Systematic Analysis and Application of Multi-Loop Linkages with Multiple Joints in Modern Mechanical Engineering

2020 ◽  
pp. 11-25
Author(s):  
V.I. Pozhbelko ◽  
E.N. Kuts
Keyword(s):  
System Analysis ◽  
Load Capacity ◽  
Kinematic Chain ◽  
Algebraic Equations ◽  
Range Of Movement ◽  
Systematic Analysis ◽  
Modern Engineering ◽  
Topological Characteristics ◽  
High Load Capacity

This work analyzes various designs of multi-link linkage mechanisms with rotational kinematic pairs in the form of cylindrical joints of high load capacity that are widely used in various fields of technology. The use of multiple joints in such linkage mechanisms simplifies their design, reduces dimensions, weight and cost, as well as expands their functionality and the range of movement of the working body. The considered methodology of the system analysis of the structure and mobility of plane multi-loop linkage mechanisms with multiple joints includes the sequential determination of all the basic topological characteristics of the closed kinematic chain of a complex mechanism and its mobility in a given space of possible movements from a set of simple algebraic equations. The effectiveness of the proposed method for constructing reliable mechanisms with any given number and type of multi-loop joints is confirmed by the presented examples of the system analysis of the structure and mobility of plane multiple lever mechanisms used in various fields of modern engineering.

Modified joint connectivity approach for identification of topological characteristics of planar kinematic chains

2011 ◽  
Vol 225 (11) ◽  
pp. 2700-2717 ◽  
Author(s):  
G S Bedi ◽  
S Sanyal
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Kinematic Chains ◽  
Multiple Degrees Of Freedom ◽  
Preferred Frame ◽  
Topological Characteristics ◽  
Synthesis Stage ◽  
Different Levels ◽  
Selection Of

In a kinematic chain, the links are connected to each other through joints. The connectivity of a joint indicates the number of joints to which it is connected. The connectivity level of a joint indicates the distance by which it is separated from the adjacent joints. The concept of joint connectivity and its application to detect isomorphism among kinematic chains and their inversions has been already reported by authors. The method utilizes the connectivity of joints at different levels to detect isomorphism and inversions among planar kinematic chains. The method is applied to eight-, nine-, and ten-link planar kinematic chains. The results so obtained are in agreement with those available in the literature. In this study, the method is further improved by incorporating the type of joint to make it more effective for the detection of isomorphism and distinct inversions. A joint connectivity table completely representing the kinematic chain is proposed. The application of the method is extended for the determination of additional topological characteristics of chains such as categorization of kinematic chains and selection of preferred frame, input and output links for function and path generation. The concept of ‘Motion Transfer Ability’ is introduced and utilized to develop numerical measures for comparing and categorizing the chains at the synthesis stage of mechanism design for a specific application. The method was successfully tested on planar kinematic chains with single and multiple degrees of freedom and the results for eight- and nine-link kinematic chains are appended.

Vibro piles performance prediction using result of CPT

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Paweł Więcławski
Keyword(s):  
Load Capacity ◽  
Empirical Method ◽  
Load Test ◽  
Soil Parameters ◽  
Static Load Test ◽  
Additional Advantage ◽  
Limit Values ◽  
S Curve ◽  
High Load Capacity

Abstract Vibro piles belong to the group of full displacement piles with an expanded base, characterised by a very high load capacity, especially in non-cohesive soils. The problem is to adopt a reliable method for the determination of full load–settlement (Q–s) curve. A frequent difficulty is the determination of the load capacity limit based on the static load test because the course of the load–settlement curve is of a linear nature. This publication presents the empirical method. It allows direct prediction of a full axially loaded pile settlement curve based on the values of qc cone resistance obtained in cone penetration test (CPT). The advantage offered by this procedure is the accuracy of the obtained limit values in relation to the actual load-bearing capacity as compared to other methods based on soil parameters obtained in in situ testing. An additional advantage is the Q–s characteristics, which enable designing for intermediate values, allowing for the criterion of minimal or equal settlements. The shape of analytical curves was compared with static pile load test (SPLT) curves. This comparison showed large convergences between the analytical and measured curves.

