Analysis of Crack Growth Behavior in A Polymeric Strip using Photo-Viscoelastic Method

使用光粘弹性方法分析聚合物条中的裂纹扩展行为

• 批准号: 03650087
• 负责人: TAKASHI Masahisa
• 金额: $ 1.34万
• 依托单位: AOYAMA GAKUIN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03650087/
• 关键词: Photo-Viscoelasticity; Scattered Light Method; Stress Function; Crack; Loading History; Stress Intensity Factor; I-integral; High Polymer; 光粘随性

In order to perform accurate analysis of stress and strain field around a moving tip of crack particalarly in viscoelastic materials, it should be emphasized that not only convenient and useful computer-aided algorithms but also techniques for handling image data of tremendous amounts have to be developed.1) In this study, we developed a convenient algorithm for computer-aided stress analysis of the integrated fringe. The authors proposed a convenient technique to analyze the variation of the stress intensity factor K_I of CT type specimen from plane strain to plane stress state over the thickness of spesimen using a system with the improved devices of the Scattered Light Photoelasticity. Regarding to K_<III>, we can also be successful for accurate measurement in the same manner.2) This study is concerned with a proposal of the functional approximation method to overcome the difficulty in analysis stress distribution near a singular point such as a crack tip and loading. Collapsed data … More of photoelastic fringe pattern in the neighborhood of a singular point will be well reconstructed, using a general form of Goursat stress functions, unknown parameters of which are determined by a nonlinear optimizing approximation technique. And, as an typical example, the stress intensity factor determined as one of the unknown parameters is successfully obtained by applying this method to a Mode I type cracked specimen.3) Taking the time dependent mechanical behavior of the material into consideration, variation of crack growth behavior after changing displacement rate as several steps in length of crack growth is studied. Time dependent J'_I(t) and change in fracture surface roughness are investigated to proceed discussions on relationship between macro- and microscopic mechanisms of fracture taking molecular and entanglement structures of the material into consideration. Then, a new model of crack growth mechanism in sub-micro scale dimension is proposed to describe the time and temperature dependent behavior of crack growth in these materials. Less

为了准确地分析特别是粘弹性材料中裂纹移动尖端周围的应力和应变场，不仅需要开发方便实用的计算机辅助算法，而且还需要开发处理大量图像数据的技术。1)本研究开发了一种方便的综合条纹计算机辅助应力分析算法。本文提出了一种利用改进的散射光弹性装置分析CT型试样应力强度因子K_I随试样厚度从平面应变状态到平面应力状态变化的简便方法。对于K_<III>，我们也可以用同样的方法成功地进行精确测量。2)本文提出了一种泛函近似方法，以克服分析裂纹尖端和载荷等奇点附近应力分布的困难。利用一般形式的Goursat应力函数，通过非线性优化逼近技术确定未知参数，可以很好地重建奇点附近的更多光弹性条纹图。作为一个典型的例子，将该方法应用于I型裂纹试件，成功地获得了作为未知参数之一的应力强度因子。3)考虑材料的力学行为随时间的变化，研究了以裂纹扩展长度为几个步骤，改变位移速率后裂纹扩展行为的变化。研究了随时间变化的J′_I(t)和断口表面粗糙度的变化，并考虑了材料的分子结构和缠结结构，讨论了断裂的宏观机制和微观机制之间的关系。然后，提出了一种新的亚微观尺度裂纹扩展机制模型，以描述这些材料的裂纹扩展随时间和温度的变化规律。少

项目成果

Kazuo OGAWA: "Crack Growth Behavior and Fracture Surface Characteristics of Viscoelastic Epoxy Resin." Proc.of the 7th Int.Congr.on Experimental Mechanics. 1396-1401 (1992)

Kazuo OGAWA：“粘弹性环氧树脂的裂纹扩展行为和断裂表面特性。”

Akihiro KATOH: "CHALLENGE OF 3-DIMENSIONAL STRESS ANALYSIS BY COMPUTER- AIDED SCATTERED LIGHT PHOTOELASTICITY" Proc.of the 1992 Annual Meeting of JSME/MMD. 35-36 (1992)

Akihiro KATOH：“计算机辅助散射光光弹性对 3 维应力分析的挑战”1992 年 JSME/MMD 年会议程。

Makoto Hara: "FUNCTIONAL APPROXIMATION METHOD FOR ANALYSIS OF COLLAPSED PHOTOELASTIC IMAGE DATA AROUND STRESS SINGULARITY" Proc.of the 14th Symposium on Photoelasticity. 513-518 (1992)

Makoto Hara：“应力奇异性周围塌陷光弹性图像数据分析的函数近似方法”第 14 届光弹性研讨会论文集。

饒 健: "散乱光法に関する2,3の試み" 日本光弾性学会講演論文集. 33-36 (1991)

饶健：《关于散射光法的一些尝试》日本光弹性学会会刊33-36（1991）。

Kazuo OGAWA: "Evaluation of crack growth resistance and fracture surface characteristics in several epoxy resins." Proc.of the 6th Int.Conf.Mechanical Behavior of Materials. Vol.4. 105-110 (1991)

Kazuo OGAWA：“评估几种环氧树脂的裂纹扩展阻力和断裂表面特性。”