Quick guide
How to use this calculator
- Choose the analysis mode that matches the physical model before entering values.
- Enter properties, geometry, loads, states and coefficients from one consistent unit and sign convention.
- Use the intermediate outputs to audit the relationship, then retain the stated idealization before applying it.
Calculation method
Transparent engineering model
With simple end supports and constant EI, MB=−(w₁L₁³+w₂L₂³)/(8(L₁+L₂)); each span reaction follows end-moment equilibrium.
The calculator evaluates only the declared relationship and preserves visitor-entered assumptions rather than selecting materials, factors, components or standards.
Worked example
Worked example
Two 5 m spans carrying 10 kN/m each produce a −31.25 kN·m interior support moment and 18.75/62.5/18.75 kN reactions.
With simple end supports and constant EI, MB=−(w₁L₁³+w₂L₂³)/(8(L₁+L₂)); each span reaction follows end-moment equilibrium.
Supported inputs
Precision and limits
Analysis, not approval
This release intentionally covers two prismatic spans with unyielding simple end supports and full-span UDLs. General multi-span stiffness analysis belongs in the frame solver.
Standards and properties
Material properties, allowable values, load combinations, safety factors, correlations, manufacturer data, codes and jurisdictional requirements are not supplied automatically.
Units and precision
Use one consistent unit basis. Results retain working precision but cannot be more accurate than the entered measurements and properties.
Privacy
Entered engineering values and results stay in this browser and are not sent to analytics or third parties.