Numerical 3D-modeling of spall and shear fractures in shells of austenitic 12Kh18N10T steel and 30KhGSA steel under their spherical and quasi-spherical explosive loading

2015 ◽  
Vol 06 (01) ◽  
pp. 1550011 ◽  
Author(s):  
Evgeny A. Kozlov ◽  
Oleg V. Ol'khov ◽  
Ekaterina V. Shuvalova
Keyword(s):  
3D Modeling ◽  
Laser Interferometry ◽  
12Kh18n10t Steel ◽  
Explosive Loading ◽  
Outer Radius ◽  
Experimental Setup ◽  
Paper Briefly ◽  
30Khgsa Steel ◽  
Scanning Electron ◽  
Explosive Layer

To pursue VNIIEF–VNIITF joint investigations, this paper briefly describes the experimental setup and provides numerical 3D-computation results (LEGAK-3D technique) on special features in the convergence dynamics of steel shells under their quasi-spherical explosive loading in the system with the 40-mm outer radius of the explosive layer. The computation results were compared with the data experimentally registered for shells of the 30KhGSA steel, both as-received and quenched to HRC 35…40, and the austenitic 12Kh18N10T stainless steel. The comparison was also made with laser-interferometry results obtained directly under explosive loading, as well as with gamma-tomography and scanning electron microscopy investigations of the recovered shells.

Micro-Manufacturing Using Online 3D Printing

2017 ◽  
Vol 872 ◽  
pp. 94-98
Author(s):  
Yi Ping Chen ◽  
Ming Der Yang
Keyword(s):  
3D Printing ◽  
3D Modeling ◽  
Mass Production ◽  
3D Model ◽  
Paper Briefly ◽  
Machining Processes ◽  
Micro Manufacturing ◽  
3D Printers ◽  
Subtractive Machining ◽  
Physical Components

As an additive manufacturing process, 3D printing provides conceptualizers and designers an opportunity to quickly produce physical components and concept models at reasonable costs. Such manufacturing is distinct from mass production involving traditional subtractive machining processes. This paper briefly describes microscale manufacturing involving a series of 3D-printing-related processes, including 3D modeling, 3D model slicing, printing, and production. Furthermore, specifications of 3D printers, a major component of the 3D printing process, impedes the entry of new micro-manufacturing businesses, such as the maximum printing volume, printing material, positioning accuracy, layer thickness, and price, were analyzed. In addition, online 3D printing service could be an alternative to overcome the difficulty of new entry to micro-manufacturing by a step-by-step instruction through internet. Commercially available online 3D printing services were surveyed and compared in material and cost in this paper.

scholarly journals A Simple Method to Increase the Amount of Energy Produced by the Photovoltaic Panels

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Daniel Tudor Cotfas ◽  
Petru Adrian Cotfas
Keyword(s):  
Electrical Energy ◽  
Experimental Setup ◽  
Paper Briefly ◽  
Simple Method ◽  
Photovoltaic Panels ◽  
Photovoltaic Energy

The photovoltaic energy can become competitive by the conjugate effort of the researchers and manufacturers. Increasing the amount of electricity supplied by photovoltaic panels is a challenge. The paper briefly presents some methods which can lead to achieving this goal. A simple method to increase the quantity of the electrical energy delivered by the photovoltaic panels is also presented in this paper alongside the experimental setup and the software created in LabVIEW for monitoring the output of the panels.

Analytical Model of the Confined Compression Test Used to Characterize Brittle Materials

2008 ◽  
Vol 75 (2) ◽  
Author(s):  
Sidney Chocron ◽  
James D. Walker ◽  
Arthur E. Nicholls ◽  
Kathryn A. Dannemann ◽  
Charles E. Anderson
Keyword(s):  
Analytical Model ◽  
Compression Test ◽  
Cylindrical Specimen ◽  
Failure Process ◽  
Testing Machine ◽  
Brittle Materials ◽  
Outer Radius ◽  
Confined Compression ◽  
Paper Briefly ◽  
Straightforward Approach

