湖北大学学报(自然科学版)
湖北大學學報(自然科學版)
호북대학학보(자연과학판)
2015年
2期
127-132
,共6页
杨大鹏%潘海洋%赵耀%李天匀
楊大鵬%潘海洋%趙耀%李天勻
양대붕%반해양%조요%리천균
幂硬化材料%弯曲裂纹%塑性区%二阶摄动方法
冪硬化材料%彎麯裂紋%塑性區%二階攝動方法
멱경화재료%만곡렬문%소성구%이계섭동방법
hardened material%curved crack%plasticity area%a second order perturbation solution
利用二阶摄动方法计算硬化材料弹塑性弯曲裂纹尖端的塑性区尺寸的最大值和和变化幅值。作图分析弹塑性弯曲裂纹尖端塑性区尺寸最大值、变化幅值与材料硬化指数之间的变化关系。在幂硬化材料中,弹塑性弯曲裂纹尖端塑性区尺寸最大值和变化幅值随材料硬化指数n的增大而减少,当n等速均匀增加时,弹塑性弯曲裂纹尖端塑性区尺寸最大值和变化幅值加速减少,减少的幅度越来越大。当材料的硬化指数相同时,弯曲裂纹尖端塑性区尺寸最大值和变化幅值随疲劳载荷的不断减小而逐渐减小。
利用二階攝動方法計算硬化材料彈塑性彎麯裂紋尖耑的塑性區呎吋的最大值和和變化幅值。作圖分析彈塑性彎麯裂紋尖耑塑性區呎吋最大值、變化幅值與材料硬化指數之間的變化關繫。在冪硬化材料中,彈塑性彎麯裂紋尖耑塑性區呎吋最大值和變化幅值隨材料硬化指數n的增大而減少,噹n等速均勻增加時,彈塑性彎麯裂紋尖耑塑性區呎吋最大值和變化幅值加速減少,減少的幅度越來越大。噹材料的硬化指數相同時,彎麯裂紋尖耑塑性區呎吋最大值和變化幅值隨疲勞載荷的不斷減小而逐漸減小。
이용이계섭동방법계산경화재료탄소성만곡렬문첨단적소성구척촌적최대치화화변화폭치。작도분석탄소성만곡렬문첨단소성구척촌최대치、변화폭치여재료경화지수지간적변화관계。재멱경화재료중,탄소성만곡렬문첨단소성구척촌최대치화변화폭치수재료경화지수n적증대이감소,당n등속균균증가시,탄소성만곡렬문첨단소성구척촌최대치화변화폭치가속감소,감소적폭도월래월대。당재료적경화지수상동시,만곡렬문첨단소성구척촌최대치화변화폭치수피로재하적불단감소이축점감소。
Elastic-plastic curved crack tip plasticity area in hardened material under fatigue loads was mainly studied,and maximum and amplitude of curved crack tip plasticity area was calculated as a practical application of a second order perturbation method,where the effects of fatigue applied stresses and fatigue normal and shear stresses on the boundaries of plasticity area were synthetically taken into considerations. Diagrams were constructed to analyze the transformation relationships between maximum or amplitude of curve crack tip plasticity area size and hardening exponents.Maximum and amplitude of curved crack tip plasticity area size will decrease with hardening exponents increasing in hardened material.The decrease extent of maximum and amplitude of curved crack tip plasticity area size will be more and more severe with hardening exponents increasing evenly.Maximum and amplitude of curve crack tip plasticity area size will decrease when maximum and amplitude of fatigue loads decrease with the same hardening exponents.A brand new domain of theoretical model where fatigue curved crack tip plasticity area was calculated was reclaimed in hardened material.