MM (B-TECH Automobile Engineering 3rd)

Simple, Compound Stresses and Strains: Stress and Strain and their types, Hook’s law,

longitudinal and lateral strain, Poisson’s ratio, stress-strain diagram for ductile and brittle

materials, Stress in a bar, Analysis of bars of varying sections, composite section, elastic

constants and their significance, Temperature stress and strain calculation due to axial load and

variation of temperature in single and compound bars. Two dimensional stress system, stress at

a point on a plane, principal stresses and principal planes, Mohr’s circle of stress.

Bending Moment (B.M) and Shear Force (S.F) Diagrams: S.F and B.M definitions; relation

between load, shear force and bending moment; B.M and S.F diagrams for cantilevers, simply

supported beams with or without overhangs, and calculation of maximum B.M and S.F and the

point of contra flexure under the following loads:

a) Concentrated loads

b) Uniformity distributed loads over the whole span or part of span

c) Combination of concentrated and uniformly distributed load

Bending Stresses In Beams: Pure Bending or simple bending, Neutral axis and moment of

resistance, Assumptions in the simple bending theory; derivation of formula and its application

to beams of rectangular and circular section. Section modulus, section modulus for circular and

rectangular section beam, combined direct and bending stresses, bending stress of composite /

flitched beams.

Shear stresses in beams: Shear stress at a section, Shear stress distribution in rectangular and

circular sections.

Torsion: Derivation of torsion equation, assumptions and its application to the hollow and solid

circular shafts, Torsional rigidity, Power transmitted by the shaft, Modulus of rupture,

comparison of solid and hollow shafts, principal stress and maximum shear stresses under

combined loading of bending and torsion of circular shaft.

Columns and struts: Introduction, failure of columns, Euler’s formula and assumptions,

different end conditions, Limitations of Euler’s formula. Rankine-Gordon’s formula.

Theories of failure: Strain energy in tension, compression, shear, bending and torsion

Maximum principal stress theory, maximum shear stress theory, maximum principal strain

theory, total strain energy theory, shear strain energy theory. Graphical representation and

derivation of equation for these theories and their application to problems related to two

dimensional stress systems.

Thin cylinders: Calculation of Hoop stress, longitudinal stress in a thin cylinder, effect of internal

pressure on the change in diameter, length and internal volume.