CHAPTER 7 SOLID MATERIALS Joseph Datsko Professor Emeritus of Mechanical Engineering The University of Michigan Ann Arbor, Michigan STRUCTURE OF SOLIDS / ATOMIC BONDING FORCES / ATOMIC STRUCTURES / CRYSTAL IMPERFECTIONS / SLIP IN CRYSTALLINE SOLIDS / MECHANICAL STRENGTH / MECHANICAL PROPERTIES AND TESTS / HARDNESS / THE TENSILE TEST / TENSILE PROPERTIES / STRENGTH, STRESS, AND STRAIN RELATIONS / IMPACT STRENGTH / CREEP STRENGTH / MECHANICAL-PROPERTY DATA / NUMBERING SYSTEMS / REFERENCES. | CHAPTER 7 SOLID MATERIALS Joseph Datsko Professor Emeritus of Mechanical Engineering The University of Michigan Ann Arbor Michigan STRUCTURE OF SOLIDS I ATOMIC BONDING FORCES ATOMIC STRUCTURES CRYSTAL IMPERFECTIONS I SLIP IN CRYSTALLINE SOLIDS MECHANICAL STRENGTH MECHANICAL PROPERTIES AND TESTS HARDNESS THE TENSILE TEST TENSILE PROPERTIES STRENGTH STRESS AND STRAIN RELATIONS I IMPACT STRENGTH CREEP STRENGTH I MECHANICAL-PROPERTY DATA NUMBERING SYSTEMS I REFERENCES This chapter summarizes the structure of solids including atomic bonding forces atomic structures crystal imperfections slip and mechanical strength. The section on mechanical properties and tests discusses all the hardness tests and includes a detailed explanation of the tensile test and tensile properties. The section on strength stress and strain relations includes many new relationships that have been developed during the past two decades and are not found in other handbooks. The mechanical property data presented in this section are in a new format that is well suited for use in computer-aided-engineering CAE applications. STRUCTURE OF SOLIDS A study of the mechanical properties of materials must begin with an understanding of the structure of solid materials. In this context structure refers to the atomistic and crystalline patterns of which the solid material is composed. The definitions of the mechanical properties given in the following sections are on the basis of the crystalline structure of material. For example strength and hardness is defined as the ability of the material to resist slip along its crystallographic planes. Thus in order to increase the strength of a material something must be done to it which will make STANDARD HANDBOOK OF MACHINE DESIGN slip more difficult to initiate. The following sections will explain the manner in .