MDB

• Stress


  A physical quantity that expresses the internal forces that the neighboring particles of a continuous material exert on each other
• Types of internal forces/stresses

  • Normal/Axial stress
  • Shear stress
  • Bending stress
• Normal/Axial stress


  Load is "normal" or "perpendicular" to the section
• Shear stress


  Load is acting "parallel" to the section
• Bending stress


  Section is bent with compression and tension
• Strain


  The ratio of change of length caused by an applied force, to original length
• Hooke's Law


  For relatively small deformations of an object, the displacement or size of the deformation is directly proportional to deforming force load. In this condition, it returns to original shape and size upon the removal of load due to elasticity
• Young's Modulus of Elasticity


  A quantity that measures an object or substance resistance to being deformed elastically when a stress is applied to it. It is a measure of Stiffness
• Stress and Strain Diagram


  Shows the relation between the stress and strain
• Proportional Limit (P)


  The point from 0 (origin) where Hooke's Law holds true. The Stress-Strain Diagram is linear
• Elastic Limit (E)


  The point where the material cannot go back to its original shape when load is removed
• Yield Point (Y)


  The point where the material has elongation or yielding without increasing the load
• Ultimate Strength


  The maximum strength of material against the load
• Rupture Strength


  The strength of rupture. Breaking Strength
• Modulus of Resilience


  The maximum amount of energy per volume that can absorb while elastically deforming
• Modulus of Toughness


  The maximum amount of energy per volume that can absorb before it fractures
• Factor of Safety


  A concept used in engineering to indicate how much stronger a structure or system designed to be compared to actual loads
• Poisson's Ratio


  A ratio of proportional decrease in lateral measurement to the proportional increase in length in sample
• Torsion


  An action of twisting or the state of being twisted, especially of one end of an object relative to other
• Torsional Stress


  A form of shear stress experience by a body when twisting force is applied
• Thermal Stresses


  The stress produced by any change in the temperature of material
• Indeterminate Connections and Deformations


  A topic related to structural engineering, specifically dealing with the analysis of structures with indeterminate connections and deformations. This involves studying the behavior of structures under various loading conditions and determining the internal forces, stresses, and deformations that occur
• Vertical Shear Forces (Beam Shear)


  Forces generated in the beam by applied loads and by support reaction. The reactions push up the beam while the load push it down
• Bending Moment


  The moment which causes the bending effect
• Moment of Inertia of Composite Areas


  The resistance of a section to change in rotation due to its shape (angular acceleration) in some instance caused by bending
• Centroidal Moment of Inertia


  The resistance of a shape to rotate about its centroid
• Parallel Axis Theorem


  Also known as Huygens-Steiner Theorem, it is used for finding the moment of inertia of the area of a rigid body whose axis is parallel to the axis of the known moment body, and it is through the center of gravity of the object
• First Moment of Area


  A measure of the distribution of the area of a shape in relation to an axis (for structural analysis, Q is with respect to the neutral axis). It is acquired by taking the moment of the area about the target axis
• Section Modulus


  A geometric property for a given cross-section used in the design of beams or flexural members
• Types of Stiffness Based on Type of Deformation

  • Axial Stiffness
  • Rotational Stiffness
  • Lateral Stiffness
  • Torsional Stiffness
  • Bending Stiffness
  • Shear Stiffness
• Axial Stiffness


  Resistance towards axial deformation due to the applied tension (or compression)
• Rotational Stiffness


  The ability of a material to resist rotation caused by applied Moment
• Lateral Stiffness


  The ability of a body to resist lateral deflection when a lateral force is applied. It is also called as Storey Stiffness
• Torsional Stiffness


  The ratio of applied Torsional moment to the angle of twist
• Bending Stiffness


  The resistance of a member against bending. For beams, flexural rigidity is considered as bending stiffness
• Shear Stiffness


  The ratio of Shear force to Shear deformation
• Material Compatibility

   it ensures that deformations within a material are achievable and don't lead to inconsistencies 
• Structural Compatibility


  Deals with how different parts of a structure move together when subject to loads
• Deflection


  Change in position, Units of length (mm,in), can be reversible (elastic), Ex. Bending a Ruler
• Deformation


  Change in shape or size, involve change in length, area and volume, can be reversible (elastic) or irreversible (plastic), Ex. Stretching a rubber band