The document discusses torsion and springs. It first discusses torsion in rotating shafts used to transmit power in industries. When a shaft twists, it induces shear stress in addition to bending and axial stresses. It then discusses different types of springs used to absorb energy through resilience. Springs can be classified based on the type of resilience (bending or torsion), construction (laminated or helical), and the nature of load carried (compression or tension). Helical springs are further classified as closely or openly coiled. Compression springs have coils that close under load while tension springs have coils that open under load.

1. SEMINAR
strength of materials

2. name : G.DINESHPIRAN.
year / sem : II/III.
section : "C".
seminar topic:TORSION & SPRINGS.
date :
submitted by subject incharge
G. DINESHPIRAN. s.karthikeyan

3. The rotating members
such as shafts are normally used to
transmit the power in industries. When
the shaft is used to transmit the power, it
is subjected to twisting moment. Due to
the twisting moment the shear stress is
induced in the shaft in addition to
bending and axial stresses.

4. The material of the shaft is uniform
throughout.
The twist along the shaft is uniform
throughout.
The cross-section of the shaft is
circular and is uniform throughout.
The shear stress induced should not
exceed the limit of proportionality.
Cross0section of the shaft which are
plane before twist remain plane after
twist remain plane after twist.
All radii which are straight before twist
remain straight after twist.

5. Spring is a mechanical
device ,which is used to absorb the
energy due to resilience. In spring, the
materials are arranged in such a way that
it will undergo the elastic deformation
when it is subjected to load. The spring
which is capable of absorbing maximum
amount of energy for the given stress, is
known to be the best spring.

6. 1. Based on the type of resilience :
a). Bending springs,
b). Torsion springs.
2. Based on the construction of spring :
a). Laminated or leaf springs,
b). Helical springs.
3. Based on the nature of the load it can
carry:
a).Compression spring,
b).Tension spring.

7. A spring which is subjected to
bending only and the resilience is also due to
bending, is known as bending spring.
Example : Leaf spring.
Torsion spring:
A spring which is subjected to
torsion or twisting moment only and the
resilience is also due to also due to torsion or
twisting moment is known as torsion springs.
Example : closely
coiled helical
spring

8.  It is the torsion
spring. It is made up of a wire coiled into
helix.
There are two types of helical spring:
a). Closely coiled helical spring,
b). Open coiled helical spring .

9. The helical spring in which
the coils close when it is subjected to axial load
and open out when the load is removed is
called compression springs.
Example : spring used in shock absorber.
Tension spring :
The helical spring in which the coils
open out when it is subjected to axial load and
closes when the load is removed is called
tension springs.
Example : spring used in spring balance.