Quantitative Analysis of Inner Force Distribution and Load Capacity of Grasps and Fixtures

2002 ◽  
Vol 124 (2) ◽  
pp. 444-455 ◽  
Author(s):  
Youlun Xiong ◽  
Han Ding ◽  
Michael Yu Wang
Keyword(s):  
Quantitative Analysis ◽  
System Design ◽  
Load Capacity ◽  
Point Contact ◽  
Analytical Description ◽  
Engineering Practice ◽  
Force Distribution ◽  
Grasp Planning ◽  
Analysis And Design ◽  
Fixture System

This paper focuses on a quantitative analysis for grasp planning and fixture design based on an analytical description of point contact restraint. In the framework, the analysis deals with the fundamental concepts of restraint cone, freedom cone, force-determinacy and relative form closure. A method is presented to quantify the performance of a fixture (or grasp) with two major characteristics of inner force distribution and load capacity. Two different fixturing (or grasp) models of simplex grasp and elastic grasp are presented. It is shown that the performance of these two types of grasp (or fixturing) could be measured with different performance indices. A minimax index (MMI) and a volume measure are defined for evaluating a simplex grasp, while a measure using the tolerable range of differential motion in the twist space or the allowable load polyhedron in the wrench space would be suitable for quantifying robustness and load capability of an elastic fixture system. Furthermore, for fixture system design a geometric analysis and reasoning procedure is described for the design of locators, clamps and supplementary supports. The aim of these proposed analysis and design techniques is to provide a scientific foundation for automated grasping/fixturing system design in the engineering practice.

Quantitative Analysis Of X-Ray Images From Geological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 244-245
Author(s):  
J. M. Paque ◽  
R. Browning ◽  
P. L. King ◽  
P. Pianetta
Keyword(s):  
Quantitative Analysis ◽  
Bulk Composition ◽  
Principal Component ◽  
Analytical Description ◽  
Bulk Sample ◽  
Geological Samples ◽  
X Ray ◽  
Software And Hardware ◽  
And Storage ◽  
Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

scholarly journals Analisis dan Perancangan Sistem Informasi Eksekutif Pemasaran pada Distributor Alat Tulis Kantor: Studi Kasus pada Benza Prima

2011 ◽  
Vol 2 (2) ◽  
pp. 955
Author(s):  
Mohammad Subekti ◽  
Raden Bagus Rhesa Dharma Widjaya ◽  
Eileen Heriyanni ◽  
Giovani Dewi
Keyword(s):  
Information System ◽  
System Design ◽  
Information Search ◽  
Object Oriented ◽  
Marketing Strategies ◽  
Information System Design ◽  
Research Results ◽  
Analysis And Design ◽  
Fact Finding ◽  
Executive Information System

Executive information system (EIS) has been widely used in enterprises and institutions to help the executives make decisions quickly and accurately for the organization's business needs. A research is conducted to create a marketing executive information system that can produce analytic reports and comparison reports for the executive of Benza Prima. For information search the fact finding techniques is utilized by conducting surveys directly to the company to study the company needs and the running procedures. The executive information system design uses Object Oriented Analysis and Design (OOAD) methodology. The research results in an executive information system that produces report in forms of pivot tables and charts to help the Benza Prima executives make decisions. The marketing executive information system design is expected to provide analytic information that can be used by the Benza Prima executive as an analytic tool in planning marketing strategies. 

scholarly journals Preliminary Design Framework for the Power Gearbox in a Contra-Rotating Open Rotor

2020 ◽  
Author(s):  
Diana G. San Benito Pastor ◽  
Devaiah Nalianda ◽  
Vishal Sethi ◽  
Ron Midgley ◽  
Andrew Rolt ◽  
...  
Keyword(s):  
System Design ◽  
Load Capacity ◽  
Engine Performance ◽  
Maximum Load ◽  
Transmission System ◽  
Published Data ◽  
Planetary Gearbox ◽  
Open Rotor ◽  
Parametric Analyses ◽  
The Impact

Abstract This study introduces an innovative approach to sizing a differential planetary gearbox for a counter-rotating open rotor application. An updated methodology is proposed for the design of maximum load capacity gears based on the power transmitted, durability and space-envelope requirements of the application. The reported methodology has been validated by comparing the results to published data, demonstrating a maximum difference of 0.6% in geometry. Parametric analyses have also been performed to assess the impact of the design assumptions on gearbox dimensional trends. The proposed methodology enables the assessment of the impact of the preliminary transmission system design on engine performance and general arrangement. The characteristics of the gearset lead to an unequal torque split between output shafts (i.e. the propeller shafts). Given the design assumptions made, the study indicates that valid torque ratios would lie between 1.1 and 1.33. The impact of the torque ratio on the size of the gearbox has been analysed for equal rotational speeds and for different speeds between the output shafts. The study established that the transmission system design needs to be considered prior to selection of the torque ratio at engine design level.

