Yan Fangping, Lu Hao, Xiao Linjing
College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
Swinburne College, Shandong University of Science and Technology, Jinan, Shandong Province, 250031, China.
Sci Rep. 2024 Aug 23;14(1):19631. doi: 10.1038/s41598-024-70671-5.
The cross beam of a mining linear vibrating screen is prone to cracking under long-term cyclic load. In order to accurately predict the fatigue life of the cracked cross beam, a coupled analysis method of vibration and crack propagation is proposed. A 2D dynamic model of the vibrating screen is established based on the finite element method, which is verified by the vibration test platform. The cracked Euler beam element is used to model the cracked cross beam. The effects of crack depth, amplitude of excitation force, frequency of excitation force, and crack location on the crack-tip stress intensity factor of the cracked cross beam are investigated in detail. In addition, an iterative method is proposed on the basis of the Paris model. The residual service life of the beam under different frequencies of excitation force, amplitudes of excitation force, spring stiffness, crack positions, and degrees of stiffness imbalance are discussed. The results demonstrate that the fatigue life of the beam increases as the frequency of excitation force and spring stiffness increase. The increase of the amplitude of excitation force and spring permanent deformation reduces the fatigue life. The conclusion obtained provide some theoretical guidance for the design and routine maintenance of mining linear vibrating screens.
矿用直线振动筛的横梁在长期循环载荷作用下容易出现裂纹。为了准确预测裂纹横梁的疲劳寿命，提出了一种振动与裂纹扩展的耦合分析方法。基于有限元法建立了振动筛的二维动力学模型，并通过振动试验平台进行了验证。采用裂纹欧拉梁单元对裂纹横梁进行建模。详细研究了裂纹深度、激振力幅值、激振力频率和裂纹位置对裂纹横梁裂纹尖端应力强度因子的影响。此外，在巴黎模型的基础上提出了一种迭代方法。讨论了不同激振力频率、激振力幅值、弹簧刚度、裂纹位置和刚度不平衡度下横梁的剩余使用寿命。结果表明，横梁的疲劳寿命随着激振力频率和弹簧刚度的增加而增加。激振力幅值和弹簧永久变形的增加会降低疲劳寿命。所得结论为矿用直线振动筛的设计和日常维护提供了一定的理论指导。
