1. What is Vertical Bending Moment at Crank-web Joint?

The Vertical Bending Moment at Crank-web Joint is the bending force acting in the vertical plane at the juncture of crank-web and crankshaft, due to radial force applied on crank-pin. This mechanical stress parameter is crucial in crankshaft design and analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( M_v \) — Vertical Bending Moment at Crank-web Joint (N·m)
• \( P_r \) — Radial Force at Crank Pin (N)
• \( l_c \) — Length of Crankpin (m)
• \( t \) — Thickness of Crank Web (m)

Explanation: The formula calculates the bending moment caused by radial force acting at a distance equal to 0.75 times the crankpin length plus the crank web thickness from the juncture point.

3. Importance of Vertical Bending Moment Calculation

Details: Accurate calculation of vertical bending moment is essential for crankshaft design, stress analysis, fatigue life prediction, and ensuring structural integrity under maximum torque conditions.

4. Using the Calculator

Tips: Enter radial force in Newtons, length of crankpin in meters, and thickness of crank web in meters. All values must be positive numbers with appropriate units.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the 0.75 factor in the formula?
A: The 0.75 factor accounts for the effective lever arm distance where the radial force acts relative to the crank-web juncture, based on empirical data and mechanical design principles.

Q2: When is this calculation most critical?
A: This calculation is most critical during maximum torque conditions when the crankshaft experiences the highest bending stresses, particularly in internal combustion engines and heavy machinery.

Q3: How does crank web thickness affect the bending moment?
A: Thicker crank webs increase the distance from the force application point, resulting in higher bending moments. Proper web thickness is crucial for balancing strength and weight requirements.

Q4: What safety factors should be considered?
A: Typical safety factors range from 2-4 depending on application, material properties, operating conditions, and required reliability levels.

Q5: Can this formula be used for all crankshaft types?
A: This formula is specifically designed for side-crankshaft configurations. Different crankshaft geometries may require modified calculations or finite element analysis for accurate results.