| COMPUTATIONAL SIMULATION |
|
|
|
|
|
| Problem of the Uniform and Variable Speed of Loading About Metal Subjected to Asymmetrical Cycling Loads |
| XIAO Min1, LUO Yingshe1, 3, SI Jiayong2, LIU Xiubo1, 3
|
1 Institute of Rheological Mechanics and Materials Engineering, Central South University of Forestry and Technology,Changsha 410004;
2 School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004;
3 Hunan Province Key Laboratory of Engineering Rheology, Central South University of Forestry and Technology, Changsha 410004 |
|
|
|
|
Abstract According to damage mechanics, fatigue is caused by the evolution of the damage inside the material, but the mec-hanism is not clear. Therefore, the molecular theory of fracture in polymer physics is extended to be applied to metal fatigue damage. It is found that fracture of metal is a relaxation process, and macro fracture is ascribed to a thermal activation of the microscopic atomic bond breaking. Taking Q235 steel as an example,the testing of the tension and compression of asymmetrical cycle is carried on the CMT5105 universal electronic testing machine. From the view of atomic bond dissociation and combined with the experimental data, the concrete form of asymmetrical cycle fatigue damage evolution under the constant and variable loading rates in multiple factors is discussed and deduced. Then a new fatigue damage evolution is proposed by taking the rate as the main consideration, the basic forms of damage evolution under the conditions of constant and variable rates are discussed respectively, and rate dependent parameter factors are modified. The results show that the new fatigue damage evolution is simple in form, few in parameters, wild in application, and is better fitted with the experimental results.
|
|
Published: 25 February 2018
|
|
|
|
|
1 Scerrato D, Giorgio I, Della Corte A, et al. A micro-structural mo-del for dissipation phenomena in the concrete[J].International Journal for Numerical and Analytical Methods in Geomechanics,2015,39(18):2037.
2 肖万伸.含损伤、缺陷复合材料的结构强度及损伤判据研究[R].国防科技大学力学博士后流动站.长沙,2002.
3 Zhang Lei. Finite element simulation and experiment of tensile pro-perties of Q235 steel[D].Changchun:Jilin University,2012(in Chinese).
张磊.Q235钢拉伸性能的有限元仿真与试验[D].长春:吉林大学,2012.
4 Quan Guozheng, Wang Yixin, Zhang Yanwei, et al. Effect of temperature and strain rate on critical damage factors of 7075 aluminum alloy[J].Journal of Chongqing University(Natural Science Edition),2011,34(7):51(in Chinese).
权国政,王熠昕,张艳伟,等.温度及应变速率对7075铝合金临界损伤因子的影响[J].重庆大学学报(自然科学版),2011,34(7):51.
5 Skrzypek J J, Ganczarski A. Modeling of material damage and fai-lure of structures[J].Foundations of Engineering Mechanics,1999,13:155.
6 Chaboche J L. Stress calculations for lifetime prediction in turbine blades[J].International Journal of Solids & Structures,1974,10(5):473.
7 Wang J. A continuum damage mechanics model for low-cycle fatigue failure of metals[J].Engineering Fracture Mechanics,1992,41(3):437.
8 Zheng Z G, Cai G W, Li Z J. A new model of fatigue damage evolution[J].Engineering Mechanics,2010,27(2):37(in Chinese).
郑战光,蔡敢为,李兆军.一种新的疲劳损伤演化模型[J].工程力学,2010,27(2):37.
9 Chen Cen. Development of a elastoplasticity damage constitutive theory and analysis of mechanical behavior of materials[D].Beijing:University of Chinese Academy of Sciences,2013(in Chinese).
陈岑.一种弹塑性损伤本构理论的发展及其对材料力学行为的分析[D].北京:中国科学院大学,2013.
10 Lai B T, Wong H, Fabbri A, et al. A new constitutive model of unsaturated soils using bounding surface plasticity (BSP) and a non-associative flow rule[J].Innovative Infrastructure Solutions,2016,1(1):1.
11 Li Xudong, Liu Zhiguo, Mu Zhitao. Evaluation of fatigue damage of aluminum alloy based on energy dissipation[J].Physical and Chemical Test:Physical Volume,2013(10):647(in Chinese).
李旭东,刘治国,穆志韬.基于能量耗散的铝合金疲劳损伤评价[J].理化检验:物理分册,2013(10):647.
12 Li Bin. Fatigue damage characterization and life prediction based on energy dissipation[D].Xi’an:Northwestern Polytechnical University,2014(in Chinese).
李斌.基于能量耗散的金属疲劳损伤表征及寿命预测[D].西安:西北工业大学,2014. |
|
|
|
渝公网安备50019002502923号 © Editorial Office of Materials Reports.
2018, Vol. 32 
