蠕变材料Ⅲ型准静态扩展裂纹尖端场构造分析  

Structure analysis of mode Ⅲ quasi-static propagating crack tip field in creeping materials

作　　者：贾斌[1] 李永东[2] 王振清[3] 

机构地区：[1]哈尔滨工业大学复合材料与结构研究所,哈尔滨150001 [2]装甲兵工程学院机械工程系,北京100072 [3]哈尔滨工程大学建筑工程学院,哈尔滨150001

出　　处：《哈尔滨工业大学学报》2007年第3期412-415,共4页Journal of Harbin Institute of Technology

摘　　要：采用弹粘塑性力学模型,对蠕变材料中Ⅲ型准静态扩展裂纹尖端场进行了渐近分析.在线性硬化条件下,裂纹尖端的应力和应变场具有相同的幂奇异性,奇异性指数由材料的粘性系数唯一确定.数值计算结果表明,材料的硬化系数主导裂尖场的分区构造,但二次塑性区对裂尖场的影响较小.材料的粘性主导裂纹尖端应力和应变场的强度,同时对裂尖场的构造有一定影响.当硬化系数为零时,裂尖场退化为粘弹性-理想塑性解.A elastic-viscoplastic mechanics model was adopted to investigate asymptotically the mode Ⅲ quasistatic propagating crack tip field in creeping materials. The stress and strain fields at crack tip possess the same power law singularity under linear-hardening condition. And the singularity exponent is uniquely determined by the viscosity coefficient of the material. The numerical calculation results indicate that the hardening coefficient dominates the structure of crack-tip field but the secondary plastic zone has little influence on the field. The viscosity of the material dominates the strength of stress and strain fields at crack tip while it do has certain influence on crack-tip field structure. The crack-tip field degenerates into the viscoelastic-perfectlyplastic one when the hardening coefficient becomes zero.

关 键 词：蠕变材料 准静态扩展 裂纹尖端场 

分 类 号：O346[理学—固体力学]