A New Method and Automatic Generation for Dynamic Analysis of Complex Planar Mechanisms Based on the Ordered Single-Opened-Chains

Author(s):  
Jian-Qing Zhang ◽  
Ting-Li Yang

Abstract This work presents a new method for kinetostatic analysis and dynamic analysis of complex planar mechanisms, i.e. the ordered single-opened-chains method. This method makes use of the ordered single-opened chains (in short, SOC,) along with the properties of SOC, and the network constraints relationship between SOC,. By this method, any planar complex mechanism can be automatically decomposed into a series of the ordered single-opened chains and the optimal structural decomposition route (s) can be automatically selected for dynamic analysis, the paper present the dynamic equation which can be used to solve both the kinetostatic problem and the general dynamic problem. The main advantage of the proposed approach is the possibility to reduce the number of equations to be solved simultaneously to the minimum, and its high automation as well. The other advantage is the simplification of the determination of the coefficients in the equations, and thus it maybe result in a much less time-consuming algorthem. The proposed approach is illustrated with three examples. The presented method can be easily extended to the dynamic analysis of spatial mechanisms.

Author(s):  
Hui-Ping Shen ◽  
Ting-Li Yang

Abstract This work presents a new method for kinematic analysis of planar complex mechanisms, i. e, the ordered single-opened-chains method. This method makes use of the ordered single-opened chains (in short, SOC.) along with the properities of SOC, and the network constraints relationship between SOC. By this method, any planar complex mechanism ran be automatically decomposed into a series of the ordered single-opened chains and the optimal structural decomposition route(s) can be automatically selected for kinematic analysis. The kinematic analysis equations with fewest unknown variables can be automatically generated and easily solved. Perhaps, the most attractive features of this method are its high automation and convergence in computer implementations. This work firstly describes the principle of the ordered SOC method and then introduces the computer automatic generation of this method along with the application to two complex linkages. The method developed can be easily extended to the kinemetic analysis of the spatial mechanisms.


Author(s):  
Song-Qing Shan ◽  
Ting-Li Yang

Abstract This paper presents a new method for kinematic error analysis of planar complex mechanisms, i.e., the ordered single -opened -chains method. This approach is based on the ordered single-opened chains (namely, series binary links, in short, SOCs)and makes use of the properties of SOCs and the network constraint relationships between SOCs. Its mathematical model harmonizes with the structure, kinematics, and dynamics model of mechanisms. The kinematic error analysis equations with few unknown variables can be automatically generated and easily solved. Therefore, any planar complex mechanism can be automatically decomposed into a series of the ordered single-opened-chains and then its kinematic error analysis can be easily completed through this method. Perhaps, the most attractive features of this method are its high automation and convergence in computer implementations. This work describes the principle of the ordered SOC method, introduces its computer automatic generation and compiles the corresponding computer program KEAPL. Two Examples are given at the end of the paper. The proposed method can be easily extended to the kinematic error analysis of the spatial mechanisms.


1907 ◽  
Vol 27 ◽  
pp. 264-268 ◽  
Author(s):  
Thomas Oliver

The determination of the degree of twist in a folded or ply thread composed of two or more strands is an easy matter. It is merely necessary to stretch the thread between two clamps, one being fixed and the other forming the end of a bar which can be rotated about its axis. A counter is attached to indicate the number of rotations. Rotating the thread in the opposite direction to its twist ultimately brings the singles parallel to each other. This point is easily observed. If we apply this method to single yarns we are at once confronted with the difficulty that the fibres constituting the yarn cannot be reduced to exact parallelism with each other.


1990 ◽  
Vol 192 ◽  
Author(s):  
G. Amato ◽  
L. Boarino ◽  
F. Fizzotti ◽  
C. Manfredotti

ABSTRACTWe propose to apply a new method to model the optical response of amorphous silicon thin films. This method presents the advantage of having a good physical insight. On the other hand, although the model has been originally tested on different materials like a-Si, a-Ge and a-GaAs, we show that it is also sensitive to small differences like those that can exist between intrinsic and doped a-Si:H.


Geophysics ◽  
1948 ◽  
Vol 13 (1) ◽  
pp. 92-97
Author(s):  
Sulhi Yüngül

In two papers published in Geophysics, one in the October, 1944, issue and the other in October, 1946, a system and method of calculation, called “Resistolog” method, was presented. The object of the Resistolog method is to eliminate the effects of superficial inhomogeneities which are the most troublesome obstacles in interpreting electrical sounding results in exploring deep, horizontal discontinuities. The following is a discussion of the papers mentioned above, mainly of the subject of (1) the apparent‐resistivity formula derived for use with the Resistolog configuration, (2) determination of inflectional points on apparent resistivity curves, (3) depth of penetration, and (4) distortion caused by the “far electrode.” A new method to determine inflectional points is also given. This paper includes a comprehensive knowledge about the forementioned papers and the reader may not have to refer to them.


