MECH 4: MODULE 1

• Definition of Mechanics of Deformable Bodies:

  • Branch of physics and engineering mechanics
  • Studies behavior of materials undergoing deformation
  • Analyzes how forces and moments affect shape and motion of solid objects
  • Considers stress, strain, and material properties
  • Crucial in designing structures, predicting material response, and understanding mechanical behavior under various conditions
• Relationship between external applied loads and internal effects on the body is dealt with in mechanics of deformable bodies

  • Also known as strength of materials
• Purpose of studying mechanics of deformable bodies:

  • To know properties and dimensions of materials that satisfy requirements of strength and rigidity
  • Ensures structures used are safe against maximum internal effects produced by any combination of loading
• Internal forces under various loading conditions:

  • Force in stress analysis can be classified as internal or external
  • Resisting forces created within loaded structural elements are internal forces
  • Applied surface loads, force of gravity, and support reactions are external forces
  • Moment measures tendency of a force to cause a body to rotate around a particular point or axis
• Types of internal forces on a cross-section of a material subject to external loads:

  1. Normal force (or axial force), F:

  • Perpendicular to the cross-section
  • Measures pulling or pushing action over the section
  • Can be tensile force or compressive force

  2. Shear force, V:

  • Parallel to the cross-section
  • Component of total resistance to sliding the portion

  3. Bending moment, M:

  • Measures resistance to bending the member

  4. Twisting moment (or torque), T:

  • Measures resistance to twisting the member