Mechanical Engineering - Machine Design - Discussion
Discussion Forum : Machine Design - Section 1 (Q.No. 47)
47.
Two shafts A and B under pure torsion are of identical length and identical weight and are made of the same material. The shaft A is solid and the shaft B is hollow. We can say that
Discussion:
16 comments Page 1 of 2.
Sameh Bazan said:
9 years ago
Please note that the two shafts have same length and weight, then you can conclude that the outer DIA of the Hollow Section will be bigger than Solid rod, the greater the DIA the Greater the Torsion Resistance (Power Transmitted).
Another Aspect the Polar moment of inertia, which is inversely probational with the Shear stress.
τ = Tp/J.
τ : Shear Stress.
T : Transmitted Torque.
P : Radial Distance to Shaft Center.
J : Polar moment of inertia.
Another Aspect the Polar moment of inertia, which is inversely probational with the Shear stress.
τ = Tp/J.
τ : Shear Stress.
T : Transmitted Torque.
P : Radial Distance to Shaft Center.
J : Polar moment of inertia.
PRANAB JYOTI DUTTA said:
8 years ago
From the torsion equation, we may answer this question. For identical length and weight the polar moment of inertia for the hollow shaft is less than that of a solid shaft, as a result, the shear stress for the hollow shaft is more than the solid shaft. That means the resisting force to torsion is more in a case of tthe hollow shaft, hence it is better compared to the solid shaft.
Balasaheb said:
5 years ago
The weight & Length of the shafts are identical means the hollow shaft diameter naturally going to increase hence the Hollo shaft will have the more torsional strength. Hence hollow shaft with the same weight will give move strength.
Turkish mechanical engineer said:
1 decade ago
If they have same weight and same length that means they have same area of cross section. But shaft with hollow is better because it has more J (polar second moments of area) which is important on shearing load.
Shalabh Suradhaniwar said:
1 decade ago
Shear Stress inversely proportional to J.
J in hollow = Pi*(Do-Di)4/32.
J less, so hollow can bear more Torsion.
J in solid = Pi*(Do)4/32.
J more, so solid can bear less Torsion.
J in hollow = Pi*(Do-Di)4/32.
J less, so hollow can bear more Torsion.
J in solid = Pi*(Do)4/32.
J more, so solid can bear less Torsion.
Hardik patel said:
1 decade ago
As the area of resisting the load in hollow shaft will reduce and in solid shaft will very high so pressure acting upon the solid shaft is less as compared to hollow so it is safe.
Muttinagouda raviraj said:
1 decade ago
A is better than B. Because as the area of cross section increases stress acting on material can distributed stress to entire area. And it has ability to resist the applied load.
Anjana said:
1 decade ago
In qn base for comparison is not given, for cost point of view hollow is best, but in case of maximum load carrying capacity and resist the torsion the solid shaft is better.
YUGAL said:
8 years ago
If two shafts of same weight and cross section then hollow shaft having more stength. If two shaft of same diameter then solid shaft having more strength and stiffness.
Saikumar said:
1 decade ago
Natural frequency is higher for hollow shaft with same weight. Strength of hollow shaft is higher with same weight. Stiffness is more for hollow shaft with same.
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