# What are assumptions in torsion theory?

Q.  Which of the following assumptions are made in torsion theory?
- Published on 23 Sep 15

a. Shaft is perfectly straight
b. Material of the shaft is heterogeneous
c. Twist cannot be uniform along the length of the shaft
d. All of the above

ANSWER: Shaft is perfectly straight

#### Discussion

• ambrown   -Posted on 15 Oct 18
Great! kip up pliz...
• Pavan   -Posted on 09 Jan 18
Really helpfull
• sachin   -Posted on 12 Dec 17
thank you for your answer and I want some more notes for aeronautical engineering
• aman raj   -Posted on 29 May 17
the material used should be homogeneous. .. not be heterogeneous.
• Sravanthi   -Posted on 25 Nov 15
Different assumptions made in torsion theory are as follows:

1) Shaft must be straight and should have uniform cross-section.

2) The shear stress induced in shaft should not exceed the elastic limit.

3) Twist along the shaft is uniform.

4) Twisting has no effect on circularity of shaft.

- The relation ( T/J = Gθ/L = τ/ R) is called as torsion formula.

Here,

T is the twisting moment
J is the polar moment of inertia
G is the modulus of rigidity
θ is the angle of twist (radian)
τ is the shear stress
R is the shaft radius

## ➨ Post your comment / Share knowledge

Enter the code shown above:

(Note: If you cannot read the numbers in the above image, reload the page to generate a new one.)