Exam (elaborations) TEST BANK FOR Deformation and Fracture Mechanics of Engineering Materials 5Edition By Richard W. Hertzberg (Solution Manual)-Converted

In your own words, what are two differences between product testing and material testing? Possible answers include: (a) The goal of the two procedures is different. Whereas product testing is design to determine the lifetime of a component under conditions that mimic realworld use, material testing is intended to extract fundamental material properties that are independent of the material’s use. (b) The specimen shape is different. Product testing must use the material in the shape in which it will be used in the real product. Material testing uses idealized specimen shapes designed to unambiguously determine one or more properties of the material with the simplest analysis possible. 1.2 What are the distinguishing differences between elasticity, plasticity, and fracture? Elasticity involves only deformation that is fully reversible when the applied load is removed (even if it takes time to occur). Plasticity is permanent shape change without cracking, even when no load exists. Fracture inherently involves breaking of bonds and the creation of new surfaces. Often two or more of these processes take place simultaneously, but the contribution of each can be separated from the others. 1.3 Write the definitions for engineering stress, true stress, engineering strain, and true strain for loading along a single axis.  eng  engineering stress  load initial cross-sectional area  P A0 (1-1a)  true  true stress  load instantaneous cross-sectional area  P Ai (1-2a)  eng  engineering strain  change in length initial length  l f  l0 l0 (1-1b)  true  true strain  ln final length initial length  ln l f l0 (1-2b) 1.4 Under what conditions is Eq. 1-4 valid? What makes it no longer useful if those conditions are not met? Deformation and Fracture Mechanics of Engineering Materials, 5th ed. Problem Solutions p. 2/162 Draft document, Copyright R. Hertzberg, R. Vinci, J. Hertzberg 2009 Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other reproduction or translation of this work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyright Act without the permission of the copyright owner is unlawful.  true  P A0 (li / l0 )   eng (li / l0 )   eng (1 eng ) (1-4) This expression is true when volume is conserved. However, it is only useful if the crosssectional area is the same everyone on the test specimen. If this isn’t the case then the stress and strain will vary from one part of the specimen to another. 1.5 Sketch Figure 1.3, curve ‘b’ (a ductile metal). Label it with the following terms, indicating from which location on the curve each quantity can be identified or extracted: elastic region, elastic-plastic region, proportional limit, tensile strength, onset of necking, fracture stress. strain stress fracture stress elastic region elastic-plastic region proportional limit tensile strength onset of necking 1.6 On a single set of axes, sketch approximate atomic force vs. atom-separation curves like the one shown in Fig. 1.4b for tungsten at temperatures of 200, 600, and 1000 K. Pay close attention to the point x0 and the slope dF/dx for each of the curves you draw. The key features of the plot are the increasing x0 spacing with increasing temperature (i.e., with thermal expansion) and the decreasing slope associated with decreased elastic modulus. The plot is exaggerated but the trends are reasonable. F x x0 (1000 K) x0 (600 K) x0 (200 K) dF dx 200 K 600 K 1000 K Deformation and Fracture Mechanics of Engineering Materials, 5th ed. Problem Solutions p. 3/162 Draft document, Copyright R. Hertzberg, R. Vinci, J. Hertzberg 2009 Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other reproduction or translation of this work beyond that permitted by Sections 107 or 108 of the