金属学报  1981, Vol. 17 Issue (1): 73-82

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线弹性破断时复合型裂纹顶端塑性区的研究

高桦;张晓堤

中国科学院力学研究所;中国科学院力学研究所

A STUDY ON THE PLASTIC ZONE AHEAD OF MIXED-MODE CRACK TIP FRACTURED UNDER LINEAR ELASTIC CONDITION

Gao Hua and Zhang Xiaodi (Institute of Mechanics; Academia Sinica)

高桦;张晓堤. 线弹性破断时复合型裂纹顶端塑性区的研究[J]. 金属学报, 1981, 17(1): 73-82.
, . A STUDY ON THE PLASTIC ZONE AHEAD OF MIXED-MODE CRACK TIP FRACTURED UNDER LINEAR ELASTIC CONDITION[J]. Acta Metall Sin, 1981, 17(1): 73-82.

摘要 参考文献 相关文章 Metrics 全文: PDF(747 KB)   摘要: 本文基于超高强度钢复合型脆断的实验结果,利用线弹性近似分析和弹塑性有限元分析,对不同的K_(Ⅱ)/K_Ⅰ值脆断的试样,在临界状态时裂纹顶端的塑性区进行了研究,得到了裂纹起始扩展时塑性区的形状和尺寸、裂纹顶端周围应力、应变以及应变能密度的分布情况。根据这些结果,对复合型裂纹扩展阻力的影响因素提出了看法,对现有的复合型断裂准则做了讨论。 Abstract：The crack-tip plastic zone in mixed-mode brittle fractured specimens of different K_Ⅱ/K_Ⅰ ratio of a high strength steel has been investigated under critical conditions. Both elastic approximate analysis and elastic-plastic finite element method were used to analyze the distribution of stress, strain and strain energy density in the vicinity of the crack-tip. It is shown that:(1) at the initial moment of crack growth, the (σ_θ)_(cr) and S_(cr) are notmaterial parameters, but increase with K_Ⅱ/K_Ⅰ;(2) for all specimens fractured under linear elastic condition, the crack tip plastic zone area of mode Ⅱ is larger than that of mode Ⅰ by two order of magnitude and the total plastic work absorbed before brittle fracture markedly increases with K_Ⅱ/K_Ⅰ;(3) the higher the K_Ⅱ/K_Ⅰ ratio is, the lower the σ_m/(?) in the vicinity of crack tip and initial growth directions;(4) under mode Ⅰ condition, the area of the plane stress plastic zone at specimen surface is larger than that of the plane strain plastic zone at the centre of the same specimen by a factor of 3. However, with the increase of K_Ⅱ component, their difference decreases. Therefore, the influence of thickness on mixed-mode brittle fracture toughness might be smaller than on mode Ⅰ.Besides, the increase of hydrostatic tension stress under plane stress condition is quite different from that under plane strain condition. Once the crack tip zone falls into plastic state, the increase rate of the hydrostatic tension stress in the plane stress crack tip zone will become gentle instantaneously, but scarcely any such change would be observed under plane strain condition. It seems that at the initial growth moment the hydrostatic tension stress in the plane stress plastic zone is much smaller than in the plane strain plastic zone. 收稿日期: 1981-01-18      服务 把本文推荐给朋友 加入引用管理器 E-mail Alert RSS 作者相关文章 高桦 张晓堤 44.8K 链接本文: https://www.ams.org.cn/CN/      或      https://www.ams.org.cn/CN/Y1981/V17/I1/73 [1] 高桦、王自强、杨成寿、周爱华、金属学报,15(1979) ,380． [2] Ueda, Y. and Iked, K., Advances in Research on the Strength and Fracture of Materials, Vol. 2A. ed. by D. M. R. Taplin, 4th In ter. Conf. Fracture, 1977 Univ. of Waterloo, New York, Pergamon, 1978, p. 173． [3] Wilson, W. K., Clark, W. G. and Wessel, E, T,, AD 682754, 1968． [4] Sih, G. C., Mechanics of Fracture, Vol. 1, ed. by G. C. Sih, Noorhoff Inter. Publ., Leyden, 1973, p.XLI. [5] Wang, T. C. (王自强),Advances in Research on the Strength and Fracture of Materials, Vol. 4, ed. by D. M. R. Taplin, 4th Inter. Conf. Fracture,1977 Univ. of Waterloo, New York, Pergamon,1978, p.135． [6] Weiss, V. and Yukawa, S.,Amer.Soc.Test. Mater.,Spec.Tech. Publ.,№ 381, 1964, p. 1． [7] Judy, R. W. Jr., and Goode, R. J., Amer. Soc. Test. Mater.,Spec.Tech. Publ., № 527, 1973, p.48． [8] 张晓堤,二维裂纹体的弹塑性有限元介,待发表工作。 No related articles found! Viewed Full text Abstract Cited   Shared      Discussed