The Assembly Variation Modeling for the Rear Casing Wax Part Based on Polar Coordinate

2015 ◽  
Author(s):  
Changhui Liu ◽  
Sun Jin ◽  
Xinmin Lai ◽  
Jie Luo ◽  
Bo He ◽  
...  
Keyword(s):  
Variation Analysis ◽  
Practical Application ◽  
Coordinate Systems ◽  
Computational Accuracy ◽  
Dimensional Precision ◽  
Shaped Part ◽  
Polar Coordinate ◽  
Cartesian Coordinate ◽  
Assembly Variation Modeling

Rear casing is a key part of the aeroplane engine. Its dimensional precision is significant to the quality of the aeroplane engine. In the rear casing manufacturing process, the assembly variation of its corresponding wax dramatically affects the final dimensions. In this paper, a polar-coordinate based model is proposed to calculate the assembly variation of ring-shaped rear casing wax part. It avoids the variation caused by the coupling relationship between Cartesian coordinate systems and locating position. We also compare the polar-coordinate based model with the ordinary one in practical application. The results show that the polar-coordinate based model can simplify the calculating process and improve the computational accuracy for the assembly variation analysis of the ring-shaped part.

Variation Analysis for Composite Parts With Considering Local Delamination Defects

2019 ◽  
Author(s):  
Jinyu Liu ◽  
Zhimin Li ◽  
Tao Liu ◽  
Xinxin Li
Keyword(s):  
Composite Structures ◽  
Laminate Composite ◽  
Accurate Solution ◽  
Structural Performance ◽  
Beam Model ◽  
Variation Analysis ◽  
Dimensional Precision ◽  
Influence Coefficients ◽  
Assembly Precision

Abstract Laminate composite components have been widely used in engineering fields, such as aerospace and aircraft fields, automotive industries, marine and civil engineering. Due to inherent properties of laminated composites, the effects of local delamination defects will result in a decrease of assembly dimensional precision and mechanical property, and a variation analysis considering the effect of delamination defects become increasingly indispensable. In order to understand the influence relationship between delamination defects and manufacturing deviations, a methodology based on the method of influence coefficients is proposed to analyze the influence relationship between delamination defects and manufacturing deviations. Then, local delamination modes are developed based on the interface deformable bi-layer beam model with consideration of transverse shear and delamination tip deformations. This model provides an accurate solution with the delaminated composite structures. Finally, the effect of local delamination length ratio (a/h) has been further studied for the assembly precision analysis based on the flexible joint model, and the comparison of simulation result shows that the delamination has a signification influence on the structural performance and the quality of the product.

Spatial and Temporal variation analysis of water quality of Hemavathi River, Karnataka, India

2018 ◽  
Vol 6 (9) ◽  
pp. 196
Author(s):  
Santhosh K. M ◽  
S. Prashanth
Keyword(s):  
Water Quality ◽  
Agricultural Runoff ◽  
Spatial And Temporal Variation ◽  
Final Conclusion ◽  
Variation Analysis ◽  
Pollution Load ◽  
Quality Of Water ◽  
Pollution Loading ◽  
Origin Point

Urban development, agricultural runoff and industrialization have contributed pollution loading on the environment.  In this study Hemavathi river water from a stretch from its origin point to its sangama was studied for pollution load by determining parameters of water quality like pH, Alkalinity,  Ca, Mg, Nitrate, TDS, BOD, COD , and the results were compared with WHO and BIS standards to draw final conclusion on the quality of water.

scholarly journals Ten Basic Rules of Antibody Validation

2018 ◽  
Vol 13 ◽  
pp. 117739011875746 ◽  
Author(s):  
Michael G Weller
Keyword(s):  
Practical Application ◽  
Validation Criteria ◽  
Antibody Validation ◽  
Quality Of Research

The quality of research antibodies is an issue for decades. Although several papers have been published to improve the situation, their impact seems to be limited. This publication makes the effort to simplify the description of validation criteria in a way that the occasional antibody user is able to assess the validation level of an immunochemical reagent. A simple, 1-page checklist is supplied for the practical application of these criteria.

