Nondestructive Evaluation of Mechanical Properties and Strength in Repeatedly Prestrained Weldment by Ultrasonic Techniques

利用超声波技术无损评估反复预应变焊件的机械性能和强度

• 批准号: 11650746
• 负责人: ODA Isamu
• 金额: $ 2.3万
• 依托单位: Kumamoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650746/
• 关键词: Bonded Dissimilar Plate; Explosion Welding; Crack-Tip Stress Field; Stress Intensity Factor; Infrared Thermography; Crack Opening Displacement; Fracture Strength; Fracture Mechanics; 予ひずみ; 非破壊評価

An explosion clad plate composed of copper and mild steel is dealt with as a typical example of the bonded dissimilar plate. Tensile tests are carried out using rectangular plate specimens extracted from the clad plate. An artificial through-the-thickness edge crack or parallel cracks are made in each specimen. The cracks are close and perpendicular to the explosive interface. When a tensile load is applied perpendicularly to the crack plane, stress field near cracks, stress intensity factor, crack opening displacement and fracture strength are examined by experiment as well as elasto-plastic finite element analysis. The stress field and the stress intensity factor are evaluated by an infrared stress imaging system. The effects of the material inhomogeneity, the residual stress, the change of material characteristics and the interaction of parallel cracks on the stress field, the stress intensity factor, the deformation behavior and the fracture strength are revealed. The lower strength material ahead of the bonded interface increases the stress intensity factor and the crack opening displacement. The higher strength material ahead of the bonded interface decreases the stress intensity factor and the crack opening displacement. The effects of the material inhomogeneity and the interaction of parallel cracks on the crack opening displacement can be explained from the square of stress intensity factor at the low applied stress level. The brittle fracture strength of the inhomogeneous specimen can be evaluated from the stress intensity factor and linear elastic fracture mechanics criterion.

由铜和碳钢组成的爆炸板板作为键合板的典型例子。使用从外壳板中提取的矩形板样本进行拉伸测试。每个标本中都会制作人造的厚度边缘裂纹或平行裂缝。裂缝是近距离的，垂直于爆炸界面。当垂直于裂纹平面施加拉伸负荷时，通过实验以及弹性塑料有限元分析检查了裂缝附近的应力场，应力强度因子，裂纹开口位移和断裂强度。通过红外应力成像系统评估应力场和应力强度因子。材料不均匀性，残余应力，材料特征的变化以及应力场上平行裂纹的相互作用，应力强度因子，变形行为和断裂强度。粘合界面前的较低强度材料会增加应力强度因子和裂纹开口位移。粘合界面前的较高强度材料降低了应力强度因子和裂纹开口位移。材料不均匀性的影响以及平行裂纹对裂纹开口位移的相互作用可以从低施加的应力水平下的应力强度因子的平方来解释。可以从应力强度因子和线性弹性断裂力学标准中评估不均匀标本的脆性断裂强度。

项目成果

Isamu Oda: "effect of Explosion Bonding on Deformation near a Crack in Copper-Clad Mild Steel Plate"Proceedings of the 13^<th> Asian Technical Exchange and Advisory Meeting on Marine Structures,Keelung,Taiwan. 475-484 (1999)

Isamu Oda：“爆炸结合对铜包低碳钢板裂纹附近变形的影响”第 13 届亚洲海洋结构技术交流和咨询会议论文集，台湾基隆。

Isamu Oda: "Deformation near an Edge Crack Close to the Material-Separation Slit"Proceedings of 13^<th> Asian Technical Exchange and Advisory Meeting on Marine Structures, Keelung. 233-240 (1999)

Isamu Oda：“靠近材料分离狭缝的边缘裂纹附近的变形”第 13 届亚洲海洋结构技术交流和咨询会议论文集，基隆。

Isamu Oda: "Crack-Tip Stress Field Measured by Infrared Thermography and Fracture Strength in Bonded Dissimilar Plate"Quarterly Journal of the Japan Welding Society. 18-3. 487-495 (2000)

Isamu Oda：“通过红外热成像法测量焊接异种板的裂纹尖端应力场和断裂强度”，日本焊接学会季刊。

Isamu oda: "Deformation near a Edge Crack Close to the Material-Separation Slit"Proceedings of 13^<th> Asian Technical Exchange and Advisory Meeting on Marine Structures, Keelung. 233-240 (1999)

Isamu oda：“靠近材料分离狭缝的边缘裂纹附近的变形”第 13 届亚洲海洋结构技术交流和咨询会议论文集，基隆。

小田勇: "異材接合体におけるき裂近傍の赤外線画像応力場と破壊強度"溶接学会論文集. 18・3. 487-495 (2000)

Isamu Oda：“异种金属接头裂纹附近的红外图像应力场和断裂强度”日本焊接学会会议记录 18・3（2000 年）。