Evaluation of Stress Intensity Factor for Cylindrically Anisotropic Material under Mode I, II and III Loadings by Caustics Method

焦散法评估 I、II、III 型载荷下圆柱各向异性材料的应力强度因子

• 批准号: 14550092
• 负责人: SHOZU Masayuki
• 金额: $ 0.9万
• 依托单位: Maizuru National College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550092/
• 关键词: Caustics Method; Cylindrical Anisotropy; Stress Intensity Factor; Initial Curve; 3D Stress Field; Orthotropy; 3D Finite Element Method; Direct simulation; コースティック法; 直接シミュレーション

The stress intensity factors under mode I, II and III loadings are measured by caustics method, and the effect of those loading modes on the measurement accuracy is experimentally and numerically examined. Furthermore, a numerical method based on the 3D finite element method (3D-FEM), which can directly simulate the caustic images, is proposed. As a result, it is found that the minimum initial curve radius r_o^min obtained in this study depends on the type of loading that is of mode I or mode II. In the case of modeIII loading, however, the measured value of K agrees with the theoretical one regardless of the change of the initial curve radius r_o. And the simulated results are in good agreement with the experimental images.On the other hand, the caustics method is examined for an orthotropic Japanese cypress material under mode I loading by using a coating technique, and the results are compared with those of 3D-FEM. As a result, it is found that the determination of K_I using caustics method is valid for radial, tangential and transverse direction, when the initial curve radius r_o is larger than the minimum initial curve radius r_o^min obtained by this study, and the simulated results are nearly in agreement with the experimental images. Furthermore, there was a close correlation between the size of 3D-stress field and out-of-plane displacement near the notch tip.

采用焦散法测量了ⅰ、ⅱ、ⅲ三种加载模式下的应力强度因子，并对三种加载模式对测量精度的影响进行了实验和数值分析。在此基础上，提出了一种基于三维有限元法（3D- fem）的可直接模拟焦散图像的数值方法。结果发现，本研究得到的最小初始曲线半径r_o^min取决于加载类型是I型还是II型。而在模型iii加载情况下，无论初始曲线半径r_o的变化如何，K的实测值与理论值一致。仿真结果与实验图像吻合较好。另一方面，采用包覆技术对正交各向异性日本柏木材料在I型载荷下的焦散进行了分析，并与三维有限元分析结果进行了比较。结果表明，当初始曲线半径r_o大于本研究得到的最小初始曲线半径r_o^min时，用焦散度法测定K_I在径向、切向和横向上都是有效的，模拟结果与实验图像基本一致。此外，三维应力场的大小与缺口尖端附近的面外位移密切相关。

项目成果

生水 雅之: "コースティックス法による異方性材の応力拡大係数の測定"第34回応力・ひずみ測定と強度評価シンポジウム講演論文集,(社)日本非破壊検査協会. 21-26 (2003)

Masayuki Sumizu：“使用焦散法测量各向异性材料的应力强度因子”第34届应力/应变测量和强度评估研讨会论文集，日本无损检测协会21-26（2003）。

生水 雅之: "コースティックス法によるヒノキ材の応力拡大係数の測定に及ぼす採取方向の影響"第35回応力・ひずみ測定と強度評価シンポジウム講演論文集,(社)日本非破壊検査協会. 31-36 (2004)

Masayuki Sumizu：“取样方向对通过焦散法测量柏木应力强度因子的影响”第35届应力/应变测量和强度评估研讨会论文集，日本无损检测协会31 -36（2004）。

"Measurement of Stress Intensity Factor for Orthotropic Material by Caustics Method"Proceedings of 34th symposium on Stress-strain Measurement and Strength Evaluation. 21-26 (2003)

《焦散法测量正交各向异性材料的应力强度因子》第34届应力应变测量与强度评估学术研讨会论文集。

"Study on Measurement of Stress Intensity Factor for Woods by Caustics Method"Proceedings of the 2003 Annual Meetings of the JSME/MMD. No. 03-11. 235-236 (2003)

“焦散法测量木材应力强度因子的研究”JSME/MMD 2003年年会论文集。

"Experimental and Numerical Examination on Measurement of Stress Intensity Factors under Mode I, II and III Loadings by the Method of Caustics"Journal of the Society of Materials Science, Japan. Vol. 52, No. 12. 1496-1501 (2003)

“通过焦散法测量模式 I、II 和 III 载荷下的应力强度因子的实验和数值检验”日本材料学会杂志。