2021 ◽  
Vol 1199 (1) ◽  
pp. 012076
Author(s):  
J Vavro ◽  
J Vavro ◽  
L Marček ◽  
M Taraba ◽  
L Klimek

Abstract This paper presents a kinematic and dynamic analysis and distribution of the stress for seven-item planar mechanism by means of the SolidWorks software. The authors of the introduced paper deal with the kinematic analysis of planar mechanisms as well as with the implementation of the vector method into the SolidWorks software program in order to determine the kinematic variables (quantities) of the individual bodies in the whole complex system. The dynamic analysis is performed on the basis of the kinematic analysis. Dynamic analysis allows us to design a system of bodies correctly and it is with the respect to the dynamic loading. For the interpretation of the introduced analysis, the seven-item planar mechanism was selected. Graphic dependence of kinematic and dynamic magnitudes of some points is given in dependence on the angle of rotation of the driving item and in dependence on time. In relation to the kinematic and dynamic analysis and subsequent simulation of the planar as well as spatial mechanisms, it is perfect solution to use SolidWorks software program. The considerable advantage of this mentioned program is based on its simplicity from the aspect of modeling and moreover, it is important to point out that utilisation of the mentioned program leads to results which are precise and accurate in the case of the numerical solution of the equations in the whole magnitude referring to motion of mechanism while the given results are obtained in the graphic form.


2005 ◽  
Vol 85 (6) ◽  
pp. 1441-1447 ◽  
Author(s):  
Nadine M. Johnston ◽  
David A. Ritz

The phenomenon of adoption, i.e. replacement of larvae prematurely liberated from the brood pouch of conspecifics, and kin recognition was examined in three mysid species found commonly in Tasmanian waters: Anisomysis mixta australis, Paramesopodopsis rufa and Tenagomysis tasmaniae. A new method for testing the incidence of adoption using fluoroscein dye, which enables the determination of ‘same stage’ adoptions, is described. Under field and laboratory conditions, all species practised intraspecific adoption into their own brood pouches. Under laboratory conditions the incidence of adoption was higher in T. tasmaniae than it was in the other two species. Tenagomysis tasmaniae also adopted its own young in preference to those of a conspecific. Differences in the incidence of adoption between the three species suggests a higher degree of maternal care in T. tasmaniae than in either A. mixta australis or P. rufa and may be explained by differences in anatomy, habitat conditions and predation pressure.


Author(s):  
Chieng-Liang Lai ◽  
Wei-Hua Chieng ◽  
David A. Hoeltzel

Abstract Traditional Euler-Lagrange methods for the dynamic analysis of kinematic chains require repetitive calculation of the kinematic constraints. This becomes very inefficient as the number of joints (or kinematic constraints) increases. This paper presents a new approach for the dynamic analysis of constrained dynamic systems. The salient feature of this approach is the separation of the kinematic analysis from the dynamic analysis. Following this separation, the resulting dynamic system becomes instantaneously unconstrained. While the discussion is mainly oriented towards the analysis of planar mechanisms, the model can be readily extended to the analysis of spatial mechanisms. A methodology for computer-aided symbolic derivation of the dynamic equations based on this approach is presented, and a numerical example which demonstrates a significant reduction in computing time for the dynamic analysis of a planar mechanism, as compared with conventional solution approaches, is provided.


2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Ting-Li Yang ◽  
Anxin Liu ◽  
Huiping Shen ◽  
Lubin Hang ◽  
Qiaode Jeffery Ge

Based on the general degree-of-freedom (DOF) formula for spatial mechanisms proposed by the author in 2012, the early single open chain (SOC)-based composition principle for planar mechanisms is extended to general spatial mechanisms in this paper. First, three types of existing mechanism composition principle and their characteristics are briefly discussed. Then, the SOC-based composition principle for general spatial mechanisms is introduced. According to this composition principle, a spatial mechanism is first decomposed into Assur kinematic chains (AKCs) and an AKC is then further decomposed into a group of ordered SOCs. Kinematic (dynamic) analysis of a spatial mechanism can then be reduced to kinematic (dynamic) analysis of AKCs and finally to kinematic (dynamic) analysis of ordered SOCs. The general procedure for decomposing the mechanism into ordered SOCs and the general method for determining AKC(s) contained in the mechanism are also given. Mechanism's kinematic (dynamic) analysis can be reduced to the lowest dimension (number of unknowns) directly at the topological structure level using the SOC-based composition principle. The SOC-based composition principle provides a theoretical basis for the establishment of a unified SOC-based method for structure synthesis and kinematic (dynamic) analysis of general spatial mechanisms.


2021 ◽  
Vol 1199 (1) ◽  
pp. 012047
Author(s):  
J Vavro ◽  
J Vavro ◽  
L Marček ◽  
M Taraba ◽  
L Klimek

Abstract This paper presents a kinematic and dynamic analysis and distribution of the stress for six-item planar mechanism by means of the SolidWorks software. The main purpose of the investigation is connected with the kinematic analysis of planar mechanisms as well as with the implementation of the vector method into the SolidWorks software program in order to determine the kinematic variables of the individual bodies in the whole investigated system. The process of the dynamic analysis is based on the kinematic analysis. The dynamic analysis makes possible to design a system of bodies correctly and it is with the respect to the dynamic loading. For the interpretation of the introduced analysis, the six-item planar mechanism was used as example (representative). Graphic dependence of kinematic and dynamic magnitudes of some points is given in dependence on the angle of rotation of the driving item and in dependence on time. In relation to the kinematic and dynamic analysis and subsequent simulation of the planar as well as spatial mechanisms, it is great solution to use SolidWorks software program. The considerable advantage of this mentioned program is based on its simplicity from the aspect of modeling and moreover, it is important to point out that utilisation of the mentioned program leads to results which are precise and accurate in the case of the numerical solution of the equations in the whole magnitude referring to motion of mechanism while the given results are obtained in the graphic form.


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