Paris' law

High school (ages 12+)
Science & Technology

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Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/paris-law

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the scientific name?Paris' Law (or Paris-Erdogan Equation)
2. What is the formula?da/dN = C(ΔK)m
3. What is Paris' Law and why is it important?Paris' Law is a rule that helps scientists predict how cracks grow in materials when they are repeatedly stressed. It lets engineers know how many times a part can be used before it might break.
4. How does Paris' Law describe the speed of a crack growing?It uses a formula that says the crack grows faster when the stress difference (ΔK) is bigger. The formula has two numbers, C and m, that are found by experiments.

Fatigue Crack Growth Rate (da/dN): The incremental increase in crack length per applied load cycle.
Stress Intensity Factor Range (ΔK): The difference between the maximum and minimum stress intensity factors during a loading cycle.
Empirical Constants (C, m): Material-dependent parameters determined experimentally to fit the Paris' Law equation.
Fracture Toughness: A measure of a material's resistance to fracture when a crack is present.