Untitled Essay Research Paper TABLE OF CONTENTSINTRODUCTION

Untitled Essay, Research Paper

TABLE OF CONTENTS

INTRODUCTION…………………………………………………………………………………….1

Chapter

I. General

Principles………………………………………………………………………2

I. Systems of

Force………………………………………………………………………..4

II.

Stress………………………………………………………………………………………6

III. Properties of

Material…………………………………………………………….7

IV. Bolted and Welded

Joints………………………………………………………..10

V. Beams — A Practical

Application……………………………………………..13

VI. Beam

Design………………………………………………………………………..17

VII. Torsional Loading: Shafts, Couplings, and

Keys…………………..19

VIII.

Conclusion……………………………………………………………………….20

BIBLIOGRAPHY…………………………………………………………………………………21

INTRODUCTION Mechanics is the physical science concerned with the dynamic behavior

of bodies that are acted on by mechanical disturbances. Since such behavior is involved in

virtually all the situations that confront an engineer, mechanics lie at the core of much

engineering analysis. In fact, no physical science plays a greater role in engineering

than does mechanics, and it is the oldest of all physical sciences. The writings of

Archimedes covering bouyancy and the lever were recorded before 200 B.C. Our modern

knowledge of gravity and motion was established by Isaac Newton (1642-1727).

Mechanics can be divided into two parts: (1) Statics, which relate to

bodies at rest, and (2) dynamics, which deal with bodies in motion. In this paper we will

explore the static dimension of mechanics and discuss the various types of force on an

object and the different strength of materials.

The term strength of materials refers to the ability of the individual

parts of a machine or structure to resist loads. It also permits the selection of

materials and the determination of dimensions to ensure the sufficient strength of the

various parts.

General Principles Before we can venture to explain statics, one must have a firm grasp on

classical mechanics. This is the study of Newton’s laws and their extensions.

Newton’s three laws were originally stated as follows:

1. Every body continues in its state of rest, or of uniform motion in a

straight line, unless it is compelled to change that state by

forces impressed on it.

2. The change of motion is proportional to the motive force impressed

and is made in the direction in which that

force is impressed.

3. To every action there is always opposed an equal reaction; or the

mutual actions of two bodies on each other

are equal and direct to contrary parts.

Newton’s law of gravitational attraction pertains to celestrial

bodies or any object onto which gravity is a force and states: “Two particles will be

attracted toward each other along their connecting line with a force whose magnitude is

directly proportional to the product of the masses and inversely proportional to the

distance squared between the particles.

When one of the two objects is the earth and the other object is near

the surface of the earth (where r is about 6400 km) / is essentially constant, then the

attraction law becomes f = mg.

Another essential law to consider is the Parallelogram Law. Stevinius

(1548-1620) was the first to demonstrate that forces could be combined by representing

them by arrows to some suitable scale, and then forming a parallelogram in which the

diagonal represents the sum of the two forces. All vectors must combine in this manner.

When solving static problems as represented as a triangle of force,

three common theorems are as follows:

1. Pythagorean theorem. In any right triangle, the square of the

hypotenuse is equal to the sum of the

squares of the two legs:

=

2. Law of sines. In any triangle, the sides are to each other as the

sines of the opposite angle:

3. Law of cosines. In any triangle, the square of any side is equal to

the sum of the squares of the other two

sides minus twice the product of the sides and the

cosine of their included angle: = – 2ab cos C

By possessing an understanding of Newton’s Laws, following these

three laws of graphical solutions, and understanding vector algebra you can solve most

engineering static problems.Systems of Force Systems of force acting on objects in equilibrium can be classified as

either concurrent or nonconcurrent and as either coplanar or noncoplanar. This gives us

four general categories of systems.

The first category, concurrent-coplanar forces occur when the lines of

action of all forces lie in the same plane and pass through a common point. Figure 1

illustrates a concurrent-coplanar force in such that F1, F2, and W all lie in the same

plane (the paper) and all their lines of action have point O in common. To determine the

resultant of concurrent force systems, you can use the Pythagorean theorem, the law of

Внимание, отключите Adblock

Вы посетили наш сайт со включенным блокировщиком рекламы!
Ссылка для скачивания станет доступной сразу после отключения Adblock!

Скачать