Applied Strength of Materials

Robert L. Mott is professor emeritus of engineering technology at the University of Dayton. He is a member of ASEE, SME, and ASME. He is a Fellow of ASEE and a recipient of the ASEE James H. McGraw Award, Frederick J. Berger Award, and the Archie Higdon Distinguished Educator Award (From Applied Mechanics Division). He is a recipient of the SME Education Award. He holds the Bachelor of Mechanical Engineering degree from General Motors Institute (now Kettering University) and the Master of Science in Mechanical Engineering from Purdue University. His industry experience includes General Motors Corporation, consulting for several companies, and serving as an expert witness on numerous legal cases. He is the author of three textbooks: Applied Fluid Mechanics 7th ed. (co-authored with Joseph A. Untener) and Machine Elements in Mechanical Design 6th ed., published by Pearson/Prentice-Hall; Applied Strength of Materials 6th ed. (co-authored with Joseph A. Untener) with CRC Press. Joseph A. Untener, P.E. is a professor of engineering technology at the University of Dayton. He is a member of ASEE, SME, and ASME. He holds the Bachelor of Mechanical Engineering degree from General Motors Institute (now Kettering University) and the Master of Science in Industrial Administration from Purdue University. He has worked on the design and implementation of manufacturing equipment at General Motors, and served as an engineering consultant for many other companies. He teaches courses in Mechanical Engineering Technology at UD. He has co-authored two textbooks with Robert L. Mott: Applied Fluid Mechanics 7th ed. published by Pearson/Prentice-Hall, and Applied Strength of Materials 6th ed. with CRC Press.

Preface


Basic Concepts in Strength of Materials


The Big Picture


Objective of This Book – To Ensure Safety


Objectives of This Chapter


Problem-solving Procedure


Basic Unit Systems


Relationship Among Mass, Force, and Weight


The Concept of Stress


Direct Normal Stress


Stress Elements for Direct Normal Stresses


The Concept of Strain


Direct Shear Stress


Stress Element for Shear Stresses


Preferred Sizes and Standard Shapes


Experimental and Computational Stress





Design Properties of Materials


The Big Picture


Objectives of This Chapter


Design Properties of Materials


Steel


Cast Iron


Aluminum


Copper, Brass, and Bronze


Zinc, Magnesium, Titanium, and Nickel-Based Alloys


Nonmetals in Engineering Design


Wood


Concrete


Plastics


Composites


Materials Selection





Direct Stress, Deformation, and Design


The Big Picture and Activity


Objectives of this Chapter


Design of Members under Direct Tension or Compression


Design Normal Stresses


Design Factor


Design Approaches and Guidelines for Design Factors


Methods of Computing Design Stress


Elastic Deformation in Tension and Compression Members


Deformation Due to Temperature Changes


Thermal Stress


Members Made of More Than One Material


Stress Concentration Factors for Direct Axial Stresses


Bearing Stress


Design Bearing Stress





Design for Direct Shear, Torsional Shear, and Torsional Deformation


The Big Picture


Objectives of This Chapter


Design for Direct Shear Stress


Torque, Power, and Rotational Speed


Torsional Shear Stress in Members with Circular Cross Sections


Development of the Torsional Shear Stress Formula


Polar Moment of Inertia for Solid Circular Bars


Torsional Shear Stress and Polar Moment of Inertia for Hollow Circular Bars


Design of Circular Members under Torsion


Comparison of Solid and Hollow Circular Members


Stress Concentrations in Torsionally Loaded Members


Twisting – Elastic Torsional Deformation


Torsion in Noncircular Sections





Shearing Forces and Bending Moments in Beams


The Big Picture


Objectives of this Chapter


Beam Loading, Supports, and Types of Beams


Reactions at Supports


Shearing Forces and Bending Moments for Concentrated Loads


Guidelines for Drawing Beam Diagrams for Concentrated Loads


Shearing Forces and Bending Moments for Distributed Loads


General Shapes Found in Bending Moment Diagrams


Shearing Forces and Bending Moments for Cantilever Beams


Beams with Linearly Varying Distributed Loads


Free-Body Diagrams of Parts of Structures


Mathematical Analysis of Beam Diagrams


Continuous Beams – Theorem of Three Moments





　


Centroids and Moments of Inertia of Areas


The Big Picture


Objectives of This Chapter


The Concept of Centroid – Simple Shapes


Centroid of Complex Shapes


The Concept of Moment of Inertia


Moment of Inertia for Composite Shapes Whose Parts have the Same Centroidal Axis


Moment of Inertia for Composite Shapes – General Case – Use of the Parallel Axis Theorem


Mathematical Definition of Moment of Inertia


Composite Sections Made from Commercially Available Shapes


Moment of Inertia for Shapes with all Rectangular Parts


Radius of Gyration


Section Modulus





　


Stress Due to Bending


The Big Picture


Objectives of This Chapter


The Flexure Formula


Conditions on the Use of the Flexure Formula


Stress Distribution on a Cross Section of a Beam


Derivation of the Flexure Formula


Applications – Beam Analysis


Applications – Beam Design and Design Stresses


Section Modulus and Design Procedures


Stress Concentrations


Flexural Center or Shear Center


Preferred Shapes for Beam Cross Sections


Design of Beams to be Made from Composite Materials





Shearing Stresses in Beams


The Big Picture


Objectives of this Chapter


Importance of Shearing Stresses in Beams


The General Shear Formula


Distribution of Shearing Stress in Beams


Development of the General Shear Formula


Special Shear Formulas


Design for Shear


Shear Flow





Deflection of Beams


The Big Picture


Objectives of this Chapter


The Need for Considering Beam Deflections


General Principles and Definitions of Terms


Beam Deflections Using the Formula Method


Comparison of the Manner of Support for Beams


Superposition Using Deflection Formulas


Successive Integration Method


Moment-Area Method





Combined Stresses


The Big Picture


Objectives of this Chapter


The Stress Element


Stress Distribution Created by Basic Stresses


Creating the Initial Stress Element


Combined Normal Stresses


Combined Normal and Shear Stresses


Equations for Stresses in Any Direction


Maximum Stresses


Mohr’s Circle for Stress


Stress Condition on Selected Planes


Special Case in which Both Principal Stresses have the Same Sign


Use of Strain-Gage Rosettes to Determine Principal Stress Columns





Columns


The Big Picture


Objectives of this Chapter


Slenderness Ratio


Transition Slenderness Ratio


The Euler Formula for Long Columns


The J. B. Johnson Formula for Short Columns


Summary – Buckling Formulas


Design Factors and Allowable Load


Summary – Method of Analyzing Columns


Column Analysis Spreadsheet


Efficient Shapes for Columns


Specifications of the AISC


Specifications of the Aluminum Association


Non-Centrally Loaded Columns





Pressure Vessels


The Big Picture


Objectives of this Chapter


Distinction Between Thin-Walled and Thick-Walled Pressure Vessels


Thin-Walled Spheres


Thin-Walled Cylinders


Thick-Walled Cylinders and Spheres


Analysis and Design Procedures for Pressure Vessels


Spreadsheet Aid for Analyzing Thick-Walled Spheres and Cylinders


Shearing Stress in Cylinders and Spheres


Other Design Considerations for Pressure Vessels


Composite Pressure Vessels





Connections


The Big Picture


Objectives of this Chapter


Modes of Failure for Bolted Joints


Design of Bolted Connections


Riveted Joints


Eccentrically Loaded Riveted and Bolted Joints


Welded Joints with Concentric Loads


Appendix


Answers to Selected Problems