1. What is Change in Eccentricity of Tendon B?

Definition: This calculator determines the change in eccentricity of tendon B between midspan and end points in a parabolic tendon profile.

Purpose: It helps structural engineers analyze prestressed concrete members by quantifying the eccentricity variation along the tendon length.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta e_B \) — Change in eccentricity B (meters)
• \( e_{B2} \) — Eccentricity at midspan B (meters)
• \( e_{B1} \) — Eccentricity at end for B (meters)

Explanation: The difference between midspan and end eccentricities gives the change in tendon position relative to the section's center of gravity.

3. Importance of Eccentricity Calculation

Details: Proper eccentricity analysis ensures correct moment generation in prestressed members and prevents undesirable stress distributions.

4. Using the Calculator

Tips: Enter eccentricity values in meters (with ±5% tolerance). Midspan eccentricity is typically greater than end eccentricity in parabolic profiles.

5. Frequently Asked Questions (FAQ)

Q1: Why is eccentricity important in prestressed concrete?
A: Eccentricity creates the moment needed to counteract service loads, improving structural performance.

Q2: What does a negative result indicate?
A: A negative ΔeB suggests the midspan eccentricity is less than the end eccentricity, which is unusual for standard parabolic profiles.

Q3: How precise should measurements be?
A: Measurements should be accurate to within ±5% for reliable results in structural applications.

Q4: Does this apply to all tendon profiles?
A: This specific formula applies to parabolic profiles. Other profiles (linear, draped) require different calculations.

Q5: How does this affect moment calculations?
A: The change in eccentricity directly affects the secondary moments generated in indeterminate structures.

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