Formula for Impact Energy:
E=m⋅g⋅hE = m \cdot g \cdot h
Where:
- E = Impact Energy (Joules) = 15 J
- m = Mass of the steel ball (kg)
- g = Gravitational acceleration = 9.81 m/s²
- h = Drop height (m)
Weight Calculation:
Rearranging the formula to find m: m=Eg⋅hm = \frac{E}{g \cdot h}
- If the drop height (h) is 1 meter:
m=159.81⋅1=159.81≈1.53 kgm = \frac{15}{9.81 \cdot 1} = \frac{15}{9.81} \approx 1.53 \, \text{kg}
- If the drop height (h) is 0.5 meters:
m=159.81⋅0.5=154.905≈3.06 kgm = \frac{15}{9.81 \cdot 0.5} = \frac{15}{4.905} \approx 3.06 \, \text{kg}
- If the drop height (h) is 0.2 meters:
m=159.81⋅0.2=151.962≈7.65 kgm = \frac{15}{9.81 \cdot 0.2} = \frac{15}{1.962} \approx 7.65 \, \text{kg}
Typical Steel Ball Weights and Heights:
- 1.5 kg ball dropped from 1 m.
- 3.06 kg ball dropped from 0.5 m.
- 7.65 kg ball dropped from 0.2 m.
A 15 Joule Impact Test refers to a material toughness test that measures the energy absorbed by a material when subjected to a sudden impact load of 15 Joules.
Purpose of the Test:
- To evaluate the material’s ability to withstand impact forces or sudden shocks without fracturing.
- Measures toughness, brittleness, and ductility of the material.
How is it Conducted?
- Test Setup:
- A pendulum hammer is used to strike the test specimen (usually a small bar or plate).
- Impact Load:
- The hammer releases 15 Joules of energy during the swing.
- Observation:
- The energy absorbed by the specimen during the impact is measured, indicating how much energy the material can dissipate before failure.
- Fracture Analysis:
- The type and appearance of the fracture are analyzed to assess brittle or ductile behavior.
Common Standards Used:
- Charpy Impact Test (ISO 179 or ASTM D256) – Tests toughness in notched or unnotched specimens.
- Izod Impact Test – Measures impact strength in vertical orientation.
Applications:
- Construction Materials: Evaluates the toughness of concrete, mortar, and fiber-reinforced composites.
- Plastic and Polymers: Determines suitability for pipes, coatings, and impact-resistant materials.
- Metals and Alloys: Tests structural steel, reinforcement bars, and welding joints.
Result Interpretation:
- High Energy Absorption = Ductile Material (e.g., steel).
- Low Energy Absorption = Brittle Material (e.g., ceramics).
Let me know if you’d like more details on testing procedures or results analysis!