ENGINEERING 4312:  Mechanics of Solids I


Instructor                   Dr. Seshu Adluri                     Teaching Assistants   TBA

E-mail                                      E-mail                         

Phone                         864-3800                                 Phone                        

Office Location          EN-3044                                  Office Location         

Office Hours               Monday 11:00-11:50 a.m.     Office Hours              

                                    Monday  3:00 - 3:50 p.m.                             


Communication         email



Mechanics of Solids I examines force analysis of structures and structural components, free body diagrams of structure, components and section of a component, definition of a stress at point, stress notation, complementary property of shear stress, definition of strain, normal strain, shear strain, thermal strain, mechanical properties of materials, analysis of prismatic members due to axial, bending and torsion loading, analysis of beams, shear force and bending moment diagrams, combined loads; and the transformation of stresses and strains.  


Rationale:  The subject has two primary purposes:

1.      Introducing the issues involved with deformable bodies  --their mechanics, strength, effects of applying loads, stresses, strains, deformations, deflections, etc.

2.      Introducing the basic thought processes that lead to the successful analysis of a very large class of engineering problems.  This eventually leads to the engineered design of a great many components, structures and vessels in general. 

The material covered in the present course, although not very vast, is fundamental to a large variety of further courses in the engineering program.  It is imperative that the students learn the material as thoroughly as possible since the subject is the basis for further development of many ideas later on.  All design procedures involving any kind of solids are based on the principles developed in this subject.  This used to be known as “Strength of Materials” and has a very long and distinguished history.

Continuing from the earlier concepts of forces, moments, equilibrium, freebody diagrams, etc., the course will seek to cover the theory and application of the principles, emphasizing the basic requirement of satisfying force equilibrium, compatibility of deformation, and material behaviour. The laboratory experiments give a physical introduction to the behaviour of solid elements when subjected to loads that deform them.

PREREQUISITES:                     ENGI 1010

SCHEDULE:                              LECTURE: T, Th 3:30-4:45 p.m.           Room: EN2006

                                                TUTORIAL: Mon 4:00-4:50 p.m.          Room: EN1052

CREDIT VALUE:                       3 credits


RESOURCES:                           Text book

·         Mechanics of Materials by R.C. Hibbeler, Prentice Hall, New Jersey, USA


REFERENCES:  As discussed in class from time to time

MAJOR TOPICS:                     

0. Quick Review of Earlier Concepts

1.1. Introduction: Force, Moment, Equilibrium, Free-body diagrams, etc.

Main Topics

1. Stress

1.1. Introduction

1.2. Equilibrium of a Deformable Body

1.3. Stress

1.4. Average Normal Stress in an Axially Loaded Bar

1.5. Average Shear Stress

1.6. Allowable Stress
1.7. Design of Simple Connections

2. Strain

2.1. Deformation

2.2. Strain

3. Mechanical Properties of Materials

3.1. The Tension and Compression Test

3.2. The Stress–Strain Diagram

3.3. Stress–Strain Behaviour of Ductile and Brittle Materials

3.4. Hooke's Law

3.5. Strain Energy

3.6. Poisson's Ratio

3.7. The Shear Stress–Strain Diagram

4. Axial Load

4.1. Saint-Venant's Principle

4.2. Elastic Deformation of an Axially Loaded Member

4.3. Principle of Superposition

4.4. Statically Indeterminate Axially Loaded Member

4.5. The Force Method of Analysis for Axially Loaded Members

4.6. Thermal Stress

5. Torsion

5.1. Torsional Deformation of a Circular Shaft

5.2. The Torsion Formula

5.3. Power Transmission

5.4. Angle of Twist

5.5. Statically Indeterminate Torque-Loaded Members

6. Bending

6.1. Shear and Moment Diagrams

6.2. Graphical Method for Constructing Shear and Moment Diagrams

6.3. Bending Deformation of a Straight member

6.4. The Flexure Formula

6.5. Unsymmetric Bending

6.6. Composite Beams

7. Transverse Shear

7.1. Shear in Straight Members

7.2. The Shear Formula

7.3. Shear Stresses in Beams

7.4. Shear Flow in Built-Up Members

8. Combined Loadings

8.1. Thin-Walled Pressure Vessels

8.2. State of Stress Caused by Combined Loadings

9. Stress Transformation

9.1. Plane-Stress Transformation

9.2. General Equations of Plane-Stress Transformation

9.3. Principal Stresses and Maximum In-Plane Shear Stress

9.4. Mohr's Circle—Plane Stress (introduction)

10. Strain Transformation

10.1. Plane Strain

10.2. General Equations of Plane-Strain Transformation (intro’)

The topics above may be supplemented with other topics from the textbook or additional information. All topics that are covered will be part of the examination. 