Chemical Structure of Vulcanized Rubber

1939 ◽  
Vol 12 (1) ◽  
pp. 43-55
Author(s):  
J. R. Brown ◽  
E. A. Hauser
Keyword(s):  
Chemical Structure ◽  
Empirical Knowledge ◽  
Extensive Investigation ◽  
Practical Application ◽  
True Nature ◽  
Rubber Industry ◽  
Vulcanized Rubber ◽  
Metallic Salts ◽  
Other Substances

Abstract A CENTURY ago, Charles Goodyear in America and Th. Hancock in England found that the properties of crude rubber could be greatly improved by heating it with sulfur. The product resulting was more elastic, more resistant to tear and abrasion, less affected by solvents, and decidedly less thermoplastic. The treatment of rubber to give these desired properties is known generally as vulcanization and must be considered as the basis for the enormous growth of the rubber industry and the extensive use of rubber products in our everyday life. Broadly speaking, vulcanization involves the reaction, in some fashion, of sulfur with rubber. Extensive investigation has revealed other substances, such as benzoyl peroxide or polynitrobenzenes, which can transform rubber into a “vulcanized” condition. Experience has also shown that metallic salts of zinc or lead and especially certain organic compounds called “accelerators” greatly affect the rate of vulcanization, and these are favorably employed in practice. A vast amount of empirical knowledge has been gained which has greatly improved the practical application of vulcanization and the quality of rubber products, but which has failed as yet to reveal a complete picture of the true nature of the process.

scholarly journals COMPARISON OF BASIC MAINTENANCE CONCEPTS USING WITNESS

2021 ◽  
Vol 2021 (6) ◽  
pp. 5435-5440
Author(s):  
VLADIMIRA SCHINDLEROVA ◽  
◽  
IVANA SAJDLEROVA ◽  
Keyword(s):  
21St Century ◽  
Simulation Software ◽  
Predictive Maintenance ◽  
Maintenance Management ◽  
Practical Application ◽  
Manufactured Products ◽  
The Right ◽  
Positive Effect ◽  
Production Facilities

Maintenance is a complex, extensive and important issue in terms of its impact on the quality of manufactured products or services provided in all areas of industry. The importance of predictive maintenance for the industry in the 21st century is crucial. However, the right approach to maintenance management is often underestimated in many companies today, although it can have a very positive effect on the company’s efficiency. Using the example of a practical application, the paper includes a comparison of three main maintenance concepts – classical (reactive), planned, predictive through the simulation software Witness. Maintenance concepts are compared in terms of their ability to solve and eliminate failures that occur in production facilities during operation.

scholarly journals Percepcja i projekcja krajobrazu: teorie, zastosowania, oczekiwania = Perception and projection of the landscape: theories, applications, expectations

2019 ◽  
Vol 91 (3) ◽  
pp. 365-384
Author(s):  
Tadeusz Jan Chmielewski ◽  
Szymon Chmielewski ◽  
Agnieszka Kułak
Keyword(s):  
Scientific Work ◽  
Research Field ◽  
Practical Application ◽  
Landscape Perception ◽  
Knowledge Based ◽  
Space Projection ◽  
Surrounding Space ◽  
New Research ◽  
Opening Up

The human species transforms the landscape to meet its needs, but landscape resources and valuable features at the same time affect wellbeing in the context of human activity. In these mutually conditioned interactions, two processes playing a key role are the so-called landscape perception and landscape projection. This article presents: (1) a review of theories playing a key role in the development of knowledge on landscape perception; (2) the basis for landscape projection as a logical and creative continuation of perception processes; (3) an outline of the theory of physiognomic landscape structure and of possibilities for it to gain practical application; (4) the results of the first Polish research into the public’s expectations where quality of the landscape is concerned. Perception of the landscape entails the receipt of stimuli from surrounding space with the help of the senses. It serves primarily in knowledge-based transformation of landscape systems, in a manner that meets ever-more exacting requirements on the part of society when it comes to living in an environment of the highest quality. Only a little scientific work has been devoted to the process of landscape projection. This is therefore a new research field, just opening up, which has the potential to give rise to a group of space-projection theories.

