A Digraph Approach to System Wear Evaluation and Analysis

1994 ◽  
Vol 116 (2) ◽  
pp. 268-274 ◽  
Author(s):  
O. P. Gandhi ◽  
V. P. Agrawal
Keyword(s):  
System Structure ◽  
Component Level ◽  
Matrix Methods ◽  
Wear Process ◽  
Analysis And Evaluation ◽  
Wear Analysis ◽  
Optimum Selection ◽  
Step Procedure ◽  
Wear Evaluation ◽  
Selection Of

System structure is important for analyzing wear of a system. In this paper, this aspect is considered at the component level and is modeled using digraph and matrix methods. Contributing wear factors and the degree of influence among these factors, which determine wear independence and wear process between mating components, are identified. This along with the wear measure of subsystems determines the system wear. The procedure develops wear functions for characterization and comparison of subsystems of different types. These are also useful for wear analysis and evaluation leading to an optimum selection of subsystems based on the wear. The procedure is also shown to be useful at the operating state of a system and subsystems. Step-by-step procedure for system wear evaluation is presented. Methodology is also demonstrated by an example.

scholarly journals Optimum Selection of Variable Pitch for Chatter Suppression in Face Milling Operations

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 112 ◽  
Author(s):  
Alex Iglesias ◽  
Zoltan Dombovari ◽  
German Gonzalez ◽  
Jokin Munoa ◽  
Gabor Stepan
Keyword(s):  
Removal Rate ◽  
Face Milling ◽  
Heavy Duty ◽  
Variable Pitch ◽  
Thin Walls ◽  
Chatter Suppression ◽  
Milling Operations ◽  
Optimum Selection ◽  
Cutting Capacity ◽  
Selection Of

Cutting capacity can be seriously limited in heavy duty face milling processes due to self-excited structural vibrations. Special geometry tools and, specifically, variable pitch milling tools have been extensively used in aeronautic applications with the purpose of removing these detrimental chatter vibrations, where high frequency chatter related to slender tools or thin walls limits productivity. However, the application of this technique in heavy duty face milling operations has not been thoroughly explored. In this paper, a method for the definition of the optimum angles between inserts is presented, based on the optimum pitch angle and the stabilizability diagrams. These diagrams are obtained through the brute force (BF) iterative method, which basically consists of an iterative maximization of the stability by using the semidiscretization method. From the observed results, hints for the selection of the optimum pitch pattern and the optimum values of the angles between inserts are presented. A practical application is implemented and the cutting performance when using an optimized variable pitch tool is assessed. It is concluded that with an optimum selection of the pitch, the material removal rate can be improved up to three times. Finally, the existence of two more different stability lobe families related to the saddle-node and flip type stability losses is demonstrated.

scholarly journals METHOD FOR IDENTIFYING SUITABLE COMPONENTS FOR FUNCTIONAL INTEGRATION – FOCUSING ON GEOMETRIC CHARACTERISTICS

2021 ◽  
Vol 1 ◽  
pp. 2047-2056
Author(s):  
Michael P. Voigt ◽  
Dominik Klaiber ◽  
Patrick Hommel ◽  
Daniel Roth ◽  
Hansgeorg Binz ◽  
...  
Keyword(s):  
Lightweight Design ◽  
Functional Integration ◽  
Resource Efficiency ◽  
Installation Space ◽  
Geometric Properties ◽  
Geometric Characteristics ◽  
Step Procedure ◽  
Cad Models ◽  
Selection Of

AbstractThe approach of functional integration has the potential to solve challenges regarding lightweight design and resource efficiency since the number of parts and therefore the weight and needed installation space can be reduced. One important step in developing integrative concepts is the pre-selection of suitable functions or components. Previous methods of pre-selection take various aspects into account. However, pre-selection based on these methods usually requires additional tables and forms, whose preparation and editing quickly becomes time-consuming. At the same time, most of the development engineers are working on CAD models. However, their use in the selection of suitable integration partners is not yet supported sufficiently. The development of more than 80 concepts on five different vehicles has shown that the consideration of geometric properties (position, orientation, size) is effective, as they can be identified with minimal analysis effort while working on CAD. In this paper a four-step procedure is presented how integration partners can be identified directly on the basis of CAD models. A following evaluation with development engineers in practice completes the research.

