Projectivity of Im 𝐽, cospherical classes and geometric dimension

1998 ◽  
pp. 181-186
Author(s):  
Kee Lam ◽  
Duane Randall
Keyword(s):  
Geometric Dimension

Design and Manufacturing of Cylinder-Beam Integrated Hydraulic Press

2013 ◽  
Vol 397-400 ◽  
pp. 157-161
Author(s):  
Wei Wei Zhang ◽  
Xiao Song Wang ◽  
Shi Jian Yuan ◽  
Zhong Ren Wang
Keyword(s):  
Driving Force ◽  
Geometric Dimension ◽  
Hydraulic Cylinder ◽  
Hydraulic Press ◽  
Force Distribution ◽  
Section Modulus ◽  
The Press ◽  
The World ◽  
Design And Manufacturing ◽  
Institute Of Technology

For a cylinder-beam integrated hydraulic press (CBIHP), the hydraulic cylinder is also functioned as an upper beam. It is the key structural component that outputs the driving force to forge parts. Compared with the traditional three-beam and four-column hydraulic press which has a cylindrical hydraulic cylinder, the structure and force distribution are significantly different for CBIHP. It is able to have higher nominal force and larger section of plunger which the pressure is applied on when the contour geometric dimension is the same. Also, CBIHP has lighter weight and larger section modulus when the nominal force is the same than the traditional hydraulic press. Finally, a 6300KN cylinder-beam integrated hydraulic press, which is the first CBIHP in the world and designed by Harbin Institute of Technology (HIT) in 2012, is also introduced in this paper. It can be seen from the results of numerical simulation for the CBIHP that both of the stresses and displacements on the press in the loading process are allowable.

scholarly journals Transient Analysis of Thermal Treatment Processes Carburizing and Nitriding of Steel Components by Numerical Modeling and Simulation

2019 ◽  
Vol 9 (2) ◽  
pp. 2584-2593
Keyword(s):  
Differential Equation ◽  
Numerical Modeling ◽  
Ambient Temperature ◽  
Modeling And Simulation ◽  
Geometric Dimension ◽  
Rate Of Change ◽  
Critical Parameters ◽  
Numerical Modeling And Simulation ◽  
Linear Differential ◽  
Energy Balance Approach

The purpose of carburizing, nitriding and carbonitriding is to increase the strength of components. Elements such as carbon, nitrogen and carbon-nitride are diffused into the components at high temperature convective environment. The amount of diffusion is to be regulated by controlling the temperature and time of diffusion. Time and temperature of process govern diffusion rate and strength of the component. Numerical modeling is applied by energy balance approach i.e., equating rate of change of energy is equal to energy transferred by conduction, convection and radiation. By non dimensionalising relations for the mentioned critical parameters were obtained. The phenomenon of convection, radiation and conduction are taken together for the purpose of numerical modeling. Variation of temperature and depth of diffusion of component for the taken components i.e., sphere and cube was plotted in transient state. For both numerical analysis and simulation the boundary conditions i.e., for carburization the ambient temperature is 9500C with carbon monoxide as the carburizing agent and for nitriding the ambient temperature is 5300C with nitrogen as nitriding agent and the component taken is of steel which is initially at room temperature were taken. Results obtained from numerical modeling and simulation were compared with each other and observed that in both analyses the variation of temperature with time and depth of diffusion is almost linear. Final differential equation obtained in numerical modeling is a single order non linear differential equation which is solved in MATLAB using finite difference approach. Data obtained from MATLAB were plotted for variation of surface temperature and geometric dimension with respect to time.

Study on Machining Deformation Errors in Spiral Finish Milling of Thin-Walled Blades

2011 ◽  
Vol 314-316 ◽  
pp. 1773-1777
Author(s):  
Wei Wei Liu ◽  
Pei Chen ◽  
Xiao Juan Gao ◽  
Chen Wei Shan ◽  
Min Wan
Keyword(s):  
Geometric Dimension ◽  
Beam Theory ◽  
Milling Process ◽  
Simplified Model ◽  
Machining Deformation ◽  
Proposed Model ◽  
Thin Walled ◽  
The Relationship ◽  
Torsion Deformation

In this paper, a new procedure is proposed to study the deformation errors for spiral milling process of blade, which can be simplified as a stepwise beam based on the geometry and clamping characteristics. Kirchhoff beam theory is adopted to analyze the bending and torsion deformation. The relationship between machining deformation errors and the workpiece’s geometric dimension are also established based on the simplified model. Corresponding algorithms are realized by MATLAB codes. Experiment test shows that the results predicted by the proposed model are in well agreement with measured ones.

