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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Konzepte zur integrierten Modellierung von Gefüge- und Fließspannungsentwicklung in der Simulation von Warmumformprozessen

Bistable metal shells with a fully closed unfolded geometry are of great interest as lightweight construction parts which could be transported without housing and unfolded at the construction place. In order to achieve the effect of bistability in metallic shells, residual stresses with a specific distribution along the shell thickness are necessary. These residual stresses can be introduced in bending processes. The tools with specific bending radii are used to influence the curvature of the shell in the different stable states and thus determine whether a completely closed profile can be achieved. In addition to the forming process, the shell thickness and the shell material have an effect on the achievable geometries and stability. In order to manufacture bistable metallic cylindrical shells from different materials and shell thicknesses, it is necessary to be able to determine a promising process sequence and corresponding bending radii in advance. For this reason, this article presents a semianalytical model for the calculation of bistability and final curvatures. This model is applied to an incremental die-bending process using two bending operations with bending radii of 6 to 12 mm and a 0.2 mm thick steel shell of grade 1.1274 (AISI 1095). The calculation results show that bistability cannot be reached for all combinations of the two bending radii. Moreover, the model indicates that a bistable and fully closed shell is only achieved for a bending radii combination of R1 = 6 mm and R2 = 6 mm. With the aim of model verification, experiments with a closed-die incremental bending tool were performed. Calculated and experimental results show good correlation regarding bistability and curvature. In addition, X-ray diffraction measurement of the residual stresses shows a good qualitative agreement regarding the calculated and experimental results.

https://www.mdpi.com/2504-4494/3/1/22/pdf

A Semianalytical Model for the Determination of Bistability and Curvature of Metallic Cylindrical Shells

For simulating metal forming processes by means of Finite Element programs it is required to define all tool motions beforehand. This is one of the major difficulties of the conventional Finite Elements Analysis (FEA) for simulating ring rolling processes, since in reality the motions are controlled by closed-loop control systems according to current sensor values. A solution is given by integrating control algorithms into the Finite Element model. In a previous publication the authors have presented a method in which the algorithms of an industrial control system of ring rolling machines are coupled with the Finite Element model. Although this approach enables modelling with realistic kinematic conditions, it has the major drawback that the algorithms of the used control are not disclosed to the users. Hence, it will not be possible to modify the controller for new processes and process optimization. In this paper, therefore, a set of reasonable and simple control algorithms is introduced, which can be u...

Realistic modelling of the tool kinematics of radial-axial ring rolling machines in finite element simulation

Flexible and economic production of composite structures which include functional layersrequires new manufacturing techniques. Joining by plastic deformation is a powerful technique whichis widely used in production processes to create metal composites [1]. The use of plastic deformationin joining processes offers improved accuracy, reliability and environmental safety [2]. The presentstudy deals with modeling of the bonding and debonding behavior in metallic composite structures.Therefore, a general cohesive zone element formulation in the framework of zero-thickness interfaceelements is developed. This enables the accurate and efficient modeling of the interface based on aninterfacial traction-separation law. The paper is concluded by a detailed description of the processsimulation and a comparison of its results with experimental data.

A Cohesive Zone Model for Simulation of the Bonding and Debonding in Metallic Composite Structures - Experimental Validations

Due to the nonlinear material behavior and contradicting application requirements, the selection of a specific electrical steel grade for a highly efficient electrical machine during its design stage is challenging. With sufficient knowledge of the correlations between material and magnetic properties and capable material models, a material design for specific requirements can be enabled. In this work, the correlations between magnetization behavior, iron loss and the most relevant material parameters for non-oriented electrical steels, i.e., alloying, sheet thickness and grain size, are studied on laboratory-produced iron-based electrical steels of 2.4 and 3.2 wt % silicon. Different final thicknesses and grain sizes for both alloys are obtained by different production parameters to produce a total of 21 final material states, which are characterized by state-of-the-art material characterization methods. The magnetic properties are measured on a single sheet tester, quantified up to 5 kHz and used to parametrize the semi-physical IEM loss model. From the loss parameters, a tailor-made material, marked by its thickness and grain size is deduced. The influence of different steel grades and the chance of tailor-made material design is discussed in the context of an exemplary e-mobility application by performing finite-element electrical machine simulations and post-processing on four of the twenty-one materials and the tailor-made material. It is shown that thicker materials can lead to fewer iron losses if the alloying and grain size are adapted and that the three studied parameters are in fact levers for material design where resources can be saved by a targeted optimization.

Gerhard Hirt

Papers

Konzepte zur integrierten Modellierung von Gefüge- und Fließspannungsentwicklung in der Simulation von Warmumformprozessen

A Semianalytical Model for the Determination of Bistability and Curvature of Metallic Cylindrical Shells

Realistic modelling of the tool kinematics of radial-axial ring rolling machines in finite element simulation

A Cohesive Zone Model for Simulation of the Bonding and Debonding in Metallic Composite Structures - Experimental Validations

Material Design for Low-Loss Non-Oriented Electrical Steel for Energy Efficient Drives.