{"title":"Crack shape evolution of single edge through cracked specimens under mode-I loading","authors":"Yongfang Li, Mingming Ren, Hao Chen, Yali Yang, Sha Xu, Ruoping Zhang","doi":"10.1007/s00419-024-02705-3","DOIUrl":null,"url":null,"abstract":"<div><p>Crack shape evolution of single edge through cracked specimens under mode-I loading is studied by means of theoretical analysis, numerical simulation and experimental investigation. Firstly, based on the Paris formula and taking into account the effective stress intensity factor range ratio (<i>U</i>), which characterizes the degree of crack closure, a modified crack growth rate equation is derived. Then, taking the 10 mm thick Al 6061-T6 alloy plate as an example, numerical simulation analysis is conducted. The shape change of crack front during crack propagation is characterized by tunnel depth and surface angle. Finally, fatigue crack growth test is conducted adopting the crack front marking technique to validate the simulation results. The results indicate that the crack growth rate is mainly controlled by the maximum stress intensity factor (<i>K</i><sub>max</sub>) and the <i>U</i> under a certain stress ratio (<i>R</i>). The crack propagation mainly includes two stages, the initial crack propagation stage and the stable crack propagation stage. During the initial crack propagation stage, the crack growth rate in the central layer is greater than that in the surface layer. After approximately 4 mm of crack growth in the central layer, the crack propagation enters the stable stage. In the stable crack propagation stage, the growth rate of the entire crack front is similar, and the shape of the crack front remains almost unchanged.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 1","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Archive of Applied Mechanics","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s00419-024-02705-3","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
Abstract
Crack shape evolution of single edge through cracked specimens under mode-I loading is studied by means of theoretical analysis, numerical simulation and experimental investigation. Firstly, based on the Paris formula and taking into account the effective stress intensity factor range ratio (U), which characterizes the degree of crack closure, a modified crack growth rate equation is derived. Then, taking the 10 mm thick Al 6061-T6 alloy plate as an example, numerical simulation analysis is conducted. The shape change of crack front during crack propagation is characterized by tunnel depth and surface angle. Finally, fatigue crack growth test is conducted adopting the crack front marking technique to validate the simulation results. The results indicate that the crack growth rate is mainly controlled by the maximum stress intensity factor (Kmax) and the U under a certain stress ratio (R). The crack propagation mainly includes two stages, the initial crack propagation stage and the stable crack propagation stage. During the initial crack propagation stage, the crack growth rate in the central layer is greater than that in the surface layer. After approximately 4 mm of crack growth in the central layer, the crack propagation enters the stable stage. In the stable crack propagation stage, the growth rate of the entire crack front is similar, and the shape of the crack front remains almost unchanged.
通过理论分析、数值模拟和实验研究,研究了单边贯通裂纹试样在模态 I 加载下的裂纹形状演变。首先,以巴黎公式为基础,考虑到表征裂纹闭合程度的有效应力强度因子范围比(U),推导出修正的裂纹增长率方程。然后,以 10 毫米厚的 Al 6061-T6 合金板为例,进行了数值模拟分析。裂纹扩展过程中裂纹前沿的形状变化由隧道深度和表面角度表征。最后,采用裂纹前沿标记技术进行了疲劳裂纹生长试验,以验证模拟结果。结果表明,裂纹增长速度主要受最大应力强度因子(Kmax)和一定应力比(R)下的 U 控制。裂纹扩展主要包括两个阶段,即初始裂纹扩展阶段和稳定裂纹扩展阶段。在初始裂纹扩展阶段,中心层的裂纹增长速度大于表层。在中心层裂纹增长约 4 毫米后,裂纹扩展进入稳定阶段。在稳定的裂纹扩展阶段,整个裂纹前沿的增长速度相似,裂纹前沿的形状几乎保持不变。
期刊介绍:
Archive of Applied Mechanics serves as a platform to communicate original research of scholarly value in all branches of theoretical and applied mechanics, i.e., in solid and fluid mechanics, dynamics and vibrations. It focuses on continuum mechanics in general, structural mechanics, biomechanics, micro- and nano-mechanics as well as hydrodynamics. In particular, the following topics are emphasised: thermodynamics of materials, material modeling, multi-physics, mechanical properties of materials, homogenisation, phase transitions, fracture and damage mechanics, vibration, wave propagation experimental mechanics as well as machine learning techniques in the context of applied mechanics.