Energetic Criterion of Material Vibration-fatigue Failure

Author(s):  
A. BOZHKO ◽  
A. FEDOROV ◽  
V. PERMYAKOV
2021 ◽  
pp. 109963622110204
Author(s):  
Zhi-Wei Wang ◽  
Yang-Zhou Lai ◽  
Li-Jun Wang

The bending fatigue tests of single-wall and double-wall corrugated paperboards were conducted to obtain the εrms– N curves under sinusoidal and random loads in this paper. The εrms– N equation of corrugated paperboard can be described by modified Coffin–Manson model considering the effect of mean stress. Four independent fatigue parameters are obtained for single-wall and double-wall corrugated paperboards. The εrms– N curve under random load moves left and rotates clockwise compared with that under sinusoidal load. The fatigue life under random load is much less than that under sinusoidal load, and the fatigue design of corrugated box should be based on the fatigue result under random load. The stiffness degradation and energy dissipation of double-wall corrugated paperboard before approaching fatigue failure are very different from that of single-wall one. For double-wall corrugated paperboard, two turning points occur in the stiffness degradation, and fluctuation occurs in the energy dissipation. Different from metal materials, the bending fatigue failure of corrugated paperboard is a process of wrinkle forming, spreading, and folding. The results obtained have practical values for the design of vibration fatigue of corrugated box.


2014 ◽  
Vol 494-495 ◽  
pp. 142-145
Author(s):  
Chao Yang ◽  
Shou Ne Xiao ◽  
Tao Zhu

Traditional fatigue analysis approaches could not solve the structure fatigue failure caused by resonances. The time domain simulation approach which took the structural intrinsic property into account was presented to solve vibration fatigue problems. The vibration fatigue failure of the frame of vehicle equipment was studied. Broadband vibration loads were put into the finite element model of the frame as excitations, the stress power spectral density of a dangerous point was calculated. At last, the Dirlik method and the time domain simulation approach were used to calculate the fatigue life. The results show that the damage caused by the first-order vertical flexural vibration is the largest; the result of the time domain simulation approach has a good agreement with the experimental result when compared with the frequency domain method.


2018 ◽  
Vol 190 ◽  
pp. 12002
Author(s):  
Bernd Maier ◽  
Markus Klingler ◽  
Sabine Böhm ◽  
Birgit Awiszus

This paper presents the results of an analysation of forming damage during the joining process on the fatigue failure behaviour of a clinched connection. The two joining partners out of aluminium, AlMg0.7Si on the punch side and AlMg3 on the die side, are clinched with a flat clinching system and the use of a preformed hole at the die side. By the use of two different geometry variants it could be shown, in fatigue Wöhler tests, that the fatigue failure behaviour is influenced by the material damage in the deformed material of the clinch. The material damage during the clinching process could be calculated with the help of FE-Simulations. So it was possible to show that more forming damage during the joining process causes less lifetime of the connection.


2014 ◽  
Vol 505-506 ◽  
pp. 319-322
Author(s):  
Wen Shan Wang ◽  
Hua Jie Wu ◽  
Zai Xiang Zheng ◽  
Jing Xu

the compressor bracket of car air conditioner frequently breaks and fatigue failure of its welding beam frequently occur in the vibration fatigue test. In order to solve these problems, the static stress and displacement distribution of mounting bracket are given under the effect of different acceleration by using FEM software in the paper. Simulation results show that revised design of the mounting bracket achieves success and its stiffness, strength and fatigue life satisfy the requirements of vibration test.


2020 ◽  
Vol 62 (6) ◽  
pp. 626-632
Author(s):  
Ashish Gupta ◽  
Vikas Rastogi ◽  
Loveleen Kumar Bhagi

2020 ◽  
Vol 67 (1) ◽  
pp. 111-115
Author(s):  
Sergey A. Voynash ◽  
Viktoriya A. Sokolova ◽  
Viktor I. Kretinin ◽  
Viktor A. Markov ◽  
Elena A. Alekseeva Alekseeva ◽  
...  

One of the main factors that determine the resistance of blade working bodies against damage under dynamic loads is their resistance to plastic crumpling, brittle or fatigue failure. Hard alloys that strengthen the blades of tillage parts are more brittle materials than steel, so the blunting of their edges is caused by the formation of cracks, their gradual growth or microchipping, even from a possible single impact of a solid inclusion in the soil. In addition to the usual brittle fracture of hard alloys, fatigue failure occurs under cyclic impact conditions. (Research purpose) The research purpose is in identifying the pattern of destruction of the blade edge of soil-cutting parts of forestry machines and theoretically justifying the algorithm for assessing the strength to determine the rational thickness of the wear-resistant coating during hardening. (Materials and methods) The article presents the main regularities of the influence of material properties and geometric parameters of the blade on the radius of rounding. (Results and discussion) The process of breaking the edge of the blade of hardened working bodies of forestry machines has been studied. The claim that the blunting of the blades is mainly due to its destruction and not to wear has been proved. The article presents a method for evaluating the strength of bimetallic blades of soil-cutting parts of forestry machines. It was found that the blunting of the blade occurs as a result of edge destruction in the process of multiple impacts of solid soil inclusions along the edge of the blade. (Conclusions) The article shows that the destruction of the edge of the blade leads to blunting of soil-cutting parts, which affects their performance. It was found that the sharpness of a self-sharpening hardened blade is determined by the thickness of the reinforcing layer and its ability to resist destruction under impact.


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