Experimental and numerical investigation of railroad vehicle braking dynamics

2009 ◽  
Vol 223 (3) ◽  
pp. 255-267
Author(s):  
C Mellace ◽  
A P Lai ◽  
A Gugliotta ◽  
N Bosso ◽  
T Sinokrot ◽  
...  
Keyword(s):  
Equations Of Motion ◽  
The Body ◽  
Computer Algorithms ◽  
Coordinate Systems ◽  
State Equations ◽  
Relative Coordinates ◽  
Linear State ◽  
Cartesian Coordinate ◽  
Railroad Vehicle ◽  
Braking Dynamics

One of the important issues associated with the use of trajectory coordinates in railroad vehicle dynamic algorithms is the ability of such coordinates to deal with braking and traction scenarios. In these algorithms, track coordinate systems that travel with constant speeds are introduced. As a result of using a prescribed motion for these track coordinate systems, the simulation of braking and/or traction scenarios becomes difficult or even impossible. The assumption of the prescribed motion of the track coordinate systems can be relaxed, thereby allowing the trajectory coordinates to be effectively used in modelling braking and traction dynamics. One of the objectives of this investigation is to demonstrate that by using track coordinate systems that can have an arbitrary motion, the trajectory coordinates can be used as the basis for developing computer algorithms for modelling braking and traction conditions. To this end, a set of six generalized trajectory coordinates is used to define the configuration of each rigid body in the railroad vehicle system. This set of coordinates consists of an arc length that represents the distance travelled by the body, and five relative coordinates that define the configuration of the body with respect to its track coordinate system. The independent non-linear state equations of motion associated with the trajectory coordinates are identified and integrated forward in time in order to determine the trajectory coordinates and velocities. The results obtained in this study show that when the track coordinate systems are allowed to have an arbitrary motion, the resulting set of trajectory coordinates can be used effectively in the study of braking and traction conditions. The results obtained using the trajectory coordinates are compared with the results obtained using the absolute Cartesian-coordinate-based formulations, which allow modelling braking and traction dynamics. In addition to this numerical validation of the trajectory coordinate formulation in braking scenarios, an experimental validation is also conducted using a roller test rig. The comparison presented in this study shows a good agreement between the obtained experimental and numerical results.

Method of numerical estimating aerial images indicators quality for mapping purposes

2021 ◽  
Vol 968 (2) ◽  
pp. 29-37
Author(s):  
I.A. Anikeeva
Keyword(s):  
Random Noise ◽  
Experimental Studies ◽  
Aerial Images ◽  
Practical Application ◽  
Correct Color ◽  
Numerical Assessment ◽  
Airborne Imaging ◽  
Imaging Sensors ◽  
Color Rendering

The task of assessing the quality of aerial imagery, obtained for mapping, in terms of vision properties, is very ambiguous due to the lack of objective criteria and evaluation methods. A system of indicators for aerial images quality and methods of their numerical assessment is presented. The fine aerial image’s quality is characterized by a set of its structural and gradation properties. The structural properties of the image are determined by the actual spatial resolution and photographic sharpness. Gradation properties of an image are characterized by the correct color rendering, the level of random noise and information completeness indicators – haze, radiometric resolution and the percentage of information loss in illumination and shadows.Methods of evaluating these indicators are formulated, and their recommended and acceptable numerical values are determined analytically. To clarify and correct the obtained analytical recommended and acceptable numerical values of the image quality indicators of their practical application possibility and further experimental studies are necessary with materials, obtained through various airborne imaging sensors for mapping.

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