The image above represents the stiffness performance index. To calculate the stiffness performance index, two essential parameters are needed and these parameters are Shear Modulus (G) and Density (ρ).
The formula for calculating stiffness performance index:
P = √(G)/ρ
Where:
P = Stiffness Performance Index
G = Shear Modulus
ρ = Density
Let’s solve an example;
Find the stiffness performance index when the shear modulus is 36 and the density is 12.
This implies that;
G = Shear Modulus = 36
ρ = Density = 12
P = √(G)/ρ
That is, P = √(36)/12
P = 6/12
P = 0.5
Therefore, the stiffness performance index is 0.5
Calculating the Shear Modulus when the Stiffness Performance Index and the Density are Given
G = (P x ρ)2
Where:
G = Shear Modulus
P = Stiffness Performance Index
G = Shear Modulus= Stiffness Performance Index
ρ = Density
Let’s solve an example;
Find the shear modulus when the stiffness performance index is 25 and the density is 5.
This implies that;
P = Stiffness Performance Index = 25
ρ = Density = 5
G = (P x ρ)2
So, G = (25 x 5)2
G = 15,625
Therefore, the shear modulus is 15,625.
Read more: How to Calculate and Solve for Performance Index | Material Selection
Calculating the Density when the Stiffness Performance Index and Shear Modulus are Given
ρ = √(G) / P
Where;
ρ = Density
P = Stiffness Performance Index
G = Shear Modulus
Let’s solve an example;
Find the density when the stiffness performance index is 4 and the shear modulus is 64.
This implies that;
P = Stiffness Performance Index = 4
G = Shear Modulus = 64
ρ = √(G) / P
ρ = √64 / 4
Then, ρ = 8 / 4
ρ = 2
Therefore, the density is 2.
How to Calculate Stiffness Performance Index With Nickzom Calculator
Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the stiffness performance index.
To get the answer and workings of the stiffness performance index 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 for NGN 2,000 per annum 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 Material Selection under Materials and Metallurgical
Now, Click on Stiffness Performance Index under Material Selection
The screenshot below displays the page or activity to enter your values, to get the answer for the stiffness performance index according to the respective parameter which is the Shear Modulus (G) and Density (ρ).
Now, enter the values appropriately and accordingly for the parameters as required by the Shear Modulus (G) is 36 and Density (ρ) is 12.
Finally, Click on Calculate
As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the stiffness performance index and presents the formula, workings and steps too.