3.11 | Fall 1999 | Graduate

Mechanics of Materials

Modules

The .exe files found in this section are executable programs.

In 1996, the MIT subject 3.11 Mechanics of Materials in the Department of Materials Science and Engineering began using an experimental new textbook approach by Roylance (Mechanics of Materials, Wiley ISBN 0-471-59399-0), written with a strongly increased emphasis on the materials aspects of the subject. It also included several topics such as finite element methods, fracture mechanics, and statistics that are not included in most traditional Mechanics of Materials texts. These nontraditional aspects were designed to fit the curriculum in Materials Science and Engineering, but do not always fit the needs of instructors in other departments and schools.

One approach to increasing the flexibility and adaptability of this materials-oriented text is to make discrete and coherent portions of it available as stand-alone modules. Instructors could then pick and choose among topics, and assemble a subject offering in whatever way they choose. It would also be possible for instructors of specialty engineering subjects, for instance bridge or aircraft design, to add modules on mechanics of materials aimed at their own needs.

A series of such modules are now being developed under a National Science Foundation Course, Curriculum and Laboratory Improvement (CCLI) grant aimed at strengthening the links in the engineering curriculum between materials and mechanics. The module development began July 15, 1999 and is planned for completion by June 30, 2001.

The modules are pdf versions of LaTeX text files, and require an Acrobat-capable web browser for viewing or printing. The modules are numbered sequentially and ordered logically as in the Roylance text, with those still under construction indicated by trailing asterisks. Each module is intended to be capable of standing alone, so that it will usually be unnecessary to work through other modules in order to use any particular one. However, it is sometimes necessary to refer to earlier modules in order to avoid excessive repetition.

MODULE DESCRIPTION TOPICS
Tensile Response of Materials The modules in this section will outline some of the basic concepts of materials mechanical response by restricting the geometry to a case of simple uniaxial tension. Many of the atomistic and mechanistic concepts in our materials-oriented approach to solid mechanics can be introduced in this way, without the mathematical and conceptual complications that more realistic gemoetries entail. Subsequent modules will extend these concepts to geometrically more complicated situations, and introduce gradually the mathematical language used by the literature of the field to describe them. Introduction to Elastic Response (PDF)

Atomistics of Elasticity (PDF)

Introduction to Composites (PDF)

Stress-Strain Curves (PDF)

Simple Tensile and Shear Structures The modules in this section will outline some of the basic concepts of materials mechanical response by restricting the geometry to a case of simple uniaxial tension. Many of the atomistic and mechanistic concepts in our materials-oriented approach to solid mechanics can be introduced in this way, without the mathematical and conceptual complications that more realistic gemoetries entail. Subsequent modules will extend these concepts to geometrically more complicated situations, and introduce gradually the mathematical language used by the literature of the field to describe them. Trusses (PDF)

Pressure Vessels (PDF)

Shear and Torsion (PDF)

General Concepts ofStress and Strain In extending the direct method of stress analysis presented in previous modules to geometrically more complex structures, it will be convenient to have available somewhat more general mathematical statements of the kinematic, equilibrium, and constitutive equations; this is the objective of the present chapter. These equations also form the basis for more theoretical methods in stress analysis, as well as for numerical approaches such as the finite element method. We will also seek to introduce some of the notational schemes used widely in the technical literature for such entities as stress and strain. Depending on the specific application, both index and matrix notations can be very convenient; these are described in a separate module. Kinematics (PDF)

Equilibrium (PDF)

Tensor Transformations (PDF)

Constitutive Relations (PDF)

Bending This modules in this section will develop relations between stresses, deflections, and applied loads for beams and flat plates subjected to bending loads. This will be done using the direct method employed in Module 7 for circular shafts in torsion. However, bending problems have a higher order of dimensionality than twisted shafts, and it will be convenient to use the more general formulations developed in Modules 8 - 11. In particular, pseudovector-matrix notation will allow easy extension of beam concepts to flat plates. Shear and Bending Moment Diagrams (PDF)

Stresses in Beams (PDF)

Beam Displacements (PDF)

Laminated Composite Plates (PDF)

General Stress Analysis The results presented in earlier modules for trusses, beams, and other simple shapes provide much of the information needed in design of load-bearing structures. However, materials and structural engineers routinely need to estimate stresses and deflections in geometrically more irregular articles. This is the function of stress analysis, by which we mean the collection of theoretical and experimental techniques that goes beyond the direct-analysis approach used up to now. This is a career field in its own right, and these modules will limit themselves to outlining only a few of its principal features. Closed-Form Solutions (PDF)

Experimental Solutions (PDF)

Finite Element Analysis (PDF)

Linear Viscoelasticity (PDF)

Yield and Fracture   Yield and Plastic Flow (PDF)

Dislocation Basis of Yield and Creep (PDF)

Statistics of Fracture (PDF)

Introduction to Fracture Mechanics (PDF)

Fatigue (PDF)

Appendices   Material Properties (PDF)

Matrix and Index Notation (PDF)

List of Symbols (PDF)

Unit Conversion Factors (PDF)

Software   Mohr's circle (Java applet)

strs3d - Stress Transformations

plate - Laminated Plates

Course Info

As Taught In
Fall 1999
Level
Learning Resource Types
Simulations
Online Textbook
Problem Sets