变幅载荷作用下的疲劳寿命预测一直是焊接结构完整性评估的重要内容. 基于Pavlou提出的疲劳损伤区概念，采用BS7608标准中推荐的S-N曲线，运用有限元热传导分析技术，提出了一种焊接结构疲劳寿命的预测方法. 针对承载型十字焊接接头、非承载型十字焊接接头和对接焊接接头，开展了二级变幅载荷谱块的拉伸疲劳试验，分别采用Miner模型、M-H模型和Pavlou方法估算了试件的疲劳寿命. 结果表明，Pavlou方法的预测精度明显高于其它2种模型，预测寿命与试验寿命误差散射图中数据点的分布形态更加合理，验证了Pavlou方法的精确性和有效性. 进一步讨论了焊接接头S-N曲线存活率对疲劳寿命预测精度的影响，提出2.3%存活率可以获得较为满意的预测结果.
Fatigue life prediction under variable amplitude loading is an important issue in the integrity analysis of welded structures. Based on the fatigue damage zone concept proposed by Pavlou and the S-N curve recommended in BS7608 standard, an approach to predict fatigue lives of welded structures was realized by FEA heat transfer problem. Fatigue tests under two-level tensile loading block sequences were conducted for load-carrying cruciform welded joints, non-load- carrying cruciform welded joints and butt welded joints, respectively. The fatigue lives of the specimens were estimated according to Miner model, M-H model and Pavlou method. Results showed that the Pavlou method had higher prediction accuracy with more uniform distribution in the error scatter diagram of predicted life versus test life, which validated the rationality and effectiveness of the proposed method. Moreover, the influence of S-N curve survival probability on the life prediction accuracy is discussed. The S-N curve with 2.3% survival probability is suggested to be utilized to obtain satisfactory prediction results.
[1] 成立夫, 魏国前, 胡珂, 等. 基于FIP的焊趾短裂纹行为仿真[J]. 焊接学报, 2020, 41(12): 7-12
Cheng Lifu, Wei Guoqian, Hu Ke, et al. Simulation of short crack behavior of welding toe based on FIP[J]. Transactions of the China Welding Institution, 2020, 41(12): 7-12
[2] 刘苏超, 姜长杰, 刘新田. 基于强度退化的金属材料疲劳寿命预估[J]. 机械强度, 2021, 43(3): 742-746
Liu Suchao, Jiang Changjie, Liu Xintian. Fatigue life prediction of metal materials based on strength degradation[J]. Journal of Mechanical Strength, 2021, 43(3): 742-746
[3] Manson S S, Halford G R. Practical implementation of the double linear damage rule and damage curve approach for treating cumulative fatigue damage[J]. International Journal of Fracture, 1981, 17(2): 169-192.
[4] 薛齐文, 杜秀云, 王生武. 基于载荷加载次序的疲劳寿命预测改进模型[J]. 中国铁道科学, 2019, 40(1): 88-93
Xue Qiwen, Du Xiuyun, Wang Shengwu. Improved fatigue life prediction model based on loading sequence[J]. China Railway Science, 2019, 40(1): 88-93
[5] Gao K, Tang W, Liu G. An improved Manson-Halford model for multi-level nonlinear fatigue life prediction[J]. International Journal of Fatigue, 2021, 151: 106393.
[6] 洪海铭, 詹志新, 王佳莹. 基于损伤力学的增材制造金属材料疲劳寿命预测[J]. 北京航空航天大学学报, 2022, 48(6): 950-956
Hong Haiming, Zhan Zhixin, Wang Jiaying. Fatigue life prediction of metal materials manufactured by additive based on damage mechanics[J]. Journal of Beijing University of Aeronautics and Astronautics, 2022, 48(6): 950-956
[7] Stanisław M. Energy-based method of fatigue damage cumulation[J]. International Journal of Fatigue, 2019, 121: 73-83.
[8] Subramanyan S. A cumulative damage rule based on the knee point of the S-N curve[J]. Journal of Engineering Materials and Technology, 1976, 98(4): 316-321.
[9] Hashin Z, Rotem A. A cumulative damage theory of fatigue failure[J]. Materials Science and Engineering, 1978, 34(2): 147-160.
[10] Pavlou D G. The theory of the S-N fatigue damage envelope: Generalization of linear, double-linear, and non-linear fatigue damage models[J]. International Journal of Fracture, 2018, 110: 204-214.
[11] Murugan R, Venugobal R P, Ramaswami P T, et al. Studies on the effect of weld defect on the fatigue behavior of welded structures[J]. China Welding, 2018, 27(1): 53-59.
[12] 陈秉智, 何正平, 李向伟, 等. 某构件焊缝疲劳开裂的寿命预测方法应用对比[J]. 焊接学报, 2022, 43(5): 63-68
Chen Bingzhi, He Zhengping, Li Xiangwei, et al. Comparison of life prediction methods for fatigue cracking of welded joints of a member[J]. Transactions of the China Welding Institution, 2022, 43(5): 63-68
[13] The British Standards Institution, BS 7608: 2014. Standard B, Guide to fatigue design and assessment of steel products[S]. London: BSI, 2014.
[14] 王苹, 裴宪军, 钱宏亮, 等. 焊接结构抗疲劳设计新方法与应用[J]. 机械工程学报, 2021, 57(16): 349-360
Wang Ping, Pei Xianjun, Qian Hongliang, et al. New fatigue design method and application of welded structures[J]. Journal of Mechanical Engineering, 2021, 57(16): 349-360
