IS 2380 Part 23:1981 specifies a standardized vibration test method for wood particle boards and boards made from other lignocellulosic materials. This test evaluates the dynamic resonant frequency and stiffness of particle boards, providing a non-destructive means to assess their mechanical properties under vibration. It is essential for manufacturers, researchers, and quality control engineers involved in the production and testing of particle boards to ensure performance consistency and suitability for structural and furniture applications.
Overview
IS 2380 Part 23:1981 specifies a standardized vibration test method for wood particle boards and boards made from other lignocellulosic materials. This test evaluates the dynamic resonant frequency and stiffness of particle boards, providing a non-destructive means to assess their mechanical properties under vibration. It is essential for manufacturers, researchers, and quality control engineers involved in the production and testing of particle boards to ensure performance consistency and suitability for structural and furniture applications.
Audience
Contents
Structure
Scope:
This part of IS 2380 covers the determination of the dynamic modulus of elasticity (Young's modulus) of timber specimens by resonant frequency methods, harmonized internationally and adapted for Indian practices.
Specimen Size:
Rectangular specimen of 70 cm (length) x 30 cm (width).
Support Points:
Located at a distance of 0.224 × specimen length from each end to simulate zero displacement.
Dynamic Modulus of Elasticity (E):
Calculated from fundamental resonant frequency using:
[ E = \frac{1036 \times b \times d^3 \times f^2}{l^3 \times w} ]
Where:
Testing Procedure:
Rounding Off:
Follow IS 2-1960 for rounding test results.
flowchart LR
A[Specimen: 70x30 cm] --> B[Supported at 0.224*l from ends]
B --> C[Excited by variable frequency oscillator & loudspeaker]
C --> D[Measure fundamental frequency (f) with oscilloscope]
D --> E[Calculate E using formula]
Summary: This standard defines a precise method to measure the dynamic modulus of elasticity of timber using resonance frequency, ensuring consistent, internationally aligned testing.
IS 2380 Part 23 (1981) — Key Formula for Dynamic Modulus of Elasticity (Method B):
The Young’s modulus (dynamic modulus of elasticity in bending) E is calculated from the fundamental frequency of vibration of a timber specimen by:
[ E = 1036 \times \frac{l^3 \times f^2 \times w}{b \times d^3} ]
Where:
graph LR
A[Specimen] --> B(Length, l)
A --> C(Width, b)
A --> D(Thickness, d)
A --> E(Weight, w)
A --> F(Frequency, f)
This formula is central to IS 2380 Part 23 for determining timber's dynamic modulus of elasticity by vibration method.
IS 2380 Part 23: Test Specimen & Key Formulas
[ E = \frac{1036 \times L \times b \times d^3 \times f^2}{w} ]
Where:
| Parameter | Value/Range | Accuracy |
|---|---|---|
| Specimen Shape | Square | - |
| Side length (a) | 25h ≤ a ≤ 40h | ±0.1 mm |
| Thickness (h) | Measured | ±0.1 mm |
| Conditioning | 65 ± 5% RH, 27 ± 2℃ | - |
| Weight (w) | Measured | ±0.01 g |
| Test Specimen Size | 70 cm × 30 cm (rectangular) | - |
| Support distance | 0.224 × length from ends | - |
| Frequency (f) | Fundamental resonant frequency | - |
flowchart LR
A
IS 2380 Part 23: Test Procedure Key Points
[ 25h \leq a \leq 40h ]
[ d = 0.224 \times L ]
graph LR
A[Test Specimen] --> B[Square shape]
B --> C[Side a = 25 to 40 × thickness h]
A --> D[Conditioning: 65 ± 5% RH, 27 ± 2°C]
E[Test Setup] --> F[Rectangular specimen 70×30 cm]
F --> G[Supports at 0.224 × length from ends]
E --> H[Loudspeaker excitation below specimen]
E --> I[Pickup above specimen surface]
I --> J[Oscilloscope measures fundamental frequency]
This ensures accurate resonance frequency measurement for material characterization.
IS 2380 Part 23 — Key Formula for Dynamic Modulus of Elasticity (E):
The dynamic modulus of elasticity in bending is calculated from the fundamental resonant frequency of the specimen using:
[ \boxed{ E = \frac{1036 \times b \times d^3 \times f^2}{l^3 \times w} } ]
Where:
flowchart LR
A[Specimen Dimensions: b, d, l] --> B[Measure Fundamental Frequency f]
B --> C[Measure Weight w]
C --> D[Calculate E using formula]
D --> E[Dynamic Modulus of Elasticity E]
This method (Method 'B') provides a nondestructive way to estimate timber elasticity.
IS 2380 Part 23 - Key Formulas and Report Specifications
The report must include:
[ E = \frac{1036 \times b \times d^3 \times f^2}{w \times l^3} ]
Where:
| Symbol | Description | Unit |
|---|---|---|
| E | Dynamic modulus of elasticity in bending | kg/cm² |
| b | Width of specimen | cm |
| d | Thickness of specimen | cm |
| f | Fundamental resonant frequency (Hz) | cycles/sec |
| w | Weight of specimen | kg |
| l | Length of specimen | cm |
| Parameter | Unit/Details |
|---|---|
| Resonant Frequency (N) | Hz |
| Specimen Size | Length (l), Width (b), Thickness (d) in cm |
| Weight (w) | kg (at specified humidity/temp) |
| Dynamic Modulus (E) | kg/cm² |
| Moisture Content | Percentage (%) |
flowchart LR
A[Specimen Details] --> B[Measure Resonant Frequency (f)]
B --> C[Calculate E using formula]
C --> D[Calculate Stiffness (S)]
D --> E[Compile Report with all details]
This ensures compliance with IS 2380
Frequently Asked
According to IS 2380 Part 23, the test specimen requirements are:
| Parameter | Value/Range | Accuracy |
|---|---|---|
| Specimen shape | Square | - |
| Side length (a) | 25h ≤ a ≤ 40h | ± 0.1 mm |
| Thickness (h) | Measured | ± 0.1 mm |
| Humidity | 65% ± 5% | - |
| Temperature | 27°C ± 2°C | - |
| Weight accuracy | - | ± 0.01 g |
This ensures uniformity and reproducibility in testing wood particle boards and similar lignocellulosic materials.
Determination of Resonant Frequency of Particle Boards as per IS 2380 Part 23
Specimen Preparation:
Test Setup:
Procedure:
Resonant Frequency (N):
Stiffness Calculation:
| Step | Description |
|---|---|
| Iron piece attachment | At specimen center |
| Mounting | Rigid frame |
| Driver placement | Below iron piece |
| Frequency variation | Using calibrated oscillator |
| Vibration detection | Electromagnetic/piezoelectric pickup |
| Resonant frequency | Frequency at max amplitude |
| Stiffness ( S ) | Calculated from resonant frequency and thickness |
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This method is non-destructive and evaluates dynamic stiffness and resonant characteristics of particle boards.
As per IS 2380 Part 23 (1981), the equipment necessary for performing the vibration test on particle boards includes:
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This ensures accurate resonance frequency measurement for particle board characterization.
According to IS 2380 Part 23, the dynamic modulus of elasticity (E) from vibration test data is calculated using the fundamental resonant frequency of a rectangular specimen.
[ \boxed{ E = \frac{1036 \times b \times d^3 \times f^2}{l^3 \times w} } ]
Where:
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This approach provides a reliable estimate of stiffness under dynamic loading for particle boards.
To comply with IS 2380 Part 23, the test report must include the following details:
This ensures consistency and traceability in reporting particle board stiffness and resonant frequency tests.
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