Solution of stress intensity factor of surface cracked geometry with clamped ends
-
摘要: 为了进行试验室条件下表面裂纹扩展行为研究,需要进行试验机夹持边界条件下的表面裂纹应力强度因子求解.通过对夹持特点的分析,将其等效为均匀拉伸和弯矩的共同作用,并使得试件端部转角为0°.以自由均匀拉伸和纯弯载荷作用下表面裂纹应力强度因子解的Newman-Raju公式为基础,计算得到了等效模型弹性位能表达式,应用卡氏第一定理求得了弯矩与拉伸载荷的关系,采用叠加原理得到了夹持边界条件下表面裂纹应力强度因子解.为了验证解的适用性,采用Abaqus软件计算得到夹持边界条件下若干典型表面裂纹的应力强度因子数值解,对比表明了提出的应力强度因子解法是足够精确的.随后探讨了裂纹形状、试件长厚比等对夹持边界条件下应力强度因子修正因子的影响规律.Abstract: Determination of the stress intensity factor (SIF) of surface cracked geometry with clamped ends is necessary for crack growth analysis in laboratory. Based on the feature of the clamped ends, the clamped condition was simplified as a combined uniform tension stress and bending moment act with the rotation angles of the specimen ends retained to be zero. The elastic potential energy of the equivalent model was derived based on Newman-Raju expression of SIF for surface crack under free uniform tension and bending moment, and then the function relationship between the uniform tension stress and the bending moment was deduced using Castigliano's first theorem. By superposition, the SIF expression of the equivalent model was given. To verify the validity of the expression, SIF solutions of some representative surface cracked geometry with clamped ends were obtained by Abaqus. Comparisons indicate that the expression is accurate enough. In addition, the relationship of crack shape and length-to-thickness ratio to the modifying factor for clamped ends was analyzed.
-
Key words:
- surface crack /
- stress intensity factor /
- clamped ends /
- superposition principle /
- finite element method
-
[1] 郭万林,于培师.构件三维断裂与疲劳力学及其在航空工程中的应用[J].固体力学学报,2010(5):553-571 Guo Wanlin,Yu Peishi.Three dimensional fracture and fatigue mechanics of structures and its application in aeronautical engineering[J].Chinese Journal of Aeronautics,2010(5):553-571(in Chinese) [2] 郭万林.复杂环境下的三维疲劳断裂[J].航空学报,2002,23(3):215-220 Guo Wanlin.Three dimensional fatigue fracture in complex environment[J].Acta Aeronautica et Astronautica Sinica,2002,23(3):215-220(in Chinese) [3] Newman Jr J C,Raju I S.An empirical stress-intensity factor equation for the surface crack[J].Engineering Fracture Mechanics,1981,15(1):185-192 [4] Fett T.Estimation of stress intensity factors for semi-elliptical surface cracks[J].Engineering Fracture Mechanics,2000,66(4):349-356 [5] Wang X,Lambert S B.Stress intensity factors for low aspect ratio semi-elliptical surface cracks in finite-thickness plates subjected to nonuniform stresses[J].Engineering Fracture Mechanics,1995,51(4):517-532 [6] Wang X,Lambert S B.Stress intensity factors and weight functions for high aspect ratio semi-elliptical surface cracks in finite-thickness plates[J].Engineering Fracture Mechanics,1997,57(1):13-24 [7] Wang X,Lambert S B.Semi-elliptical surface cracks in finite-thickness plates with built-in ends.I.Stress intensity factor solutions[J].Engineering Fracture Mechanics,2001,68(16):1723-1741 [8] Wang X,Lambert S B.Semi-elliptical surface cracks in finite-thickness plates with built-in ends.II.Weight function solutions[J].Engineering Fracture Mechanics,2001,68(16):1743-1754 [9] John R,Rigling B.Effect of height to width ratio on K and CMOD solutions for a single edge cracked geometry with clamped ends[J].Engineering Fracture Mechanics,1998,60(2):147-156 [10] John R,Kaldon S G,Johnson D A,et al.Weight function for a single edge cracked geometry with clamped ends[J].International Journal of Fracture,1985,72(2):145-158 [11] Blatt D,John R,Coker D.Stress intensity factor and compliance solutions for a single edge notched specimen with clamped ends[J].Engineering Fracture Mechanics,1994,47(4):521-532 [12] Jones I S.A wide range weight function for a single edge cracked geometry with clamped ends[J].Ineternational Journal of Fracture,1998,89(1):1-18 [13] 单辉祖.材料力学(II)[M].3版.北京:高等教育出版社,2009:35-71 Shan Huizu.Mechanics of materials(II)[M].3rd ed.Beijng:Higher Education Press,2009:35-71(in Chinese) [14] 吴志学.表面裂纹疲劳扩展的数值模拟(II)[J].应用力学学报,2007,24(1):42-46 Wu Zhixue.Numercal simulation to surface crack fatigue growth(II)[J].Chinese Journal of Applied Mechanics,2007,24(1):42-46(in Chinese) [15] 张行.断裂力学[M].北京:宇航出版社,1990:164-169 Zhang Xing.Fracture mechanics[M].Beijing:Aerospace Press,1990:164-169(in Chinese) [16] 林晓斌,Smith R A.应用三维有限单元法计算应力强度因子[J].中国机械工程,1998,9(11):39-42 Lin Xiaobin,Smith R A.Calculation of stress intensity factors using the 3D finite element method[J].China Mechanical Engineering,1998,9(11):39-42(in Chinese)
点击查看大图
计量
- 文章访问数: 1419
- HTML全文浏览量: 192
- PDF下载量: 60828
- 被引次数: 0