An Energy Analyser for Contrast Enhancement in STEM

1974 ◽  
Vol 32 ◽  
pp. 434-435
Author(s):  
H.T. Pearce-Percy
Keyword(s):  
Contrast Enhancement ◽  
Bending Angle ◽  
Magnetic Sector ◽  
Conventional Design ◽  
Bending Radius ◽  
Sector Type

Recently an energy analyser of the uniform magnetic sector type has been installd in a 100KV microscope. This microscope can be used in the STEM mode. The sector is of conventional design (Fig. 1). The bending angle was chosen to be 90° for ease of construction. The bending radius (ρ) is 20 cm. and the object and image distances are 42.5 cm. and 30.0 cm. respectively.

Incremental Bending of Ultra-High-Strength Steels

2011 ◽  
Vol 473 ◽  
pp. 53-60 ◽  
Author(s):  
Antti Määttä ◽  
Kari Mäntyjärvi ◽  
Jussi A. Karjalainen
Keyword(s):  
Automotive Industry ◽  
Rolling Direction ◽  
High Strength Steels ◽  
High Strength ◽  
Roll Forming ◽  
Complex Phase ◽  
Bending Angle ◽  
Bending Radius ◽  
Ultra High Strength Steels ◽  
Traditional Manner

Utilisation of ultra-high-strength steels (UHS) has increased, particularly in the automotive industry. By using these materials vehicle structures can be lightened. However, one of the problems of UHS is weak formability. Materials fracture easily with small bending radii and the minimum bending radii are rather large. In this study, the tested materials were complex phase (CP) bainitic-martensitic UHS steels (YS/TS 960/1000 and 1100/1250). The steels were incrementally bent with a press brake in the rolling direction and perpendicular to it, and the final bending angle was 90 degrees. The incremental bending angles were 150°, 130°, 110° and 90°. The punch was unloaded after every incremental bending step. The test materials were bent with different bending radii. The aim was to find the minimum bending radius which produces an acceptable bend. Every incremental bend was compared with a bending performed in the traditional manner. The aim of this study was to examine how well the results of incremental bending compare to roll forming. In addition, clarification studies of when the bend started to fracture were made. It is well known that steels are more efficiently bent by roll forming compared with traditional bending. The results presented in this study demonstrate that incremental bending does not produce better results than traditional bending. Nevertheless, it has been shown that the examined steels can be bent incrementally against manufacturer’s recommendations.

Study of NC Cold Tube Bending Spring-Back Characteristics

2010 ◽  
Vol 154-155 ◽  
pp. 202-208 ◽  
Author(s):  
Yi Nan Lai ◽  
Sheng Le Ren ◽  
Zeng Lou Li ◽  
Jun Tao Gu ◽  
Guang Fei Wu
Keyword(s):  
High Reliability ◽  
Prediction Equation ◽  
Strong Nonlinearity ◽  
Spring Back ◽  
Tube Bending ◽  
Bending Angle ◽  
Bending Process ◽  
Elasto Plasticity ◽  
Bending Radius ◽  
Back Angle

The unloading spring-back of tubes during its manufacturing process shows a strong nonlinearity, which greatly influences the precision of parts. In this paper, the strain distribution of bending tubes was analyzed based on the elasto-plasticity theory, and the theoretical equation for spring-back of tubes was derived. The numerical simulation model for cold tube-bending process was developed with prediction error of 9% compared with experimental results, indicating high reliability of the model. The 12Cr1MoV and 20G tubes were used to analyze the effects of bending angle, bending radius and bending speed on the spring-back of tubes. The prediction equation of spring-back was built, which shows that the spring-back tendency was in accordance with theoretical analysis results. The simulated results show that the spring-back angle is linearly proportional to the bending angle within a certain range. In addition, it is proportional to the relative bending radius and the bending speed.

Application of a Magnetic Sector type Hydrogen Analyzer For Engine Emission Measurement

2001 ◽  
Author(s):  
Shigeru Nakatani ◽  
Feibo Wang ◽  
Masaaki Ishihara ◽  
Masayuki Adachi ◽  
Kozo Ishida
Keyword(s):  
Emission Measurement ◽  
Magnetic Sector ◽  
Sector Type ◽  
Engine Emission

Biomimetic Universal Blade Test Analysis

2012 ◽  
Vol 482-484 ◽  
pp. 196-199
Author(s):  
Zhuo Shi Li ◽  
Zeng Hui Wang
Keyword(s):  
Experimental Results ◽  
Test Analysis ◽  
Bending Angle ◽  
Unit Width ◽  
Cutting Angle ◽  
Blade Width ◽  
Bending Radius ◽  
Set Up

The experiment on four factors (bending angle, bending radius, tangent edge sliding cutting angle, operating width) that affect the single-pole unit width twist of rotary-broken universal blade is done using orthogonal experimental method.The paper respectively set up the function operations of single-pole unit width twist and bending angle, bending radius, tangent sliding cutting angle, and single-pole blade width according to experimental results. By these function operations, the paper analyze the value and scope of various factors in order to minimize the single-pole unit width twist under the conditions of rotary experiment.

