Rotational Stiffness Calculator

Calculate rotational stiffness from applied moment and angle of rotation

Calculate Rotational Stiffness

Torque or moment applied to cause rotation

Angle through which the object rotates

Rotational Stiffness Results

0.000
N⋅m/rad
0.000000
kN⋅m/rad
0.000
N⋅m/deg
0.000
lb⋅ft/rad

Formula used: k = M / θ

Input values: M = 0.000 N⋅m, θ = 0.000000 rad

Interpretation: Enter values to see interpretation

Stiffness Analysis

Example Calculation

Structural Beam Example

Applied Moment: 16 N⋅m

Rotation Angle: 0.7 radians

Material: Steel structural beam

Calculation

k = M / θ

k = 16 N⋅m / 0.7 rad

k = 22.857 N⋅m/rad

Common Unit Conversions

Moment Units:
1 kN⋅m = 1000 N⋅m
1 lb⋅ft = 1.356 N⋅m
1 kgf⋅m = 9.807 N⋅m
Angle Units:
1 degree = π/180 radians
1 revolution = 2π radians
1 radian = 57.296 degrees

Applications

🏗️

Foundation design for structures subjected to rocking motion

🏢

Structural element rigidity in building construction

✈️

Aircraft wing design and vibration analysis

🌊

Offshore wind turbine platform stability

🔧

Mechanical component design and analysis

Understanding Rotational Stiffness

What is Rotational Stiffness?

Rotational stiffness is a property of a body that defines its resistance to rotational deformation under applied moments or torques. It represents the amount of moment required to produce a unit angle of rotation.

Physical Significance

  • Higher stiffness means greater resistance to rotation
  • Related to material properties and geometry
  • Critical for structural stability analysis
  • Important in vibration and dynamic analysis

Formula and Units

k = M / θ

  • k: Rotational stiffness (N⋅m/rad)
  • M: Applied moment or torque (N⋅m)
  • θ: Angle of rotation (radians)

Units: The standard unit is N⋅m/rad (Newton-meters per radian). Other common units include kN⋅m/rad and N⋅m/degree.

Relationship to Linear Stiffness: Just as linear stiffness relates force to displacement (k = F/δ), rotational stiffness relates moment to angular displacement.