scholarly journals Nonlinear Dynamics of a Vibratory Cone Crusher with Hysteretic Force and Clearances

2011 ◽  
Vol 18 (1-2) ◽  
pp. 3-12 ◽  
Author(s):  
Jing Jiang ◽  
Qing-Kai Han ◽  
Chao-Feng Li ◽  
Hong-Liang Yao ◽  
Shu-Ying Liu

Based on the analysis on crushing process and hysteresis of material layers, a hysteretic model with symmetrical clearances is presented. The mechanical model of two-degree of freedom with bilinear hysteresis and its dynamical equations of system are proposed. In order to further investigate the dynamic characteristics of the novel vibratory cone crusher, the system is also simplified into a dynamical system of single degree of freedom with a bilinear hysteretic component together with clearances. According to some nonlinear dynamic analysis tools such as bifurcation diagram, Lyapunov exponents, Poincare section, etc., different motion patterns of the system are discussed, including periodic, periodic doubling, chaos and other characteristics. These theoretical results will provide readers with deep understanding on the regular and complex dynamical behaviors of the vibratory cone crusher due to the hysteresis with clearances.

2012 ◽  
Vol 22 (05) ◽  
pp. 1250110 ◽  
Author(s):  
GUILIN WEN ◽  
HUIDONG XU ◽  
LU XIAO ◽  
XIAOPING XIE ◽  
ZHONG CHEN ◽  
...  

Vibro-impact systems with intermittent contacts are strongly nonlinear. The discontinuity of impact can give rise to rich nonlinear dynamic behaviors and bring forth challenges in the modeling and analysis of this type of nonsmooth systems. The dynamical behavior of a two-degree-of-freedom vibro-impact system is investigated experimentally in this paper. The experimental apparatus is composed of two spring-linked oscillators moving on a lead rail. One of the two oscillators connected to an excitation system intermittently impacts with a spherical obstacle fixed on the thick steel wall. With different gap sizes between the impacting oscillator and the obstacle, the dynamical behaviors are investigated by changing the excitation frequencies. The experimental results show periodic, grazing and chaotic dynamical behaviors of the vibro-impact system.


2020 ◽  
Author(s):  
Aml Ghanem

COVID-19 is a global crisis that requires a deep understanding of infection pathways to facilitate the development of effective treatments and vaccines. Telomere, which is regarded as a biomarker for other respiratory viral infections, might influence the demographic distribution of COVID-19 infection and fatality rates. Viral infection can induce many cellular remodeling events and stress responses, including telomere specific alterations, just as telomere shortening. In brief, this letter aims to highlight the connection between telomere shortening and susceptibility to COVID-19 infection, in addition to changes in telomeric length according to the variation of age and gender of confirmed cases with COVID-19 infection. To sum up, the correlation is revealed from the available data that connect telomere length and COVID-19 infection, demonstrated in the fact that the elderly patients and males are more susceptible to COVID-19 due to shortening in their telomere length.


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