scholarly journals Peculiarities of Representation in Civil Proceedings

2019 ◽  
Vol 85 (2) ◽  
pp. 44-55
Author(s):  
K. R. Rezvorovych
Keyword(s):  
System Analysis ◽  
Civil Procedure ◽  
Practical Significance ◽  
Systematic Analysis ◽  
Legal Personality ◽  
Civil Process ◽  
Procedure Code ◽  
Civil Proceedings ◽  
The Subject

The thesis was devoted to the research of the peculiarities of representation in the civil process. The main objective of this thesis is the determination of the peculiarities of legal adjusting for the representation in the civil process. Methodological basis of the thesis consisted of such methods as: formal-logical, system analysis, dialectical and hermeneutical. The relevance of this thesis is evidenced in particular by there that was disclosed such facts as: the content of the institute of representation in civil law and civil process doctrine; the circle of persons who can be representatives in civil procedure. It was made a systematic analysis of the provisions of the Civil Procedure Code (CPC) of Ukraine on the subject of the implementation of the representation of individuals in civil proceedings. There were investigated the problems of restricting the circle of persons who can be representatives in civil proceedings. The analysis of standing and its confirmation by various persons who can carry out representation in civil proceedings was done. According to the results of the research, it was established that modern CPC of Ukraine does not determine the essence of relations between representatives and persons whose interests they realize. The mainstreaming and law-governing influence is mainly related to the legal personality of the representatives, their procedural status. It was also determined the range of duties and rights of representatives within the civil legal process. In addition, it was proved that the modern CPC of Ukraine is being introduced in the state, in fact, a monopoly on the representation of the parties by a lawyer in the courts, in the civil process, but leaves the possibility of realizing the relations of representation between an individual and another person who does not have the lawyer status, who ruled only in, such cold as, minor affairs. Thus, the practical significance of the conclusions reached was aimed primarily at the theoretical and methodological plane to continue the reform of the institution of representation in the civil process, as well as in the practical activities of representatives in the context of expanding the opportunities for individuals to exercise their procedure’s rights.

MODELING OF NONLINEAR VIBRATION PROBLEMS WITH FLUID FLOWS THROUGH PIPELINES

2018 ◽  
pp. 44-47
Author(s):  
F.J. Тurayev
Keyword(s):  
Differential Equations ◽  
Nonlinear Vibration ◽  
Viscoelastic Properties ◽  
Construction Material ◽  
Fluid Flows ◽  
Variable Coefficients ◽  
Algebraic Equations ◽  
Flowing Liquid ◽  
Vibration Problems

In this paper, mathematical model of nonlinear vibration problems with fluid flows through pipelines have been developed. Using the Bubnov–Galerkin method for the boundary conditions, the resulting nonlinear integro-differential equations with partial derivatives are reduced to solving systems of nonlinear ordinary integro-differential equations with both constant and variable coefficients as functions of time.A system of algebraic equations is obtained according to numerical method for the unknowns. The influence of the singularity of heredity kernels on the vibrations of structures possessing viscoelastic properties is numerically investigated.It was found that the determination of the effect of viscoelastic properties of the construction material on vibrations of the pipeline with a flowing liquid requires applying weakly singular hereditary kernels with an Abel type singularity.

Markov Jump Linear System Analysis of a Microgrid Operating in Islanded and Grid Tied Modes

2020 ◽  
Author(s):  
Gilles Mpembele ◽  
Jonathan Kimball
Keyword(s):  
Monte Carlo ◽  
Power Systems ◽  
Power System ◽  
System Analysis ◽  
Differential Algebraic Equations ◽  
Algebraic Equations ◽  
Markov Jump ◽  
Numerical Application ◽  
Conditional Moments ◽  
Markov Jump Linear Systems

