Strain at Selected Level given Average Strain under Tension Calculator

Strain at Selected Level Formula:

\[ \varepsilon_1 = \varepsilon_m + \frac{W_{cr} \times (h_{Crack} - x) \times (D_{CC} - x)}{3 \times E_s \times A_s \times (L_{eff} - x)} \]

Average Strain (εₘ):

Crack Width (Wₖᵣ):

Height of Crack (h):

Depth of Neutral Axis (x):

Distance from Compression (DCC):

Modulus of Elasticity (Eₛ):

Area of Reinforcement (Aₛ):

m²

Effective Length (Lₑff):

Strain at Selected Level (ε₁):

1. What is Strain at Selected Level?

Definition: This calculator determines the strain at a selected level in a reinforced concrete element considering average strain and crack parameters.

Purpose: It helps structural engineers analyze the strain distribution in cracked concrete sections under tension.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \varepsilon_1 = \varepsilon_m + \frac{W_{cr} \times (h_{Crack} - x) \times (D_{CC} - x)}{3 \times E_s \times A_s \times (L_{eff} - x)} \]

Where:

\( \varepsilon_1 \) — Strain at selected level
\( \varepsilon_m \) — Average strain
\( W_{cr} \) — Crack width (m)
\( h_{Crack} \) — Height of crack (m)
\( x \) — Depth of neutral axis (m)
\( D_{CC} \) — Distance from compression to crack width (m)
\( E_s \) — Modulus of elasticity of steel reinforcement (Pa)
\( A_s \) — Area of reinforcement (m²)
\( L_{eff} \) — Effective length (m)

3. Importance of Strain Calculation

Details: Accurate strain calculation helps in assessing serviceability conditions, crack control, and deformation analysis in reinforced concrete structures.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Default values are provided for reference. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for average strain?
A: Average strain typically ranges from 0.0001 to 0.001 for service conditions.

Q2: How is crack width measured?
A: Crack width is usually measured in millimeters (converted to meters for calculation).

Q3: What affects the depth of neutral axis?
A: It depends on material properties, cross-section geometry, and loading conditions.

Q4: Why is modulus of elasticity important?
A: It determines the stiffness of steel reinforcement and affects strain distribution.

Q5: How precise should input values be?
A: For accurate results, input values should be as precise as possible (±5% tolerance).