Study on the Pair’s Characteristics of Web Press’s Fold System in High Speed

2011 ◽  
Vol 311-313 ◽  
pp. 1398-1403
Author(s):  
Ying Cai Yuan ◽  
Yan Li ◽  
Yi Ming Wang

In high speed, the web press’s fold mechanism appears nonlinear dynamic response characteristics, which seriously affect the fold system’s stability and precision. The clearance and roller’s deformation are the main factors to cause the nonlinear dynamic response. To study the influence of clearance and roller’s deformation, the hypothesis of rigid role and spring combination is put forward. Based on the hypothesis, the dynamics model of fold system with clearance is established by kinematics and dynamics analysis. Through the dynamics model of fold system, the situation of pair clearance and roller’s deformation can be obtained, and the influence to the dynamic performance of fold system can be easily got.

Author(s):  
Zhicheng Yang ◽  
Meifung Tam ◽  
Yingyan Zhang ◽  
Sritawat Kitipornchai ◽  
Jiangen Lv ◽  
...  

This paper presents a numerical investigation on the nonlinear dynamic response of multilayer functionally graded graphene platelets reinforced composite (FG-GPLRC) beam with open edge cracks in thermal environment. It is assumed that graphene platelets (GPLs) in each GPLRC layer are uniformly distributed and randomly oriented with its concentration varying layer-wise along the thickness direction. The effective material properties of each GPLRC layer are predicted by Halpin-Tsai micromechanics-based model. Finite element method is employed to calculate the dynamic response of the cracked FG-GPLRC beam. It is found that the maximum dynamic deformation of the cracked FG-GPLRC beam under dynamic loading is quite sensitive to the crack location and grows with an increase in the crack depth ratio (CDR) and temperature rise. The influences of GPL distribution, concentration, geometry as well as the boundary conditions on the dynamic response characteristics of cracked FG-X-GPLRC beams are also investigated comprehensively.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jianyu Zhang ◽  
Peng Liu ◽  
Liyun Fan ◽  
Yajie Deng

A 3D numerical simulation model of high-speed solenoid valve (HSV) for electronic control fuel injection system (ECFIS) has been developed. The model has been validated experimentally with acceptable maximum errors of 2% and 8.7% in closure response time and open response time, respectively. Effect of assembly parameters such as residual air gap, maximum lift of valve stem, mass of the moving parts, spring stiffness, and spring pretightening force on dynamic response characteristics of HSV has been analyzed in detail using the simulation model, and influence rules of various parameters on dynamic response characteristics have been established. Moreover, the correlation between interaction factors of main influence factors and dynamic response characteristics of HSV has also been analyzed. It is concluded that residual air gap, maximum lift of the valve stem, and spring pretightening force are the main influencing factors on dynamic response characteristics of HSV, and there are obvious interaction effects between them; when two or three of these main influencing factors are adjusted at the same time, the interaction effects should be considered.


2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Wenhu Zhang ◽  
Sier Deng ◽  
Guoding Chen ◽  
Yongcun Cui

In this paper, the formulas of elastohydrodynamic traction coefficients of four Chinese aviation lubricating oils, namely, 4109, 4106, 4050, and 4010, were obtained by a great number of elastohydrodynamic traction tests. The nonlinear dynamics differential equations of high-speed cylindrical roller bearing were built on the basis of dynamic theory of rolling bearings and solved by Hilber–Hughes–Taylor (HHT) integer algorithm with variable step. The influence of lubricant traction coefficient on cage's nonlinear dynamic behavior was investigated, and Poincaré map was used to analyze the influence of four types of aviation lubricating oils on the nonlinear dynamic response of cage's mass center. The period of nonlinear dynamic response of cage's mass center was used to assess cage's stability. The results of this paper provide the theoretical basis for selection of aviation lubricating oil.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lin Li ◽  
Xiaodan Guo ◽  
Zuyin Zou ◽  
Zhanyuan Zhu ◽  
Zihong Guo ◽  
...  

The structural damage of the lining structure at the entrance of a tunnel is the most common instability problem. The instability problem may cause dynamic effects such as earthquakes and blasting. Based on the seismic damage data collected from previous major earthquakes at the entrance of shallow-buried tunnel, the shaking table test and numerical simulation are used to analyze dynamic response characteristics and damage evolution characteristics of the tunnel in the shallow-buried hole at 30°. The study revealed the stress characteristics of tunnel lining and the mechanism of structural damage under earthquake excitation. The research results show that the biased tunnel (30°) is susceptible to damage on the unsymmetrical loading side, the biased ground surface leads to acceleration, and high speed also significantly increases the effect. The biased side leg of the tunnel lining cross section is a location with a large internal force distribution. The biased tunnel has a relatively unfavorable internal force value distribution and a larger peak, and the peak at the larger bias side has the largest peak value. The skewback and spandrel portion of the biased tunnel lining load are more likely to be damaged.


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