<div>The analysis of power system dynamics is usually conducted using traditional models based on the standard nonlinear differential algebraic equations (DAEs). In general, solutions to these equations can be obtained using numerical methods such as the Monte Carlo simulations. The use of methods based on the Stochastic Hybrid System (SHS) framework for power systems subject to stochastic behavior is relatively new. These methods have been successfully applied to power systems subjected to</div><div>stochastic inputs. This study discusses a class of SHSs referred to as Markov Jump Linear Systems (MJLSs), in which the entire dynamic system is jumping between distinct operating points, with different local small-signal dynamics. The numerical application is based on the analysis of the IEEE 37-bus power system switching between grid-tied and standalone operating modes. The Ordinary Differential Equations (ODEs) representing the evolution of the conditional moments are derived and a matrix representation of the system is developed. Results are compared to the averaged Monte Carlo simulation. The MJLS approach was found to have a key advantage of being far less computational expensive.</div>

Measuring Mobility of the Metacarpophalangeal Joints II, III, IV, and V in the Dorso-Volar Plane

1984 ◽  
Vol 13 (1) ◽  
pp. 15-20 ◽  
Author(s):  
C Wagner ◽  
D Drescher
Keyword(s):  
Healthy Subjects ◽  
Reliability And Validity ◽  
Repeated Measurements ◽  
Interrater Agreement ◽  
Range Of Movement ◽  
Men And Women ◽  
Examination Method ◽  
Total Range ◽  
Flexion And Extension

An electronic gravity goniometer was developed for determining the passive range of movement of the MCP joints II, III, IV, and V in the dorso-volar plane by the use of preset torques. Test–retest measurements on 23 healthy subjects between the ages of 18 and 57 demonstrated high intrarater and interrater agreement for determining the total range. In the determination of the amounts of flexion and extension the measurement of the flexion was less reliable. There was overall evidence of a declining tendency of reliability from MCP joint II to MCP joint V, probably caused by different reactions of the joints to repeated measurements. The higher total range of the MCP joints in women was principally caused by a higher range of extension. In the case of men and women the range of MCP joint V was noticeably greater than that of the other three joints. The mobility of the four MCP joints correlates relatively closely as a whole, however, in the case of the non-adjacent joints less closely than with the adjacent joints. Reliability and validity of the examination method were balanced against one another with regard to testing of the biomechanical pre-conditions for manual dexterity.

Experimental analysis of the automated process of sanding aircraft surfaces

2014 ◽  
Vol 118 (1199) ◽  
pp. 53-64
Author(s):  
B. Giublin ◽  
J. A. Vieira ◽  
T. G. Vieira ◽  
L. G. Trabasso ◽  
C. A. Martins
Keyword(s):  
Load Capacity ◽  
Manufacturing Processes ◽  
Robotic Cell ◽  
Research Project ◽  
Average Value ◽  
Aluminum Metal ◽  
Structural Assembly ◽  
Riveting Process ◽  
High Load Capacity ◽  
Operating Method

Abstract ITA and EMBRAER are currently executing the research project Automation of Aircraft Structural Assembly (AASA) whose goal is to implement a robotic cell for automating the riveting process of aeronautical structures. The proposal described herein complements the AASA project, adds other manufacturing processes, namely sanding and polishing of aircraft surfaces. To implement the additional processes AASA project resources and facilities were used (robots and metrology systems) and devices designed and /or acquired to allow sharing of these resources. Among these, an Automatic Tooling Support for AERonautics structures (ATS_AER) was designed and built; also, a robot tool changer with high load capacity was acquired. The outcome of this research project is the evaluation of the feasibility of automating the processes of sanding and polishing metal surfaces in the aircraft manufacture using robots. The operating method adopted for surface treatment employed the ‘U’ type trajectory optimised to be run by a KUKA robot KR 500. The sanding process has been applied to aluminum metal sheet specimen sized 2•18ft2 (0•20m2) and used commercial 600 and 800 sandpaper. The automated sanding process yielded an average value of RA 0•48 ± 0•08 which is 25% more efficient when compared to the traditional, manual process whose average value of RA is 0•75 ± 0•51.

