THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Data Mining Practical Machine Learning Tools and Techniques

This book, written by two major figures in adaptive control, provides a wealth of material for researchers, practitioners, and students. While some researchers in adaptive control may note the absence of a particular topic, the book‘s scope represents a high-gain instrument. It can be used by designers of control systems to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs. The book is strongly recommended to anyone interested in adaptive control.

Adaptive Control

A positive temperature coefficient is the term which has been used to indicate that an increase in solubility occurs as the temperature is raised, whereas a negative coefficient indicates a decrease in solubility with rise in temperature.

Effect of Temperature

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Ring rolling is an established method to produce seamless rings of different cross-sectional geometries. For dish shaped rings, there are applications in different areas such as offshore, aeronautics or the energy sector. At the moment, dish shaped rings are produced by machining of rings with rectangular shaped cross section, by (open die) hollow forging on a conical mandrel or by using shaped ring rolling tools. These ways of manufacturing have the disadvantage of high material waste, additional costs for special tools, long process time and limited or inflexible geometries. Therefore, the manufacturing of dish shaped rings on conventional radial-axial ring rolling mills would expand the range of products for ring producers. The aim of this study is to investigate the feasibility of an alternative to the current manufacturing processes, without requiring additional tooling and material costs. Therefore, the intended formation of dish shaped rings—previously regarded as a form error—is investigated. Based on an analysis of geometrical requirements and metal flow mechanisms, a rolling strategy is presented, causing dishing and ring climbing by a large height reduction of the ring. Using this rolling strategy dish shaped rings with dishing angles up to 18° were achieved. In addition to the experiments finite element method (FEM)—simulations of the process have been successfully conducted, in order to analyze the local strain evolution. However, when the contact between ring and main roll is lost in the process the ring starts to oscillate around the mandrel and neither dishing nor ring climbing is observed.

Manufacturing dish shaped rings on radial-axial ring rolling mills

For on-line prediction of roll force and torque, fast models have been available for a long time, which are mainly based on the slab method or other solution methods that allow for computing times in the range of seconds. Such fast models typically treat the rolling process as a plane strain problem and neglect shear deformation, which is always present in real processes. The shear deformation results in inhomogeneous strain profiles and thus might lead to inhomogeneity in microstructure over plate thickness. In this paper, a novel method is presented that allows for superposition of shear strain onto the strain state obtained from the slab method. The shear strains are interpolated from an extensive finite element (FE) parameter study of rolling processes that covers the entire parameter range of today’s plate rolling. For the regimes of very thick and thin plates different interpolation functions are introduced. It is shown that when the proposed shear strain model is combined with the slab method, similar results are obtained as with a full-scale FE calculation of the rolling problem but with a calculation time in the range of seconds.

Accounting for shear deformation in fast models for plate rolling

The present article describes design, architecture, and implementation of the Aachen (“Aix”) Virtual Platform for Materials Processing—AixViPMaP®. This simulation platform focuses on enabling automatic simulation workflows in the area of microstructure evolution and microstructure property relationships by continuum models. Following a description of a variety AixViPMaP® functionalities like user management, the currently implemented software tools, simulation workflows, data storage, grid infrastructure, and many more, some example workflows which have been run on AixViPMaP® are presented in detail. These workflow examples—although each being specific—can readily be transferred to other materials or to similar processes as the major simulation tools used in these workflows are all generic and thus applicable to a wide range of metals and technical alloys. The article concludes with a discussion on the performance and benefits of the platform, an outlook on its future development and on its open, future availability for both academic and commercial use.

/pdf/aixvipmap-an-operational-platform-for-microstructure-5e21xvesw3.pdf

AixViPMaP ® —an Operational Platform for Microstructure Modeling Workflows

Any production is based on materials. Material properties are of utmost importance, both for productivity as well as for application and reliability of the final product. A sound prediction of materials properties thus is highly important. For metallic materials, such a prediction requires tracking of microstructure and properties evolution along the entire component process chain. In almost all nature and engineering scientific disciplines the computer simulation reaches the status of an individual scientific method. Material science and engineering joins this trend, which permits computational material and process design increasingly. The Integrative Computational Materials and Process Engineering (ICMPE) approach combines multiscale modelling and through process simulation in one comprehensive concept. This paper addresses the knowledge driven design of materials and processes for forgings. The establishment of a virtual platform for materials processing comprises an integrative numerical description of processes and of the microstructure evolution along the entire production chain. Furthermore, the development of ab initio methods promises predictability of properties based on fundamentals of chemistry and crystallography. Microalloying and Nanostructuring by low temperature phase transformation have been successfully applied for various forging steels in order to improve component performance or to ease processing. Microalloying and Nanostructuring contribute to cost savings due to optimized or substituted heat treatments, tailor the balance of strength and toughness or improve the cyclic. A new materials design approach is to provide damage tolerant matrices and by this to increase the service lifetime. This paper deals with the numerically based design of new forging steels by microstructure refinement, precipitation control and optimized processing routes.

/pdf/designing-new-forging-steels-by-icmpe-1llsdgm4o3.pdf

Designing New Forging Steels by ICMPE

The miniaturization of sheet deep drawing is one possible solution for the production of metallic microparts. However, when reducing the product size to dimensions around 1 mm and using foils down to 40 μm, a reduction of process reproducibility is observed, also in industrial manufacturing. Consequently differences between “macro‐deep drawing” and “micro‐deep drawing” were studied by Finite Element Analysis and experimental investigations.Implicit axisymmetric 2D simulation was used to study the influence of transverse anisotropy, friction and deviations of process‐determining geometric factors, e.g. the drawing gap, on the micro deep drawing process for producing cups of 8 to 1 mm from CuZn37 foils with thicknesses from 300 to 80 μm. Deviations of tool geometry within the product tolerances of the tool can have a decisive influence on the deep drawing result. For example, the punch force changes by up to 12.8% if the drawing gap deviates from the nominal value by a few hundredths of a millimeter within ...

Gerhard Hirt

Papers

Manufacturing dish shaped rings on radial-axial ring rolling mills

Accounting for shear deformation in fast models for plate rolling

AixViPMaP ® —an Operational Platform for Microstructure Modeling Workflows

Designing New Forging Steels by ICMPE

Validation Of FEM‐Simulation For Micro Deep Drawing Process Modeling