Table of Contents
Why is a circular cross section the most efficient shape for resisting torsion?
When bending is required, it is important that the shape be an I-beam like shape. When the direction of the bending moment is not known, a hollow circular cross section is an ideal shape for the I-Beam Principle, because it has an equally large area moment of inertia about any cross-sectional axis.
What shape is most resistant to torsion?
Circular closed shapes, such as round HSS and steel pipe, are most efficient for resisting torsional loading. Other closed shapes, such as square and rectangular HSS, also provide considerably better resistance to torsion than open shapes, such as W-shapes and channels.
Why the circular shafts are preferred for the power transmissions?
Generally for power transmission, circular shafts are used because there is uniform stress distribution along any radius of the shaft. Plane sections of shaft remain plane after the application of twisting moment, as a result there is no distortion in the sections of shafts and change in volume of the shaft is zero.
Why hollow circular section is best in torsion?
Hollow circular section is best in torsion as the polar moment of inertia is highest for hollow circular section (for same amount of material). I-section is best suited for transverse loads. I- section can take bending load as well as shear load.
Which type of cross section is best at resisting twisting?
Box sections
Note: Box sections are best for resisting torsion. Figure 4-12.
Which section is best in bending?
I – section is best suited for transverse loads I- section can take bending load as well as shear load. It can take up to 80\% of bending load which is resisted by flanges and 90 \% of shear load is resisted by web.
How it is useful in torsional analysis?
In general a torsional analysis is necessary for reciprocating, screw, and centrifugal compressors and should include: preparing an appropriate mass elastic model; accounting for all gear speed ratio effects (if applicable) on stiffness, inertia, torque, and stress; determining the system critical speeds; evaluating …
What are torsional forces?
A torsion force is a load that is a applied to a material through torque. The torque that is applied creates a shear stress. If a torsion force is large enough, it can cause a material to undergo a twisting motion during elastic and plastic deformation.
Why is hollow circular shaft preferred over solid circular shaft?
The stiffness of the hollow shaft is more than the solid shaft with the same weight. In the hollow shaft, the material at the centre is removed and spread at large radius. Therefore, hollow shafts are stronger than solid shaft having the same weight.
When a shaft is subjected to torsion?
When a shaft is subjected to a torque or twisting a shearing stress is produced in the shaft. The shear stress varies from zero in the axis to a maximum at the outside surface of the shaft. the “Polar Moment of Inertia of an Area” is a measure of a shaft’s ability to resist torsion.
Which of the following steel section is most ideal for resisting torsion?
Note: Box sections are best for resisting torsion.
Which section is a good resistant to both bending and torsion?
It is recognized that the hollow cylindrical geometry of human long bone in upper limbs and lower limbs is designed to resist bending and torsion.