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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Roll bonding is a joining-by-forming process to permanently join two or more layers of different materials by hot or cold rolling. One of the typical industrial applications is aluminium sheets for heat exchangers in automobiles. During roll bonding the layers are fed into the rolling stand with parallel surfaces. Due to the plastic deformation in the roll gap metallic bonds between the layers are achieved. Several theoretical models have been published to describe the process, e.g. Zhang & Bay. These models have mostly been developed for cold rolling and describe the bond strength based on surface enlargement, contact pressure and flow stress. Since these models are developed for cold rolling, they are not temperature depending. Heat exchange is usually neglected and de-bonding after the roll gap is not accounted for. However, for hot roll bonding the above mentioned assumptions do not hold true. To understand the mechanisms of hot roll bonding industrial and laboratory scale investigations have previously been conducted. Based on the findings a FE framework for hot roll bonding was developed. This FE framework accounts for the possibility of de-bonding after the roll gap but is restricted to isothermal conditions. However, for a roll bonding simulation it is essential to take the temperature influence into consideration. Therefore, this paper presents an extended version of the FE framework which accounts for temperature dependent material flow, compatible definition of thermal & mechanical interactions and bonding status related heat exchange. To verify the new features of the extended FE framework a roll bonding test case is employed. Mechanical and thermal interactions as well as the current flow stress are calculated in subroutines in order to enable a fully coupled thermal stress simulation. The results show that with this extended FE framework the influence of non-isothermal conditions on material flow and bonding status as well as the feedback effects of bonding status to heat exchange have been successfully integrated in hot roll bonding simulations. This fully coupled thermal stress simulation is the first step towards multi-pass roll bonding simulations.

A New Coupled Thermal Stress FE-Model for Investigating the Influence of Non-Isothermal Conditions on Bond Strength and Bonding Status of the First Pass in Roll Bonding

Entwicklung von schnellen Prozessmodellen und Optimierungsmöglichkeiten für das Freiformschmieden

Untersuchung des Einflusses unterschiedlicher Prozessbedingungen auf die Reibung bei Umformprozessen

Design of Caliber Rolls Incorporating Load Path Dependent Damage Evolution

Herein, an alloy with 4.5 wt% Si is produced by twin‐roll casting and processed into a crack‐free electrical steel by warm rolling and final annealing. A comprehensive material characterization allows insight into the solidification structure, Si segregation, the microstructure, and texture evolution during the process chain, as well as into the soft magnetic properties of the produced electrical steel. A weak but favorable θ‐fiber is formed by twin‐roll casting and appears again in the final annealed state. Despite the high Si content, this leads to relatively high polarization values. Nevertheless, the expected low iron losses of the Fe–4.5Si alloy cannot be verified, which is probably related to impurities, insufficient flatness, and inhomogeneous grain size distribution.

Gerhard Hirt

Papers

A New Coupled Thermal Stress FE-Model for Investigating the Influence of Non-Isothermal Conditions on Bond Strength and Bonding Status of the First Pass in Roll Bonding

Entwicklung von schnellen Prozessmodellen und Optimierungsmöglichkeiten für das Freiformschmieden

Untersuchung des Einflusses unterschiedlicher Prozessbedingungen auf die Reibung bei Umformprozessen

Design of Caliber Rolls Incorporating Load Path Dependent Damage Evolution

Microstructure Evolution and Magnetic Properties of a 4.5 wt% Silicon Steel Produced by Twin‐Roll Casting