A Study on the Nose Radius Influence in Press Brake Bending Operations by Finite Element Analysis

2013 ◽  
Vol 554-557 ◽  
pp. 1432-1442 ◽  
Author(s):  
J. Bessa Pacheco ◽  
Abel D. Santos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sheet Metal ◽  
Computer Control ◽  
Nose Radius ◽  
Forming Process ◽  
Element Analysis ◽  
Bending Angle ◽  
Air Bending ◽  
Bending Radius

The sheet metal bending is one of the metal forming processes with the simplest geometric interpretation and usually a 2D analysis is considered. The bend over a sheet metal blank consists of a V shape forming by using a punch, with a certain nose radius, forcing the plate against an open die, with a V section. The forming result is a part with an angle obtained between the V legs, flanges, which is known as bending angle. The operation to get the required V angle is called air bending, or free bending. The most common used machines for this forming process are press brakes, special long presses, where the tools, punch and die, are attached to. With the spread use of CNC machines, and their computer control capabilities, most of them using graphical user interface (GUI), became important to get the required shape at first trial. Beyond the required bending angle obtained with just one hit, it is also important to position the gauge system in order to get the successive flange lengths to complete the programmed shape. The main variables controlled by the CNC are the punch penetration inside the die and the position of the back gauge, which is determined by the bend allowance. However this penetration is not the only responsible for the resulting bending angle and the gauging position is not the only responsible for the flange length. Additionally, the radius inside the V shape edge, known as bending radius, influences the geometry and correspondingly the bend allowance. Some authors believe that the punch nose radius has direct influence, both in the bending angle and bend allowance. In this paper, results are presented describing the use of finite element analysis as an aid in the prediction of the inside bending radius, that influences both punch penetration for the final bending angle and the bend allowance for the final flange length. From the air bending analysis, a natural inside bending radius is presented as an important variable in these kind of processes, as well as its minor dependence on the punch nose radius.

scholarly journals Parametric Analysis of Tube during Bending Operation

2019 ◽  
Vol 8 (10) ◽  
pp. 1793-1799
Keyword(s):  
Software Package ◽  
Parametric Analysis ◽  
Air Conditioning ◽  
Industrial Applications ◽  
Furniture Industry ◽  
Bending Angle ◽  
Shipbuilding Industry ◽  
Material Deformation ◽  
Bending Process ◽  
Bending Radius

Bent tubes have a lot of various industrial applications. It is required for the transportation of fluids or gases. It also used as construction elements in all industries like car, aviation and shipbuilding industry, refrigeration and air conditioning technology, furniture industry. The objective of this paper is to understand the material deformation occurring during the bending of the tube bends and study the effect of parameters viz. bending radius, bending angle, springback on ovality of tube during bending operation. Tube undergoes certain deformation during the bending process which introduces various defects in the tube bends. This will lead the acceptability of tube bends for certain application. For better understanding the approximation of the defect it is necessary to reduce it at the manufacturing level itself. The testing uses different bending die to differ the bending radius and tests are performed at different bending angle. These whole data has been used to find the different defects and also to find the stress induced in the bends using FEA software package.

Research on the Springback of Square TA18 Titanium Alloy Tube on the Numerical Simulation

2019 ◽  
Vol 944 ◽  
pp. 753-760 ◽  
Author(s):  
Cong Liu ◽  
Xiao Dong Yan ◽  
Yin Yang ◽  
Wei Ye
Keyword(s):  
Numerical Simulation ◽  
Titanium Alloy ◽  
Process Parameters ◽  
Three Dimensional ◽  
Outer Wall ◽  
Element Model ◽  
Bending Angle ◽  
Alloy Tube ◽  
Bending Radius ◽  
Titanium Alloy Tube

This paper focuses on how bending and springback process of the titanium tubes with different bending radius and bending angle affect the springback rate after unloading and analyses tube distributions and variations of stress and strain by establishing a three-dimensional elastic-plastic finite element model of square TA18 titanium alloy tube based on ABAQUS/explicit and ABAQUS/standard. It is shown that under the same process parameters, the sprignback rate obtained by numerical simulation is in good agreement with that measured in the experiments. The springback rate after unloading increases with the increase of the bending radius linearly, and it increases nonlinearly with the decrease of bending angle. The distribution of the tube-roundness and the relationship between its roundness and springback rate under different process parameters could be obtained by comparing the variation of the absolute value of its outer wall unit at the maximum principal strain before and after unloading.

scholarly journals Flow characterisation in an exhaust manifold of a single-cylinder internal combustion engine (ICE)

2021 ◽  
Vol 2129 (1) ◽  
pp. 012077
Author(s):  
N A Aziz ◽  
M T A Rahman ◽  
N A M Amin ◽  
M S Bin Mohamad ◽  
A Mohamad ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Flow Characteristic ◽  
Combustion Engine ◽  
Fluid Dynamic ◽  
Exhaust System ◽  
Exhaust Manifold ◽  
Bending Angle ◽  
Bending Radius ◽  
Manifold Models ◽  
Cfd Method

Abstract This paper presents an investigation of flow characteristic inside the exhaust manifold that were designed with different bending angle (BA), bending radius (BR) and pipe diameter (Dp ). Five exhaust manifold models were developed and analysed by the computational fluid dynamic (CFD) method. Accordingly, the pressure distribution, velocity streamline and backpressure values were observed. The simulation results showed a different flow pattern for all five models, indicating the manifold design affect the flow characteristic inside the exhaust system. The results demonstrated that the pressure distribution inside the exhaust manifold is influencing its velocity streamline pattern, that directly effecting the outlet velocity of the exhaust gas. From this work, a small bending angle with a short straight pipe has led to a smoother exhaust flow and even exhaust velocity across the model. The results obtained from the simulation can be used as a guide to improve the understanding of the flow behaviour in the manifolds and might be used to improve the manifold design.

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