Numerical and analytical simulations of projectiles penetrating brittle materials such as ceramics and glasses are a very challenging problem. The difficulty comes from the fact that the yield surface of brittle materials is not well characterized (or even defined), and the failure process may change the material properties. Recently, some works have shown that it is possible to characterize and find the constitutive equation for brittle materials using a confined compression test, i.e., a test where a cylindrical specimen, surrounded by a confining sleeve, is being compressed axially by a mechanical testing machine. This paper focuses on understanding the confined compression test by presenting an analytical model that explicitly solves for the stresses and strains in the sample and the sleeve, assuming the sleeve is elastic and the specimen is elastoplastic with a Drucker–Prager plasticity model. The first part of the paper briefly explains the experimental technique and how the stress-strain curves obtained during the test are interpreted. A simple and straightforward approach to obtain the constitutive model of the material is then presented. Finally, a full analytical model with explicit solution for displacements, strains, and stresses in the specimen and the sleeve is described. The advantage of the analytical model is that it gives a full understanding of the test, as well as information that can be useful when designing the test (e.g., displacements of the outer radius of the specimen).

Improvement Corrosion Resistance of Gray Cast Iron Grade FC220 on Chromizing Process by Separate Cr Powder and NH4Cl Powder System

2015 ◽  
Vol 799-800 ◽  
pp. 397-401
Author(s):  
Pudsadee Chupong ◽  
Pijan Jornsanoh ◽  
Karuna Tuchinda ◽  
Anantawit Tuchinda
Keyword(s):  
Corrosion Resistance ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
Salt Spray ◽  
Gray Cast ◽  
Experimental Setup ◽  
Micro Hardness ◽  
Powder System ◽  
Iron Grade ◽  
Scanning Electron

A new configuration of chromizing process was developed by separating Cr powder from NH4Cl. FC220 gray cast iron specimens were chromized in this new experimental setup at 450, 550, 650,750, 850 and 950°C during 13 hours in order to study the possibility of chromizing at “low” temperature. The chromized specimens were examined using Scanning Electron Microscopy (SEM), macro-hardness, micro-hardness, compression test and salt spray test. The results shows that the specimen chromized at 650°C gives the best compromise between the corrosion resistance and the hardness of the FC220 with 1.73 ڌm of thickness of the chromized layer. However, after 13 hours of the process, the hardness of the FC220 specimens decreased considerably from 93 HRB to 64.2 HRB (31%).

Investigation of the Flow Regime and Flow Induced Vibrations (FIV) of the Control Rod Inside the Guide Channel of PWR

2017 ◽  
Author(s):  
Muhammad Ali ◽  
Lu Daogang ◽  
Zhang Huimin ◽  
Shahroze Ahmed ◽  
Muhammad Zeeshan Ali
Keyword(s):  
Fluid Flow ◽  
Flow Regime ◽  
3D Modeling ◽  
Displacement Sensor ◽  
Experimental Setup ◽  
Control Rod ◽  
Nuclear Core ◽  
Flow Induced Vibrations ◽  
Experimental Values ◽  
Vibration Modeling

The phenomenon of Flow induced vibrations (FIV) through the motion induced into the control rod of the nuclear core model apparatus due to high speed internal and external fluid flow. It involves a variety of flow phenomena around the restrictions and over a range of vibration frequencies of the control rod and other related components. The results of a CFD analysis are presented, which are compared with the experimental values obtained from the experimental setup specifically designed for solving and reviewing the fluid induced vibration problems, and thus forming equations of fluid flow regime and vibration modeling. The experimental setup is a model of a nuclear core consists of a fuel assembly without any fuel rod, a control rod held from a rigid screwed support and three fluid mixing plates similar to grid spacers with external and internal fluid flow. There are two inlets, forcing water from below and one of the sides of the apparatus while one outlet located above from both on the opposite side of the second inlet. The results of the experimental setup were detected by laser displacement sensor, to measure the vibration of the control rod, connected with a computer system. This vibration displacement data was measured under different flow conditions rendered due to different pressures through the inlet pumps. The different meshing results give a comparison of 3D modeling under different meshing strategies. Different group of inlet and outlet flow values have been considered according to the designed apparatus including velocities, pressure gradients to form the equations. The procedure followed for numerical method is starting from static fluid flow equations and moving on to the transient equations and thus forming the concluding equation. Similarly, the simulations have been improved from simple steady conditions to the transient solution while for the vibration modeling general modeling rules have been followed and different constants have been taken from the materials libraries available and the values of load from the experimental data and simulation. The results obtained from simulations represent that 3D modeling refinement makes it much complex and as known takes more time and needs heavy computing memories but the results are acceptable to the extent required. So the equations of fluid induced vibrations and fluid flow regime in a vertical nuclear core, by performing simulations of ANSYS CFX and FLUENTS and obtaining the experimental values and calibrating the values with those obtained from simulations as well as numerically solving the problem and finally comparing them all.

