JNTU B.Tech II MECHANICS OF SOLIDS Previous Question Paper (November/December - 2018 - R13)

Define the principle of superposition. What is its utility?

State Hooke's law. Sketch the stress-strain diagram for a ductile material like mild steel tested under tension upto destruction, marketing the salient points on it.

Bring out the difference between statically determinate beam and statically indeterminate beam?

What is the relation between shear force and loading, bending moment and shear force in a beam?

Define moment of resistance of a beam?

Sketch the bending stress as well as shear stress distribution for a beam of rectangular cross section.

What do you mean by principal plane and principal stress?

Define the term obliquity and how it is determined?

Distinguish between thin cyclinder and thick cylinder and what are the applications?

State the assumptions for shear stress in a circular shaft subjected to torsion.

Derive an expression between modulus of elasticity and modulus of rigidity.

The extension in a rectangular steel bar of length 800 mm and of thickness 20 mm to be 0.25 mm. The bar tapers uniformly in width from 80 mm to 40 mm. If E for the bar is 2×10⁵ N/mm², determine the axial tensile load on the bar.

What is the procedure of finding thermal stresses in a composite bar?

A bar of 15 mm diameter gets stretched by 4 mm under a steady load of 8000 N. What stress would be produced in the same bar by a weight of 800 N, which falls vertically through a distance of 10 cm on to a rigid collar attached at its end? The bar is initially unstressed. Take E = 2 × 10⁵ N/mm²

What do you mean by point of contra flexure? Is the point of contra flexure and point of inflexion different?

A cantilever beam of 2 m long is loaded with a uniformly distributed load of 3 kN/m run over a length of 1 m from the free end. It also carries a point load of 5 kN at a distance of 1.5 m from the free end. Draw the S.F and B.M.

What do you mean by simple bending? What are the assumptions made in the theory of simple bending?

Show from first principles that if a beam of rectangular section is subjected to a transverse shearing force, the maximum shear stress at a cross-section is 1.5 times the mean shear stress.

An I-section beam consists of two flanges 160 mm × 25 mm and a web of 320 mm × 12 mm. Find the magnitude of maximum shear stress when it is subjected to a shear force of 60 kN.

Explain with reasons which theory of failure is best suited for i) Ductile materials and ii) Brittle materials.

A point in a strained material is subjected to mutually perpendicular stresses of 40 N/mm² (tensile) and 20 N/mm² (compressive). It is also subjected to a shear stress of 20 N/mm². Draw Mohr’s circle and find the principal stresses and maximum shear stress.

Derive an expression for the stresses on an oblique plane of a rectangular body, when the body is subjected to a simple shear stress.

Derive an expression for the distortion energy per unit volume when a body is subjected to principal stresses σ₁, σ₂, σ₃.

A cylindrical shell is subjected to internal fluid pressure. Find an expression for change in diameter and change in length of the cylinder?

A hollow shaft has to transmit 337.5 kW at 100 rpm. If the shear stress is not to exceed 65 N/mm² and the internal diameter is 0.6 of the external diameter, find the external and internal diameters assuming that the maximum torque is 1.3 times mean.

Define the term polar modulus. Find the expression for polar modulus for a solid shaft and for a hollow shaft.

A spherical shell of 1.5 m diameter is subjected to an internal pressure of 1.45 N/mm². Taking the maximum allowable stress as 110 N/mm², find the necessary thickness of plate. Take the joint efficiency at 71%.