1. What is Plastic Section Modulus?

The plastic section modulus (Z_p) is a geometric property of a cross-section that describes its capacity to resist plastic bending. It's used in plastic design to determine the moment capacity when the entire section yields.

2. How Does the Calculator Work?

The calculator uses the plastic modulus formula for rectangular sections:

Where:

• \( Z_p \) — Plastic section modulus (m³)
• \( A \) — Cross-sectional area (m²)
• \( d \) — Depth of section (m)

Explanation: The formula calculates the plastic moment capacity by considering the entire cross-section yielding in tension and compression.

3. Importance of Plastic Modulus

Details: Plastic section modulus is crucial in plastic design methods where redistribution of moments is considered, allowing for more economical designs compared to elastic methods.

4. Using the Calculator

Tips: Enter the cross-sectional area in m² and depth in m. Both values must be positive numbers. The calculator will compute the plastic section modulus in m³.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between plastic and elastic section modulus?
A: Elastic modulus (Z) considers stress within elastic limit, while plastic modulus (Z_p) considers full plastic capacity of the section.

Q2: Is this formula valid for all cross-sections?
A: This specific formula is for rectangular sections. Other shapes have different formulas for plastic modulus.

Q3: How does plastic modulus affect design?
A: Higher plastic modulus means greater moment capacity, allowing for smaller sections in plastic design.

Q4: When should plastic modulus be used?
A: In plastic design methods where moment redistribution is considered, and in calculating ultimate moment capacity.

Q5: What are typical values for plastic modulus?
A: Values vary widely based on section size and shape, ranging from 10^-6 m³ for small sections to 10^-2 m³ for large structural members.