Course on Theory of Plasticity

About Course

Theory of plasticity deals with the study of deformable bodies for displacement, strain and stresses when the bodies are subjected to external stimuli inducing plastic stresses i.e. beyond elastic limit.


Plasticity describes the deformation of a material undergoing non-reversible changes of shape in response to applied forces.The key fundamental mechanism of metal plasticity is movement of atoms along atomic slip planes.Plasticity in a crystal of pure metal is primarily caused by two modes of deformation in the crystal lattice: slip and twinning. Slip is a shear deformation which moves the atoms through many interatomic distances relative to their initial positions.The theory of plasticity is the branch of mechanics that deals with the calculation of stresses and strains in a deformable body in which a material will not fail when subjected to the action of a force,but will not recover completely so that a permanent deformation results when the applied forces are removed.Thus theory of plasticity describe the plastic behaviour of materials.

What Will I Learn?

  • Visualise the concepts of Plasticity and mechanism of plastic deformation in metals.
  • Understand deformations, , strain, stress, relation between stress and strain in plastic range and associated flow rules.
  • Interpret the importance of plastic deformation of metals in engineering problems.
  • Analyse the yielding of a material according to different yield theory for a given state of stress.

Topics for this course

7 Lessons40h

Brief review of fundamentals of elasticity

Brief review of fundamentals of elasticity: Concept of stress, stress invariants, principal Stresses,octahedral normal and shear stresses, spherical and deviatoric stress, stress transformation; concept of strain, engineering and natural strains, octahedral strain, deviator and spherical strain tensors, strain rate and strain rate tensor, cubical dilation, generalized Hooke’s law, numerical problems.

Plastic Deformation of Metals

Yield Criteria

Stress Strain Relations

Bending of Beams

Torsion of Bars

Slip Line Field Theory

About the instructor

Dr. Jagadish T

Director, Research and Development

0 (0 ratings)

54 Courses

5 students



  • The prerequisites required are fundamental knowledge in material science, thermodynamics, heat transfer, numerical techniques, computer programming, industrial engineering.

Target Audience

  • Engineers working in construction and maintenance of buildings, mechanical, automotive, aerospace, railways, defence, nuclear energy, thermal power, wind, medical equipment, etc, and related Industry can participate.
Virtual Engineering
# 28 (Old No 619/1), 2nd Floor
36th Cross, 2nd Block, Rajajinagar
Bangalore-560010 India