Static Performance of a Hydrostatic Thrust Foil Bearing for Large Scale Oil-Free Turbomachines

2020 ◽  
Author(s):  
Nguyen LaTray ◽  
Daejong Kim ◽  
Myongsok Song
Keyword(s):  
Large Scale ◽  
Load Capacity ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Outer Diameter ◽  
Frictional Loss ◽  
Foil Bearing ◽  
Foundation Model ◽  
Static Performance ◽  
High Load Capacity

Abstract This work presents a novel design of a hydrostatic thrust foil bearing (HSTFB) with an outer diameter of 154mm along with simulation and test results up to specific load capacity of 223kPa (32.3psi). The HSTFB incorporates a high pressure air/gas injection to the thrust foil bearing with a uniform clearance. This bearing has high load capacity, low power loss, and no friction/wear during startup and shutdown. In addition, the HSTFB allows for bidirectional operation. The paper also presents an advanced simulation model which adopts the exact locations of a tangentially arranged bumps to a cylindrical two-dimensional plate model of the top foil. This method predicts top foil deflection with better accuracy than the traditional independent elastic foundation model which distributes the bump locations over the nodal points in the cylindrical coordinates, and with less computational resource than the finite element method applied to the entire bump/top foils. The presented HSTFB, was designed for Organic Rankine Cycle (ORC) generators, but its performance was predicted and measured using air in this paper. The bearing static performance is compared analytically against the rigid counterpart, and presented at different supply pressures, speeds, and minimum film thicknesses. Experimental verification is conducted at 10, 15 and 20krpm. The measured load capacity and frictional loss agree well with the prediction. The measured film thickness also agrees with the prediction after the structural deflection of the thrust runner disc is compensated. Overall, the novel HSTFB demonstrates an excellent static performance and shows good potential for adoption to the intended ORC generators and other large oil-free turbomachines.

Current State of Legislation, Law Enforcement and Judicial Practice in the Sphere of Conclusion, Modification and Termination of Lease Agreements for Land Plots, Concluded for Construction Purposes

2020 ◽  
Vol 1 ◽  
pp. 16-23
Author(s):  
V. V. Cheremukhin ◽  
Keyword(s):  
Law Enforcement ◽  
System Analysis ◽  
Legal Regulation ◽  
Scientific Development ◽  
Synthesis System ◽  
Judicial Practice ◽  
Current State ◽  
General Scientific ◽  
Statistical Indicators

Construction, as a sphere of the national economy, has impressive statistical indicators, determining the importance and relevance of its proper legal regulation, especially in terms of land use for relevant purposes. This article discusses the current situation in the sphere of provision of land plots for construction purposes, further alteration and termination of the relevant lease relations; provides a detailed analysis of the current legislation, law enforcement and judicial practice in such sphere. The purpose of the article is to analyze and summarize legislation judicial and law enforcement practice in this area, as well as the development of specific directions for a comprehensive dissertation research, proposals for improving the legislation regulating these relations. This goal is achieved by solving tasks such as studying of the existing legal regulation of disputed legal relations, law enforcement and judicial practice, identification of problematic and conflict-of-laws issues in the field under consideration, review of the degree of scientific development of the research topic, determination of trends in the development of this sphere of legal relations, development of specific proposals for changing legislation and law enforcement practice. General scientific (synthesis, system analysis, analogy) and special (formal-legal, comparative-legal) methods are used to solve the above problems. Based on the results of consideration of these issues, the author formulates the main problems of the legal relations under consideration, an assessment of the current degree of scientific development of this field is given, the main directions of the planned scientific research are also outlined, proposals are formulated to improve legislation and law enforcement practice.

scholarly journals Determination of parameters for Cauchy’s problem for systems of ODEs with application to biological modelling

BIOMATH ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 1604231
Author(s):  
A.N. Pete ◽  
Peter Mathye ◽  
Igor Fedotov ◽  
Michael Shatalov
Keyword(s):  
Experimental Data ◽  
Mathematical Models ◽  
Least Squares ◽  
Numerical Method ◽  
Least Squares Method ◽  
Algebraic Equations ◽  
Systems Of Odes ◽  
Determination Of Parameters ◽  
Biological Modelling

An inverse numerical method that estimate parameters of dynamic mathematical models given some information about unknown trajectories at some time is applied to examples taken from Biology and Ecology. The method consisting of determining an over-determined system of algebraic equations using experimental data. The solution of the over-determined system is then obtained using, for example the least-squares method. To illustrate the effectiveness of the method an analysis of examples and corresponding numerical example are presented.

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