scholarly journals Obsidian from the Neolithic Layers of “Grotta di San Michele Arcangelo di Saracena” (Cosenza), Italy. A Preliminary Report

2021 ◽  
Vol 7 (1) ◽  
pp. 615-630
Author(s):  
Vincenza Forgia ◽  
Robert H. Tykot ◽  
Andrea Vianello ◽  
Elena Natali
Keyword(s):  
Preliminary Report ◽  
Second Phase ◽  
Early Neolithic ◽  
Late Neolithic ◽  
Resources Management ◽  
Lithic Assemblage ◽  
Wear Analysis ◽  
Selection Of ◽  
Preliminary Selection

Abstract The paper presents the results obtained by techno-typological analysis of a lithic assemblage from the Neolithic layers of Grotta San Michele Arcangelo di Saracena (Cosenza) together with the results of micro-wear analysis obtained from a preliminary selection of obsidian artifacts with different provenances distinguished by pXRF analysis. The site provides one of the best preserved Neolithic sequences in the area, from the earliest Impressed Wares (or Impresse Arcaiche) (early sixth millennium BC) to the Spatarella pottery style (end fifth – early fourth millennium BC). Along the Neolithic sequence, it is possible to observe some major changes within lithic resources management. In particular, it is possible to notice some techno-typological breakages between the Early Neolithic and the further stages, until the second phase of the Late Neolithic, when another rupture, corresponding to the Spatarella facies, is evident.

Design of LQR based PI controller with optimum selection of weights for Time Delay Process

2021 ◽  
Author(s):  
K Harshavardhana Reddy ◽  
Sachin Sharma ◽  
B. Madhuri ◽  
K Shivarama Krishna
Keyword(s):  
Time Delay ◽  
Pi Controller ◽  
Optimum Selection ◽  
Selection Of

scholarly journals Optimum Selection of Wind Turbines Using Normalized Power and Capacity Factor Curves

2021 ◽  
pp. 2813-2823
Author(s):  
Firas A. Hadi ◽  
Zaid F. Makki ◽  
Rafa A. Al-Baldawi
Keyword(s):  
Wind Turbine ◽  
Performance Index ◽  
Shape Parameter ◽  
Parameters Estimation ◽  
Capacity Factor ◽  
Turbine Performance ◽  
Optimum Selection ◽  
Novel Method ◽  
A Site ◽  
Selection Of

The main objective of this paper is present a novel method to choice a certain wind turbine for a specific site by using normalized power and capacity factor curves. The site matching is based on identifying the optimum turbine rotation speed parameters from turbine performance index (TPI) curve, which is obtained from the higher values of normalized power and capacity factor curves. Wind Turbine Performance Index a new ranking parameter, is defined to optimally match turbines to wind site. The relations (plots) of normalized power, capacity factor, and turbine performance index versus normalized rated wind speed are drawn for a known value of Weibull shape parameter of a site, thus a superior method is used for Weibull parameters estimation which is called Equivalent Energy Method (EEM).

scholarly journals The Nature of Compounding

2021 ◽  
Vol 2 (1) ◽  
pp. 01-21
Author(s):  
Pius ten Hacken
Keyword(s):  
Second Step ◽  
Linguistic Terms ◽  
Scientific Terminology ◽  
Step Procedure ◽  
To Come ◽  
Universal Definition ◽  
Definition Of ◽  
Selection Of

This paper addresses the question of the definition of compounding from a terminological perspective. In terminology, concepts are defined by a selection of properties shared by prototypical cases. For scientific terminology, the selection is validated by the strength of the theories that can use the definition. It is shown that morphophonological criteria often adduced in the delimitation of compounding are not adequate in a universal definition. In order to come up with a better definition, a two-step procedure is proposed. In the first step, a universal definition is used to determine for constructions in a particular language whether they belong to compounding. In the second step, language-specific properties are used to identify instances of these constructions. A definition is proposed that takes a compound as a word with a binary, headed structure, a relation between the elements that is not determined by compounding and a non-head that is not introduced as an entity in the discourse. The use of this definition is illustrated with a number of constructions in different languages. It is shown that expressions commonly called exocentric and copulative compounds are generally not compounds in this definition, but that some expressions that have been labelled as such are in fact compounds. The two-step procedure demonstrated here for compounding can also be used for other linguistic terms.

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