Home | | **Strength of Materials I** | | **Strength of Materials for Mechanical Engineers** | Important Answers: Torsion

Mechanical - Strength of Materials - Torsion

**TORSION**

**1. ****What
are the assumptions made in torsion equation?**

The material of
the shaft is
homogeneous, per

Twist is uniform along the
length of the shaft and

The stress does not exceed
the limit of proportionality

**2. Write down the expression for power
transmitted by a shaft.**

Power, P = 2пNT/ 60

Where,

T –Torque in kN.m

N –Speed in r.p.m.

P –Power in Kw

**3. Define polar modulus. **

It is the ratio between
polar moment of inertia and radius of the shaft.

**4. State the differences between closed
and open coil helical springs.**

**Closed coiled helical springs**

Adjacent coils are very
close to each other

It can carry only tensile
loads .

Helix angle is negligible

**Open coiled helical springs**

Large gap between adjacent
coils

It can carry Both tensile
and Compression loads.

Helix angle is
considerable

**5.Find
the torque which a shaft of 50mm diameter can transmit safely, if the allowable
shear stress in 75 N/mm²?**

T = п/ 16 x fsx d3

T = п/ 16 x 75 x (50)3

T = 1.840 kN.m

6. What is mean by stiffness?

The stiffness of the spring is defined as the load
required to product unit deflection.

**7.Classify
the types of springs.**

Torsion spring and

Bending spring

**8.What
is meant by spring?**

Spring is a device which is used to absorb energy by
taking very large change in its form without permanent deformation and then
release the same when it is required.

**9.Define
torsion.**

When a pair of forces of equal magnitude but
opposite in direction acting on body, it tends to twist the body. It is known
as twisting moment or simply as torque.

**10.what
is meant by torsion spring?**

A
spring, which is subjected to torsion or twisting moment only is known as
torsion spring.

**11. What is the ratio of
maximum shear stress to the average shear stress in the case of solid circular
section?**

Q_{max} is 4/3 times the Q_{avg}.

**12. What is the shear stress distribution value of Flange
portion of the I-section?**

Where, D- depth

y- Distance from neutral axis

**13. Where the shear stress is max for Triangular section?**

In the case of triangular
section, the shear stress is not max at N A. The shear stress is max at a
height of h/2

**14. Define: Mohr’sTheorem for slope**

The change of slope
between two points of a loaded beam is equal to the area of BMD between two
points divided by EI.

**15. Define: Mohr’sTheorem for deflection**

The deflection of a point with respect
to tangent at second point is equal to the first moment of area of BMD between
two points about the first point divided by EI.

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail

**Related Topics **

Copyright © 2018-2020 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.