Comprehensive examples will be discussed primarily during tutorials. During tutorials, the students may be required to solve the problems in class to gain practice.  Please note that prewritten solutions may or may not be available for the assignments.  However, the tutorial immediately following the due date for assignment is allotted for discussing the relevant solutions.  At that time, if the students ask for it, the problems can be discussed and may even be solved in class.  If the students do not raise their need for discussion of the problems, the time will be spent on solving other examples.  The same policy holds for midterm exams and quizzes, if any.

The students are expected to solve the assignment problems by themselves in order to reinforce the class instruction.  Please refer to copying policy of the University if there is any doubt.  Help with the assignment problems can be sought during contact hours and/or tutorial time. 



Upon successful completion of this course, the student needs to demonstrate the following:

1.     Identify and draw freebody diagrams and bending moment & shear force diagrams of components.

2.     Have a basic idea of stresses, strains and material behaviour.

3.     Analyze stresses and strains in simple structures and components when subject to axial loads, torsion, bending, shear, etc. 

4.     Calculate internal forces of statically determinate axial load components and torsional shafts.

5.     Calculate the effects of combined loads on components including simple pressure vessels.

6.     Understanding of multiaxial stress behavior and construct Mohr’s circle for 2-D stresses.

7.     Communicate experimental data, analysis and conclusions in a clear, professional manner.



                                                Approximate Dates

Assignments                  10%                            Assignments are due one week from announcement unless otherwise stated

Labs                               5%                              As announced in class

Midterm 1                    25%                            June 03           

Midterm 2                    25%                            July 18 (better of the two midterms will be considered for grade)  

Final exam                    60%                            TBA


WARNING:  If the students are unable to draw proper Free Body Diagrams, Bending Moment and Shear Force Diagrams, the relevant questions will be marked zero even if the rest of the solution is partly or wholly correct.  The same applies for using and clearly stating the correct units in any given problem.  If the student fails in this, the relevant questions will be marked as zero.

Exam policy: The formula sheet is as per the announcement in the class.  All or a subset of the preannounced formula sheet will be provided in the exam.  No extra text or notes are permitted in the exam.  IPODS, Blackberries, MP3 players, or other electronic storage/retrieval devices are not permitted in the exam.  Please see the appropriate guidelines from the University regarding such matters.  Unauthorized use of the above aids or devices during quizzes, tests and examinations will be considered as an academic offence. 



There will be four laboratory exercises. Each experiment will be set up in the Structures Lab Room EN 1033. Each group will arrange with the Technician to schedule their use of the equipment. 


Students are expected to demonstrate awareness of, and personal accountability for, safe laboratory conduct.  Appropriate personal protective equipment (PPE) must be worn (e.g. steel-toed shoes, safety glasses, etc.) and safe work practices must be followed as indicated for individual laboratories, materials and equipment.  Students will immediately report any concerns regarding safety to the teaching assistant, staff technologist, and professor. 

Lab handouts:  Lab-general, Lab1, Lab2, Lab4, Lab3

The lab handouts are for general instructions and explanations only.  Students are must not simply cut and paste material from the handouts.  Students must write the report in their own words.  All explanations, calculations, graphs, etc., must be independently done without copying either from the handouts or from another group (present or past). 


Calculator Policy: Only simple scientific calculators are permitted in all tests and examinations. Programmable calculators with text storage and graphics capabilities, as well as other aids are NOT allowed.



Students are expected to conduct themselves in all aspects of the course at the highest level of academic integrity. Any student found to commit academic misconduct will be dealt with according to the Faculty and University practices. More information is available at


Students are encouraged to consult the Faculty of Engineering and Applied Science Student Code of Conduct at and Memorial University’s Code of Student Conduct at




Students who require physical or academic accommodations are encouraged to speak privately to the instructor so that appropriate arrangements can be made to ensure your full participation in the course.  All conversations will remain confidential.


The university experience is enriched by the diversity of viewpoints, values, and backgrounds that each class participant possesses.  In order for this course to encourage as much insightful and comprehensive discussion among class participants as possible, there is an expectation that dialogue will be collegial and respectful across disciplinary, cultural, and personal boundaries.


STUDENT ASSISTANCE:  Student Affairs and Services offers help and support in a variety of areas, both academic and personal.  More information can be found at













Examples  and  PPT files:


Introduction,  Stress and Strain, example1,


Axial loads, Examples: ex1, ex2. ex3, ex4, ex5, ex6, ex7

Torsion1, Torsion2, Examples: ex1, ex2, ex3, ex4, ex5, ex6


Review of Moment of Inertia,  Bending1, Bending2, Bending3, ex1 to ex7, 


Shear stresses, Shear Examples


Combined Loads, Examples, Pressure Vessels


Stress Transformation, Examples



Exam Formula Sheet


Sample Midterm exam solution,


Sample final exam, Answers only