# How to Calculate and Solve for Fracture Toughness Design Stress | Fracture

**Last Updated on June 4, 2024**

The image of fracture toughness design stress is represented below. Four essential parameters are needed to calculate fracture toughness design stress: the **Factor of Safety (N)**, the **Applied Load Constant (Y)**, the **Critical Wall Stress (σy)**, and the **Maximum Allowable Flow Length (a _{c}).**

**The formula for calculating fracture toughness design stress:**

K_{IC} = Y(^{σy}/_{N})√(πa_{c})

K_{IC} = Fracture Toughness Design Stress

Y = Applied Load Constant

N = Factor of Safety

σ_{y} = Critical Wall Stress

a_{c} = Maximum Allowable Flow Length

Given an example;

Find the fracture toughness design stress when the applied load constant is 7, the factor of safety is 4, the critical wall stress is 2 and the maximum allowable flow length is 8.

This implies that;

Y = Applied Load Constant = 7

N = Factor of Safety = 4

σ_{y} = Critical Wall Stress = 2

a_{c} = Maximum Allowable Flow Length = 8

K_{IC} = Y(^{σy}/_{N})√(πa_{c})

K_{IC} = 4(^{2}/_{7})√(π(8))

That is, K_{IC} = 4(0.285)√(25.132)

K_{IC} = 4(0.28)(5.013)

K_{IC} = 5.729

Therefore, the **fracture toughness design stress **is **5.729 J/cm².**

Read more: How to Calculate and Solve for Fracture Toughness | Fracture

**How to Calculate Fracture Toughness Design Stress With Nickzom Calculator**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the fracture toughness design stress.

To get the answer and workings of the fracture toughness design stress using the **Nickzom Calculator – The Calculator Encyclopedia. **First, you need to obtain the app.

You can get this app via any of these means:

**Web** – https://www.nickzom.org/calculator-plus

To get access to the **professional **version via web, you need to **register** and **subscribe **to have utter access to all functionalities.

You can also try the **demo **version via https://www.nickzom.org/calculator

**Android (Paid)** – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator

**Android (Free)** – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

**Apple (Paid)** – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8

Once, you have obtained the calculator encyclopedia app, proceed to the **Calculator Map, **then click on **Materials and Metallurgical **under **Engineering****.**

Now, Click on **Fracture**** **under **Materials and Metallurgical**

Now, Click on **Fracture Toughness Design Stress**** **under **Fracture**

The screenshot below displays the page or activity to enter your values, to get the answer for the fracture toughness design stress according to the respective parameter which is the **Factor of Safety (N), Applied Load Constant (Y), Critical Wall Stress (σ _{y}) **and

**Maximum Allowable Flow Length (a**

_{c}).Now, enter the values appropriately and accordingly for the parameters as required by the **Factor of Safety (N)** is **7**,** Applied Load Constant (Y)** is **4**,** Critical Wall Stress (σ _{y})** is

**2**and

**Maximum Allowable Flow Length (a**is

_{c})**8**.

Finally, Click on Calculate

As you can see from the screenshot above, **Nickzom Calculator**– The Calculator Encyclopedia solves for the fracture toughness design stress and presents the formula, workings and steps too.