Feature Recognition and Datum Extraction for Setup Planning and Operation Sequencing for Prismatic Parts

2012 ◽  
pp. 102-129
Author(s):  
T. Srikanth Reddy ◽  
M. S. Shunmugam
Keyword(s):  
Feature Recognition ◽  
Geometric Dimension ◽  
Connectivity Matrix ◽  
Setup Planning ◽  
Priority Rules ◽  
Operation Sequencing ◽  
Prismatic Parts ◽  
Manufacturing Activity ◽  
Edge Features ◽  
Planning And Operation

An automated planning system extracts data from design models and processes it efficiently for transfer to manufacturing activity. Researchers have used face adjacency graphs and volume decomposition approaches which make the feature recognition complex and give rise to multiple interpretations. The present work recognizes the features in prismatic parts considering Attributed Adjacency Matrix (AAM) for the faces of delta volume that lie on rawstock faces. Conceptually, intermediate shape of the workpiece is treated as rawstock for the next stage and tool approach direction is used to recognize minimum, yet practically feasible, set of feature interpretations. Edge-features like fillets/undercuts and rounded/chamfer edges are also recognized using a new concept of Attributed Connectivity Matrix (ACM). In the first module, STEP AP-203 format of a model is taken as the geometric data input. Datum information is extracted from Geometric Dimension and Tolerance (GD&T) data. The second module uses features and datum information to arrive at setup planning and operation sequencing on the basis of different criteria and priority rules.

Fractal perspectives in pulmonary physiology

1991 ◽  
Vol 71 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J. E. McNamee
Keyword(s):  
Three Dimensional ◽  
Geometric Dimension ◽  
Bronchial Tree ◽  
Pulmonary Vasculature ◽  
Two Dimensional ◽  
Mathematical Functions ◽  
Pulmonary Tissue ◽  
Pulmonary Physiology ◽  
New Perspective ◽  
Class Of Functions

Like other organs that exchange substantial quantities of material with blood, the lung accommodates a large two-dimensional surface in a component three-dimensional volume. The lung's structure shows a resemblance to certain one- and two-dimensional mathematical functions that possess plane- and space-filling properties. When viewed from a conventional geometric perspective, many of the familiar forms and functions of pulmonary tissue appear to possess unusual qualities that defy explanation. Mathematically, they behave as though they had a fractional geometric dimension. This property is shared by a class of functions known as fractals. Fractals are described, and practical techniques are presented to measure the properties of the edges and surfaces of the lung. The consequences of fractal structure are also considered for the bronchial tree, pulmonary vasculature, and microcirculation. Insights arising from viewing the lung in this new perspective are summarized.

Study on geometric dimension design of multiheat teeming tundish for heavy steel ingots

2012 ◽  
Vol 39 (2) ◽  
pp. 140-146 ◽  
Author(s):  
J Li ◽  
G H Wen ◽  
P Tang ◽  
M M Zhu
Keyword(s):  
Geometric Dimension ◽  
Steel Ingots

Effects of Continuous Rolling Speed Change Rates on Geometric Dimension between Two Racks when Rolling Rail by Universal Pass

2012 ◽  
Vol 538-541 ◽  
pp. 2941-2944
Author(s):  
Yu Yan Liu ◽  
Yang Wang ◽  
Hu Zhu ◽  
Lin Chen
Keyword(s):  
Geometric Dimension ◽  
Dimensional Accuracy ◽  
Continuous Rolling ◽  
Distribution Law ◽  
Finite Element Software ◽  
Universal Mill ◽  
Speed Change ◽  
Rolling Deformation ◽  
The Relationship ◽  
Heavy Rail

This paper used the finite element software to simulate the process of the heavy rail rolling deformation between the UR and ER racks. It studied on the stress distribution law of the universal mill pass, the relationship between the universal mill unbalanced rates of velocity and tension changes of the rack, effect of the universal mill unbalanced rates of velocity on the change of the rolling geometric dimensions caused by the unbalanced rates of velocity. The research can guide the adjustment of the dimensional accuracy of the rail’s universal rolling.

Effect of geometric dimension on the stress in solar panel under temperature field

2005 ◽  
Vol 59 (16) ◽  
pp. 2064-2069 ◽  
Author(s):  
Xiaoyan Wang ◽  
Hongbin Geng ◽  
Shiyu He ◽  
Dezhuang Yang
Keyword(s):  
Temperature Field ◽  
Geometric Dimension ◽  
Solar Panel

Numerical and Experimental Research on Warm Tension-Rotation Bending of Extruded AZ31 Profile

2011 ◽  
Author(s):  
Shi-hong Zhang ◽  
Han Xiao ◽  
Jin-song Liu ◽  
Ming Cheng
Keyword(s):  
Main Parameter ◽  
Geometric Dimension ◽  
Element Model ◽  
Bending Test ◽  
Test Machine ◽  
Rotary Draw Bending ◽  
Bending Process ◽  
Forming Temperature ◽  
Dimensional Variation ◽  
Draw Bending

Magnesium alloy profiles have attracted more and more attention in automobile and aerospace industries. The rotary draw bending process is suitable to form profiles. A bending test machine is developed to conduct AZ31 profile bending experiment. A 3D elastic-plastic thermo-mechanical coupled finite element model is established and validated by experiment. The effects of process parameters on the geometric dimension of the profile were analyzed by using experimental and numerical methods. The results indicate that the pretension amount is the main parameter which influences the geometric dimension of the bent profile, then the forming temperature, following the bending angle. The dimensional variation of the middle-rib is relatively little, and the dimensional variations of the inside and the outside of the bent profile are large.

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