Study on Nonlinear Characteristics of Spatial Spreading Mechanism with Multiple Clearance Joints

2019 ◽  
pp. 697-707
Author(s):  
Wenzhou Lin ◽  
Xupeng Wang ◽  
Xiaomin Ji ◽  
Chunqiang Zhang
Keyword(s):  
Nonlinear Characteristics ◽  
Clearance Joints ◽  
Spatial Spreading

scholarly journals Dynamic Response Analysis of Planar Multilink Mechanism considering Wear in Clearances

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Shuai Jiang ◽  
Xiulong Chen ◽  
Yu Deng
Keyword(s):  
Theoretical Basis ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Nonlinear Characteristics ◽  
Wear Prediction ◽  
Normal Contact ◽  
Normal Contact Force ◽  
Clearance Joints ◽  
Revolute Joints ◽  
Analysis Of Dynamics

Clearance wear is one of the factors that affects dynamics for mechanical systems. A numerical methodology suitable for modeling and calculation of wear at multiple revolute clearance pairs in the field of the planar multilink mechanism is proposed. In this paper, the 2-DOF nine-bar mechanism considering two revolute clearance joints is regarded as the study object. Normal contact force and friction force models of revolute clearance joints used Lankarani–Nikravesh (L-N) and LuGre models, respectively. The iterative wear prediction process based upon Archard’s model has been applied to calculate wear characteristics. The wear prediction procedure is integrated with multibody dynamics, wear depths at revolute clearance joints are calculated, and the surface of shaft and bearing is reconstructed twice. The dynamic responses of mechanism considering two nonregular revolute clearances caused by wear are studied in depth. The nonlinear characteristics of the mechanism after wear are studied by the phase diagram and Poincaré map. Influences of different initial constant clearance values and different driving speeds on wear of two revolute joints are also researched. The results show that it is necessary to consider the factor of irregular clearances caused by wear in analysis of dynamics of precision mechanisms. Initial constant clearance values and driving speeds have some influence on wear phenomenon. This research provides a theoretical basis for studying dynamics of the planar multilink mechanism considering wear in multiple clearances.

Laser Oscillation in Aggregates of Ultrasmall Si Nanoparticles

2002 ◽  
Vol 728 ◽  
Author(s):  
Munir H. Nayfeh
Keyword(s):  
Stimulated Emission ◽  
Gaussian Beams ◽  
Single Particles ◽  
Nonlinear Characteristics ◽  
Femtosecond Radiation ◽  
Highly Nonlinear ◽  
Line Narrowing ◽  
Si Nanoparticles ◽  
Speckle Patterns ◽  
Spectral Line Narrowing

AbstractWe dispersed electrochemically etched Si into ultrabright ultrasmall nanoparticles, with brightness higher than fluorescein or rhodamine. The emission from single particles is readily detectable. Aggregates or films of the particles exhibit emission with highly nonlinear characteristics. We observe directed blue beams at ∼ 410 nm between faces of aggregates excited by femtosecond radiation at 780 nm; and at ∼ 610 nm from aggregates of red luminescent Si nanoparticles excited by radiation at 550-570 nm from a mercury lamp. Intense directed Gaussian beams, a pumping threshold, spectral line narrowing, and speckle patterns manifest the emission. The results are analyzed in terms of population inversion and stimulated emission in quantum confinement-induced Si-Si dimer phase, found only on ultrasmall Si nanoparticles. This microlasing constitutes an important step towards the realization of a laser on a chip.

Nonlinear Characteristics of Periodically Fully Developed Dlow in Cross-Flow Tube Bundle

2014 ◽  
Author(s):  
Qingqing Yong ◽  
mo yang ◽  
Zhiyun Wang ◽  
Jian Chen ◽  
Dan Su ◽  
...  
Keyword(s):  
Tube Bundle ◽  
Cross Flow ◽  
Flow Tube ◽  
Nonlinear Characteristics

NICROBRAZ 160

Alloy Digest ◽  
1994 ◽  
Vol 43 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Clearance Joints

Abstract NICROBRAZ 160 is for wide clearance joints where heavier fillets or greater joint ductility and machinability are desired. This datasheet provides information on composition, physical properties, and hardness. It also includes information on corrosion resistance as well as joining. Filing Code: Ni-472. Producer or source: Wall Colmonoy Corporation.

Process simulation modeling of phytophagans' influence on the yield of seed fruit crops

2019 ◽  
pp. 138-143
Author(s):  
V. A. Shishkin ◽  
E. P. Rybalkin ◽  
E. B. Balykina
Keyword(s):  
Process Simulation ◽  
Simulation Modeling ◽  
Software Package ◽  
Development Process ◽  
Simulation Models ◽  
Vegetation Period ◽  
Fruit Crops ◽  
Generational Change ◽  
Apple Trees ◽  
Nonlinear Characteristics

Simulation modeling of phytophagans’ influence on the yield of seed fruit crops, in particular apple trees, was carried out. By means of simulation models the importance of phytophagans’ influence at different stages of the vegetation period and the period of fruit ripening was revealed. The software package Matlab was used to build simulation models. As a result, simulation models with nonlinear characteristics were obtained, which maximally reflected the studied processes. The developed models imitate the process of phytophagans’ development. Generation change of pests and all stages of their development are simulated. Their respective numbers are recorded at each stage for all generations. The development process at each stage is modeled by separate subsystems of the simulation model. To simulate the development of one generation of pests, these subsystems are connected by external links. In addition, part of the relationships provides a simulation of generational change. There are a number of input parameters that allow to configure the simulation of the process of changing generations, taking into account the peculiarities of the development of various phytophagans.

scholarly journals Dynamics of luffing motion of a hydraulically driven shell manipulator with revolute clearance joints

2021 ◽  
Author(s):  
Chen Zhi-qun ◽  
Qian Lin-fang ◽  
Chen Guang-song ◽  
Nie Shou-cheng ◽  
Yin Qiang ◽  
...  
Keyword(s):  
Clearance Joints
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