Strength of Material_Chapter.01_Basics

Chapter – 01

Basic Concept

01. Introduction:

The subject deals with study of material on basis of strength, mechanical properties and behavior of structural member or material under externally applied load.

02. Loads:

                   It is externally applied force or any moment on structure, member or substance (body) is called “Load”. There are different types of loads, they are as follows.

a)     Dead Load- It is self-weight of structure or substance or member (No external application of load)

b)    Live Load- It is present force acting on body or structure. It is a periodic type of load.

c)     Wind Load- Application of load or force due wind flowing.

d)    Impact Load- It is load suddenly acting on substance or structure or body.

e)     Seismic Load- Continue type of load acting on body, structure for short period of time. Intensity of load is    more or less over time period.

f)      Snow Load- It is down-word force acting on body, member or structure by accumulated weight of snow or ice.

           Above mentioned loads are considered in design of structure.

03. Types of Loads:

There are three types of loads in design consideration..

a)     Tensile Force (or Load):

The force which is acting away from point of application called “Tensile Force or Load”. It is also called as “Pulling force or Pull“.

                                           

                   Figure: 3(a)

b)     Compression Force (or Load):

It is the force which is action towards its point of application called “Compressive force or load”. It is also called as “Pushing or Push".

                                             

                                                                     Figure: 3(b)

c)      Shear Force (or Load):

The force which is acting parallel or tangential to plain is called “Shear force or load“.

                                          

                                                                                                    Figure: 3(c)

04. Effects of Loads:

A) Member under tension- 

            It is also called as tie member, which generate tensile stress and strain.

            B) Member under compression-

            This type of member also called “Column or Strut” and create compressive stress or strain.

            C) Member under shear-

            This type of member produce shear stress or strain. Pins, rivets & bolts are the some example.

D) Due to force, the member goes under bending which produce bending stress and strain. A beam under bending is called flexural member.

 E) Force also creates twist, member on which it acts produce the torsional stress and strain. The member under twist is called member in torsion.  E.g. Shafts etc.