Clayton O. Ruud

Developing and conducting an industry based capstone design course

In an increasingly competitive marketplace, todays engineering graduate must be equipped to meet the needs of industry and these needs are not limited to technical competence. They include the ability to: consider alternative solutions and their impact on various operations; work in interdisciplinary teams; manage projects; tie projects to the bottom line profitability of the enterprise; and communicate effectively. In many cases, graduates are ill-prepared to meet these challenges. The Penn State Department of Industrial and Manufacturing Engineering, USA, has designed, developed and conducted a senior capstone course to address certain key skill deficiencies of the engineering graduate. The course is conducted in cooperation with parallel sections in Mechanical and Aerospace Engineering and as a consequence, many of the student teams are composed of students from all three disciplines. The course provides the student with a realistic experience that helps with the transition from theory to the real practice of engineering. This paper identifies those elements in the design and conduct of the course that ensures a good experience for both industrial partners and students. Important concepts such as selecting good industrial sponsors and coaching versus supervising are discussed.

A Review of Nondestructive Methods for Residual Stress Measurement

This paper summarizes the findings of a study whose objective was to review the state of the art of nondestructive residual stress measurement methods, evaluate the practical applicability of each to metallic engineering components, place the methods in perspective with respect to each other, develop a prognosis for advancements, and determine the most prudent areas for research investment. Also, the study was to provide elementary descriptions of the important principles of the various techniques as well as the application and limitations of each.

Rapid prototyping and freeform fabrication

In the course of industrial product development, a point comes when the product concept must move from engineering drawing to physical reality. The activity surrounding this point of first substantiation of a product concept can be labeled prototyping. Prototyping is important because it is the ultimate means for verifying product concepts. Because it is the first substantiation of a product, prototyping can be very expensive and time-consuming. This is the basis for seeking methods of rapid prototyping. Rapid prototyping (RP) offers the lure of faster, cheaper product development which can ultimately impact customer satisfaction and future profits.

THE DEVELOPMENT OF A MATHEMATICAL MODEL FOR PREDICTING THE DEPTH OF PLASTIC DEFORMATION IN A MACHINED SURFACE

ABSTRACT The development and verification of a mathematical model for the prediction of plastic deformation in a machined surface are presented. The main assumption for developing this model is that there is a linear relation between plastic strain and the depth to which it extends. The model relates the work required to shear the workpiece material to the work needed to compress the workpiece material ahead of the cutting tool. The resulting depth of plastic deformation in the machined surface is a function of the true stress-strain characteristics of the workpiece material, the shear stress and shear strain on the shear plane, and the distribution of plastic strain. Results of the model agree well with data found in the literature. An improvement of the model is suggested through application of actual distribution data of plastic strain and calculation of frictional behavior on the rake face of the tool.

Displacement Errors in the Application of Portable X-Ray Diffraction Stress Measurement Instrumentation

The role of residual stresses in the premature failure of metallic components has long been recognized. However, the most prevalent methods of measuring these stresses are at least partly, if not completely, destructive. This, as well as the availability of more rapid and portable x-ray diffraction instrumentation, has led to a renewed interest in this nondestructive residual stress measurement methodology.

Electron-Optical Characterization of Laterites Treated with a Reduction-Roast/Ammoniacal-Leach System

The U.S. Department of the Interior, Bureau of Mines, is developing a method to recover nickel, cobalt, and copper from low-grade domestic laterites in accordance with its goal to help maintain an adequate supply of minerals to meet national, economic and strategic needs. The metals are recovered by a system that incorporates selective reduction and a controlled oxidizing ammonia/ammonium sulfate leach with solvent extraction and electrowinning.

The measurement of neutron cross sections for contrast-enhancing penetrant fluids

The purpose of this experiment was to evaluate penetrant fluids of high neutron cross section. These fluids are useful in neutron radiographic investigations for contrast enhancement Saturated solutions of the gadolinium salts and one chelate were formed by using one of several solvents, and the resulting fluid’s macroscopic neutron cross sections were measured experimentally.The results of this experiment provided a quantitative measure of the mean and standard deviation of the macroscopic neutron cross section for the penetrant fluids. Inaddition, a confidence interval was generated for each fluid. The measured neutron cross section for a control fluid was in close agreement with published values.

Ultrasonic Prediction of Anisotropy in Copper and Copper Alloy Sheets

It is well recognized that the presence of preferred crystallographic orientation (texture) results in anisotropy of material properties [1–4]. To predict the plastic deformation response of materials where the texture character dominants, it is noted that a non-intrusive sensor system for on-line, in-process texture monitoring will meet the future demand of high quality in the final product, and total automation in manufacturing processes [5–8]. Several non-destructive techniques can be applied to extract quantitative information concerning anisotropic properties in materials. Ultrasonic techniques are one of them. Previous work has indicated the possibility of inferring texture from ultrasonic velocity measurements [9–11]. Mathematical formalisms have also been developed to relate ultrasonic velocity to texture-induced anisotropy [12–14]. However, few investigations have been performed regarding the nature of metallurgical parameters that affect the obtained ultrasonic velocity information. An understanding of these interdependent relationships will be necessary when trying to use ultrasonic velocity information for the purpose of materials characterization. It is the objective of this investigation to evaluate the effectiveness of ultrasonic velocity measurements as a means for prediction of material anisotropy.

The determination of three-dimensional stress tensors on multilayer thin films

The three-dimensional residual stress condition of copper sputtered on Kapton™ films was studied by two nondestructive x-ray diffraction techniques. Four samples were evaluated—one “control sample,” and three heat-treated samples. Because of concerns about steep stress gradients normal to the specimen surface, an experimental technique described by Dölle(1) was used to obtain the residual strain tensors in the near surface region. The resulting stress tensors were compared to data obtained through a modification of the technique described by Dölle, referred to as the differential method.(2)

A Nondestructive Observation of the Mechanism of Plastic Deformation in Orthogonal Cutting

Machining introduces a large amount of plastic deformation in the workpiece material and chip. This plastic strain is nonuniform, and therefore residual stresses are induced in the workpiece surface and subsurface throughout, and slightly below, the depth of plastic deformation. Thus, residual stresses are often an undesirable but unavoidable byproduct of machining. It is known that the mechanism of plastic deformation in metal is dislocation movement.