Stress
Stress is force applied on crosssectional area.
Stress is the ratio between applied force and crosssectional area where the applied force is acting.
Normal Stress
Normal stress can be expressed as
σ = F_{N} / A (1)
where
σ = normal stress (N/m^{2}, Pa, psi)
F_{N} = applied force perpendicular to the area  Normal force (N, lb)
A = crosssectional area (m^{2}, in^{2})
Shear Stress
Shear stress can be expressed as
τ = F_{V} / A (2)
where
τ = shear stress (N/m^{2}, Pa, psi)
F_{V} = applied force in plane of the area  Shear force (N, lb)
Example  Normal Stress in a Column
A 10000 N force is acting in the direction of a British Universal Column UB 152 x 89 x 16 with cross sectional area 20.3 cm^{2}. The normal stress in the column can be calculated as
σ = (10000 N) / ((20.3 cm^{2}) (0.0001 m^{2}/cm^{2})
= 4926108 Pa (N/m^{2})
= 4.9 MPa
The Yield strength  the amount of stress that a material can undergo before moving from elastic deformation into plastic deformation  is typical 250 MPa for steel.
Example  Shear Stress in a Beam with Point Load
For a beam with single point load supported on both ends  the shear force F_{v} (or V in the figure above) is equal in magnitude to support force R_{1} or R_{2}.
Reaction forces can be calculated due to moment equilibrium around support 1
F L / 2 = R_{2} L (4)
R_{2} = F / 2 (5)
R_{1} = R_{2} = F / 2 (6)
For a 10000 N point load perpendicular on a beam similar to the example above  supported at both ends  the magnitude of the reaction and shear forces can be calculated as
R_{1} = R_{2}
= V_{1}
= V_{2}
= (10000 N) / 2
= 5000 N
= 5 kN
The shear stress can be calculated as
τ = (5000 N) / ((20.3 cm^{2}) (0.0001 m^{2}/cm^{2})
= 2463054 Pa
= 2.5 MPa
Related Topics

Mechanics
Forces, acceleration, displacement, vectors, motion, momentum, energy of objects and more. 
Statics
Loads  forces and torque, beams and columns.
Related Documents

Beams  Fixed at Both Ends  Continuous and Point Loads
Stress, deflections and supporting loads. 
Beams  Fixed at One End and Supported at the Other  Continuous and Point Loads
Supporting loads, moments and deflections. 
Beams  Supported at Both Ends  Continuous and Point Loads
Supporting loads, stress and deflections. 
Process Pipes  Allowable Stress vs. Temperature
Allowable wall stress in pipes according ASME M31.3. 
Restricted Thermal Expansion  Force and Stress
Stress and force when thermal expansion a pipe, beam or similar is restricted. 
Rotating Bodies  Stress
Stress in rotating disc and ring bodies. 
Shafts Torsion
The torsion of solid or hollow shafts  Polar Moment of Inertia of Area. 
Steam Boiler Shells  Stress vs. Boiler Pressure
Calculate the stress in steam boiler shells caused by steam pressure. 
Steels  Endurance Limits and Fatigue Stress
Endurance limits and fatigue stress for steels. 
Stress in ThickWalled Cylinders or Tubes
Radial and tangential stress in thickwalled cylinders or tubes with closed ends  with internal and external pressure. 
Stress in ThinWalled Cylinders or Tubes
Hoop and longitudinal stress thinwalled tubes or cylinders. 
Stress, Strain and Young's Modulus
Stress is force per unit area  strain is the deformation of a solid due to stress. 
Threaded Bolts  Stress Area
Threaded bolts tensile stress area. 
Young's Modulus, Tensile Strength and Yield Strength Values for some Materials
Young's Modulus (or Tensile Modulus alt. Modulus of Elasticity) and Ultimate Tensile Strength and Yield Strength for materials like steel, glass, wood and many more.