectly-plastic materials. For the case of incompressible materials (v=1/2), the 4-sector solution (called hereafter 'solution展开更多
文摘在本文中,以 Hill 的塑性理论为基础,详细地讨论了理想正交各向异性弹塑性材料,平面应力条件下Ⅰ型静止裂纹尖端场解。裂纹尖端应力场不包含应力间断线,但包含弹性区。分析的结果表明(i)对于平面应力静止裂纹问题,应力场解不是唯一的,场解中的自由参数必须由远场条件来确定。(ii)裂纹尖端的应力、应变的奇异性,无论是各向异性材料还是各向同性材料,都是相同的。但在各向异性材料中,各向异性参数影响着应力、应变的幅度和分布。
基金Project supported by the State Education Commission under a funding program for Excellent University Young Faculties and National Natural Science Foundation of China.
文摘Some possible alternative solutions of near-tip fields are studied for plane-strain Mode-I qua- si-static steady crack growth in incompressible(v=1/2)elastic perfectly-plastic media.A group of four-sector so- lutions and a three-sector solution in which the elastic-unloading region vanishes are given.Stress functions,plas- tic flow factors and plastic strains in each region are also given.
基金The project supported by the National Natural Science Foundation of China.
文摘Based on the theoretical framework for crack growth analysis provided by Gao and Hwang, the 5-sector soiution of near-tip fields of mode-I cracks growing quasi-statically and steadily in compressible elastic perfectly plastic materials is obtained.As Poisson's ratio v tends to 1/2,the 5-sector solution degener- ates to the 4-sector solution of near-tip fields of crack growth in incompressible elastic perfectly plastic materials.
基金The project supported by the National Natural Science Foundation of China
文摘The stress and deformation fields near the tip of an anti-plane crack growing quasi-statically along an interface of elastic perfectly plastic materials are given in this paper. A family of solutions for the growing crack fields is found covering all admissible crack line shear stress ratios.
基金The project supported by the National Natural Science Foundation of China
文摘By means of an asymptotic expansion method of a regular series, an exact higher-order analysis has been carried out for the near-tip fields of an in- terfacial crack between two different elastic-plastic materials. The condition of plane strain is invoked. Two group of solutions have been obtained for the crack surface conditions: (1) traction free and (2) frictionless contact, respectively. It is found that along the interface ahead of crack tip the stress fields are co-order continuous while the displacement fields are cross-order continuous. The zone of dominance of the asymptotic solutions has been estimated.
基金The project supported by National Natural Science Foundation of China
文摘A higher order asymptotic solution of near-tip field is studied for plane-atrain Mode-Ⅰ quasi-static steady crack growth in the incompressible (v=1/2) elastic perfectly-plastic media.The results show that the near-tip stress and strain are fully continuous,and the strain possesses In (A/r) singularity at the crack tip.The expressions of the stress,strain and velocity in each region are also given.
基金Project supported by the National Natural Science Foundation of China
文摘In this paper,we present an exact higher-order asymptotic analysis on the near-crack-tip fields in elastic-plastic materials under plane strain,Mode 1.A four- or five-term asymptotic series of the solutions is derived.It is found that when 1.6 < n≤2.8 (here,n is the hardening exponent),the elastic effect enters the third-order stress field; but when 2.8< n≤3.7 this effect turns to enter the fourth-order field,with the fifth-order field independent.Moreover,if n>3.7,the elasticity only affects the fields whose order is higher than 4.In this case,the fourth-order field remains independent.Our investigation also shows that as long as n is larger than 1.6,the third-order field is always not independent,whose amplitude coefficient K3 depends either on K1 or on both K1 and K2 (K1 and K2 arc the amplitude coefficients of the first- and second-order fields,respectively).Finally,good agreement is found between our results and O'Dowd and Shih's numerical ones by comparison.
基金Project supported by the National Natural Science Foundation of China.
文摘Studies on near-tip fields constitute one of the central problems in fracture mechanics. This note confines attention to quasi-static steady growth of mode-Ⅰ plane strain crack growing in elastic-perfectly-plastic materials. For the case of incompressible materials (v=1/2), the 4-sector solution (called hereafter 'solution