Fatigue Analysis of a Jacket Structure to Linear and Weakly Nonlinear Random Waves

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Naser Shabakhty ◽  
Arash Khansari
Keyword(s):  
Dynamic Response ◽  
Engineering Practice ◽  
Linear Wave ◽  
Fe Model ◽  
Random Waves ◽  
Weakly Nonlinear ◽  
Analysis And Design ◽  
Jacket Structures ◽  
Wave Models ◽  
Nonlinear Random Waves

Jacket structures have been widely used in oil and gas industry and are increasingly becoming competitive as a support structure of wind turbines at different water depths. These types of structures usually fix in transition or shallow waters where numerous field observations and experiments have shown that water particles tend to exhibit non-Gaussian characteristics. However, current engineering practice ignores the wave nonlinearity for the analysis and design of these structures. The application of linear irregular models might result in considerable uncertainties in the obtained wave loads and consequently the dynamic response and thus it is highly questionable. Therefore, it is crucial to calculate the dynamic response of jacket structures under both linear and nonlinear wave models to investigate the validity of linear wave models in different sea states. In this paper, the finite element (FE) model of a jacket structure located in Persian Gulf (SP17 jacket) is setup and applied to perform a comparative study of the dynamic response to both linear and weakly nonlinear random waves. The fatigue life of the jacket structure is then calculated under both wave models. This paper will substantially improve the understanding of the dynamic response of jacket structures under fatigue damage.

Object-Based Interactive Control System Design and Analysis

2003 ◽  
Author(s):  
Yong Zhu ◽  
Bo Chen ◽  
Harry H. Cheng
Keyword(s):  
Control System ◽  
System Design ◽  
Three Dimensional ◽  
Control System Design ◽  
Interactive Control ◽  
Analysis And Design ◽  
Modeling Analysis ◽  
Object Based ◽  
Practical Engineering ◽  
Numerical Computing

Ch is an embeddable C/C++ interpreter. It was developed to allow software developers to use one language, anywhere and everywhere, for any programming task. Ch supports C99, a latest C standard ratified in 1999, and contains salient features for two and three dimensional plotting and numerical computing for applications in engineering and science. Developed in Ch, Ch Control System Toolkit provides a control class with member functions for object-based interactive modeling, analysis, and design of control systems. The software package has been widely used in industry to solve practical engineering problems and in universities for instructional improvement. The design and implementation of Ch Control System Toolkit are described in this paper. An application example of control system design and analysis using Ch Control System Toolkit demonstrates its power and simplicity.

An Experimental Study of Static and Dynamic Characteristics of a 580mm(22.8in.) Diameter Direct Lubrication Tilting Pad Journal Bearing

2005 ◽  
Vol 128 (1) ◽  
pp. 146-154 ◽  
Author(s):  
Kazunori Ikeda ◽  
Toshio Hirano ◽  
Tatsuo Yamashita ◽  
Makoto Mikami ◽  
Hitoshi Sakakida
Keyword(s):  
Dynamic Characteristics ◽  
Large Scale ◽  
Load Capacity ◽  
Metal Temperature ◽  
Film Pressure ◽  
Static And Dynamic Characteristics ◽  
Oil Film ◽  
Analysis And Design ◽  
Tilting Pad ◽  
Oil Film Pressure

Direct lubrication tilting pad journal bearings (DLTPJ bearings) have rarely been applied to large-scale rotating machinery, such as turbines or generators, whose journal diameters are more than 500mm. In this paper, static and dynamic characteristics of a 580mm(22.8in.) diameter DLTPJ bearing were studied experimentally using a full-scale bearing test rig. In the static test, distribution of metal temperature, oil film pressure, and bearing loss were measured in changing oil flow rate, with mean bearing pressure ranging up to 2.9MPa. The maximum metal temperature of the DLTPJ bearing was compared to that of a conventional flood lubrication bearing, and it was confirmed that the direct lubrication could increase load capacity. In the dynamic test, spring and damping coefficients of oil film were obtained by exciting the bearing casing that was floated by air bellows. These data will be used for analysis and design of steam turbine rotors and their bearing systems. Also, vibration of pads was investigated because metal failure on upper pads due to vibration has been found in some actual machines. In order to generate oil film pressure on the surface of upper pads, a Rayleigh-step was machined there, and it was confirmed that vibration was reduced by the Rayleigh-step.

Analysis of Force Distribution in Grasps Using Augmentation

1996 ◽  
Vol 210 (1) ◽  
pp. 15-22 ◽  
Author(s):  
J S Dai ◽  
D R Kerr
Keyword(s):  
Rigid Body ◽  
Equilibrium Condition ◽  
Jacobian Matrix ◽  
Point Contact ◽  
Force Distribution ◽  
Mathematical Basis ◽  
New Approach ◽  
Contact Points ◽  
Geometric Compatibility ◽  
Force Equilibrium

A new approach to the analysis of statically indeterminate restraint of a rigid body with any arrangement of point contact is presented in this paper. The paper associates the elasticity at restraint contacts with geometric compatibility of the contact points and constructs elastic compatibility equations, which are complementary to the restraint equations. The equations so obtained are then used to augment the restraint equations and lead to an agumented Jacobian matrix. The new approach enables grasps to be analysed and synthesized in a constraint of combined elasticity and geometric compatibility, in addition to the force equilibrium condition. This gives a mathematical basis for the analysis of force distribution of the statically indeterminate restraint. Detailed reasoning and derivations are given followed by both planar and spatial examples.

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