Fatigue Crack Growth Morphology of 2A12-T4 Aluminum Alloy Plate with Different Thicknesses
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摘要: 对不同厚度2A12-T4铝合金单边缺口试样进行了疲劳裂纹扩展试验, 观察了裂纹稳定扩展前沿形貌并用椭圆方程进行了拟合, 得到了椭圆方程拟合参数; 建立了裂纹前沿相对隧道深度与试样厚度之间的数学表达式, 并对裂纹扩展前沿形貌转变的临界厚度进行了预测, 最后进行了试验验证。结果表明:随着试样厚度的增加, 试样表层与中心层裂纹长度的差值逐渐变小, 疲劳裂纹稳定扩展前沿形貌由“隧道”形状逐渐变成与表面垂直的直线形; 裂纹前沿相对隧道深度随试样厚度的增加而减小, 并在厚度为31.5 mm时趋向0, 试验结果证明了预测结果的准确性。
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关键词:
- 疲劳裂纹 /
- 扩展形貌 /
- 临界厚度 /
- 2A12-T4铝合金
Abstract: The fatigue crack growth tests were carried out on the single-edge notched specimens of 2A12-T4 aluminum alloy with different thicknesses. The crack front morphology during stable crack growth was observed and fitted by the elliptic equation, and the fitting parameters of elliptic equation were obtained. The mathematical expression between the relative tunnel depth of crack front and the specimen thickness was established. The critical thickness of the crack front morphology transition during growth was predicted and verified by experiments. The results show that with the increase of the specimen thickness, the difference of crack length between the surface layer and the inner layer gradually decreased. The fatigue crack front morphology during stable crack growth changed gradually from "tunnel" shape to a straight line perpendicular to the surface. The relative tunnel depth of crack front decreased with the increase of the specimen thickness, and tended to 0 with the thickness of 31.5 mm. The test results verified the accuracy of the predicted results.-
Keywords:
- fatigue crack /
- growth morphology /
- critical thickness /
- 2A12-T4 aluminum alloy
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[1] 金江, 盛季生.稳态裂纹扩展前缘形态的研究［J］.工程力学, 2005, 22(s1):62-66. [2] 《工程材料实用手册》编辑委员会.工程材料实用手册［M］.2版.北京:中国标准出版社,2002. [3] 韩丽娟,李小欣,李继承.焊丝对2A12铝合金焊接接头组织和力学性能的影响［J］.机械工程材料,2015,39(3):32-40. [4] 张诗捷,朱亦钢,黄新跃, 等.试件厚度对铝合金疲劳裂纹扩展的影响［J］.航空学报,1994,15(6):757-760. [5] KWON S W,SUN C T.Characteristics of three-dimensional stress fields in plates with a through-the-thickness crack［J］.International Journal of Fracture,2000,104(3):289-314. [6] BRANCO R,ANTUNES F V.Finite element modeling and analysis of crack shape evolution in model:Ⅰfatigue middle cracked tension specimens［J］.Engineering Fracture Mechanics,2008,75(10):3020-3037. [7] BRANCO R,RODRIGUES D M,ANTUNES F V.Influence of through-thickness crack profile on plasticity induced crack closure［J］.Fatigue & Facture of Engineering Materials & Structures,2008,31(2):209-220. [8] 何宇廷, 傅祥炯.铝合金CCT试样裂纹扩展三维尺寸效应金相分析［J］.空军工程大学学报(自然科学版),2002,3(2): 5-8. [9] 高潮, 伍黎明, 何宇廷,等.基于能量模型的三维穿透裂纹扩展研究［J］.航空动力学报,2015,30(3):639-648. [10] 王坤茜.不同应力比下的疲劳裂纹扩展可靠性研究［D］.昆明:昆明理工大学,2012. [11] 涂文锋.16MnR钢疲劳裂纹扩展形貌和扩展路径的试验研究与数值模拟［D］.杭州:浙江工业大学,2009. [12] 徐峰.2024-T4铝合金疲劳裂纹扩展行为的试验研究及数值模拟［D］.杭州:浙江工业大学, 2012. [13] LIN X B,SMITH R A.Finite element modeling of crack growth surface cracked plates part Ⅱ:crack profile change［J］.Engineering Fracture Mechanics,1999,63(5):523-540.
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