摘要
本文用三维弹塑性有限元计算了含表面裂纹均匀拉伸板在不同载荷大小下的弹塑性位移场、应力场和裂纹尖端塑性区等。计算结果表明:裂纹张开位移具有良好的线性段;对称面和前表面不是处于平面应变和平面应力状态,它们的塑性区用二维情况下的Irwin公式估计误差很大;裂纹尖端塑性区随着载荷的增加,后自由表面的影响也增加;体内大部分区域近似于无裂纹的轴向拉伸应力状态,仅在相当靠近裂纹尖端地区才有较强的塑性约束;裂纹顶端的第三维正应力也具有奇异性。这些结果对于表面裂纹的断裂、疲劳特性研究具有一定的参考价值。
The displacements,stresses ,plastic zone size have been calculated by F.E.M. for the tension plate with surface crack under different loads. The results show that the stress state in symmetric plane, and frontal surface plane is neither plane stress nor plane strain, their plastic zone size can't he preedicted precisely with Irwin's formula in 2-dimensional problem, the effects of back free plane on the crack tip plastic zone increase with the increments of loads, most part of the plate is approximately under uniform tension state as a plate without the surface crack, only at the vicinilv of the crack tip these is much plastic constraints, and the third normal stress tangential to the crack front also has singularity at the crack tip. These results are quite useful references for the study of the fracture behavior of surface crack.
出处
《北京航空航天大学学报》
EI
CAS
1986年第3期23-30,共8页
Journal of Beijing University of Aeronautics and Astronautics