scholarly journals Experimental and Numerical Research in Explosive Loading of Two- and Three-Component Solid Mixtures

2013 ◽  
Vol 16 (1) ◽  
pp. 3 ◽  
Author(s):  
O.V. Ivanova ◽  
S.A. Zelepugin ◽  
A.S. Yunoshev ◽  
V.V. Sil’vestrov
Keyword(s):  
Axial Direction ◽  
Explosive Loading ◽  
Detonation Products ◽  
Explosive Compaction ◽  
Explosion Products ◽  
Joint Deformation ◽  
Numerical Research ◽  
Cylindrical Steel ◽  
Recovery Ampoule ◽  
Explosive Layer

We have conducted experimental and numerical research in two- and three-component solid mixtures placed into a cylindrical recovery ampoule under explosive loading. Behavior of the mixture is described by a mathematical model of a multicomponent medium. In the model, every component of a mixture simultaneously occupies the same volume as the mixture. Components interact with each other, exchanging momentum, energy, and mass (if the chemical reaction between the components occurs). An equality of components’ pressure is chosen as a condition for joint deformation of components. Finite element method is used for solving the problems. We considered experimentally and numerically explosive loading of the<br />aluminum-sulfur mixture, and explosive compaction of the aluminum-sulfur-carbon mixture in a cylindrical steel ampoule. The inert substance (graphite) was added to the mixture to avoid the reaction between aluminum and sulfur. Most of the focus is on simulating the action of explosion products on the ampoule.<br />In the computations the actions of the detonation products surrounding the ampoule was simulated by the action of pressure on the upper part of the ampoule in a vertical (axial) direction and on the lateral surface of the ampoule in a horizontal (radial) direction. We varied the thickness of the explosive that acts on the upper part of the ampoule in the axial direction in order to study the influence of the parameter on a final shape and size of the ampoule. We founded the essential influence of the thickness of the explosive layer on the final result of explosive compaction. Insufficient thickness of explosives, as well as the excessive thickness may be a reason for an incompletely compacted final product or lead to the formation of cracks or damage.<br /><br />

Convergence Analysis of a Steerable Nip Mechanism for Full Sheet Control in Printing Devices

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Edgar Ergueta ◽  
Rene Sanchez ◽  
Roberto Horowitz ◽  
Masayoshi Tomizuka
Keyword(s):  
Convergence Analysis ◽  
Local Control ◽  
Control Strategy ◽  
High Speed ◽  
State Feedback ◽  
Experimental Setup ◽  
Image Transfer ◽  
Paper Briefly ◽  
Transfer Station ◽  
Performance Specifications

Current approaches for high speed color printers require sheets be accurately positioned as they arrive to the image transfer station (ITS). This goal has been achieved by designing and building a steerable nip mechanism, which is located upstream from the ITS. This mechanism consists of two rollers that not only rotate to advance the paper along the track, but also steer the paper in the yaw direction. This paper briefly reviews the design and experimental setup of the system, and focuses on the design and analysis of a controller that precisely corrects the lateral, longitudinal, and angular positions of the sheet. The control strategy used is based on linearization by state feedback with the addition of internal loops for the local control of the actuators. This paper also provides a methodology to tune the controller parameters so that the desired performance specifications are met. The success of this mechatronic approach is corroborated through simulation and experimental results, which show that the system is able to correct sheet errors and meet all the performance specifications.

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