What is the Grashof condition?

The Grashof condition S+L ≤ P+Q (where S is shortest and L is longest link) determines whether continuous rotation is possible. If satisfied, at least one link can make a full revolution.

What are the four-bar linkage types?

Depending on which link is grounded: crank-rocker (input rotates, output oscillates), double-crank (both rotate), rocker-crank (oscillating input, rotating output), double-rocker (both oscillate).

How is four-bar linkage motion analyzed?

Position analysis uses the loop-closure equation. Velocity and acceleration analyses use differentiation. Graphical methods (velocity diagrams) or analytical/computational methods can be used.

Four-Bar Linkage Grashof Condition Calculator

Check Grashof condition: S+L ≤ P+Q where S=shortest, L=longest link. Determine linkage type: crank-rocker (S=input), double-crank (S=ground), double-rocker, or change-point mechanism.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Check Grashof condition: S+L ≤ P+Q where S=shortest, L=longest link. Determine linkage type: crank-rocker (S=input), double-crank (S=ground), double-rocker, or change-point mechanism. Use the four-bar grashof result to inform your clinical assessment.

Related Calculators

Slider-Crank

Engineering

Flywheel Energy