Bending And Torsion Flashcards
What is torsion?
Torsion is the twisting of objects such as rods or shafts due to an applied torque.
What is warping in torsion?
Warping is the deformation of a twisted object, typically visible in rods with non-circular cross-sections. For circular cross-sections, warping is not observed as the shape remains circular during twisting.
When does warping become significant in a rod under torsion?
Warping becomes significant in rods with non-circular cross-sections because these shapes tend to distort during twisting.
How is torsional shear stress generated in a rod?
Torsional shear stress is generated when a torque is applied to the front face of a circular rod, with an opposing reaction torque acting at the fixed rear face.
What is the distribution of torsional shear stress over the cross-section of a rod?
Torsional shear stress varies from zero at the center to a maximum at the surface and acts perpendicular to the axis of the torque (along the radius).
How does torsional shear stress distribution differ from the stress induced by axial loads?
While axial loads generate a uniform shear stress across the entire cross-section, torsional shear stress increases from the center toward the surface.
What are some key assumptions for deriving the torsion equation?
The material is homogeneous and follows Hooke’s law.
Shear stress is proportional to shear strain.
The cross-sectional area remains plane.
The circular section stays circular after twisting.
The stress does not exceed the elastic limit.
What is a beam, and what types of loads can it experience?
A beam is a structural member used to support loads and can experience normal, shear, and bending loads.
What is pure bending?
Pure bending occurs when a beam is subjected to a constant bending moment, without any axial, shear, or torsional forces.
How does the neutral axis behave during bending?
The neutral axis is the surface in the beam where fibers experience neither compression nor tension, and it bends without deformation.
What assumptions are made for deriving the pure bending equation?
The beam is initially straight and unstressed.
It is made of homogeneous and isotropic material.
Loading is perpendicular to the longitudinal axis and within the elastic limit.
Plane cross-sections remain plane after bending.
