Math Problem Statement
calculation of inertia at x and y axis
Solution
The diagram you've provided depicts an I-beam with given dimensions, and you'd like to calculate the moment of inertia (second moment of area) about the x-axis (horizontal axis) and the y-axis (vertical axis). Here's how we can approach it.
Given dimensions:
- Overall width of the beam flange = 200 mm
- Thickness of the flange = 15 mm
- Height of the I-beam = 300 mm
- Thickness of the web = 15 mm
We will calculate the moment of inertia using the following formulas for composite sections.
1. Moment of Inertia About the X-axis ():
For the x-axis, we decompose the I-beam into three parts:
- Two rectangular flanges (top and bottom)
- One rectangular web (the vertical central section)
The parallel axis theorem will be applied to move the moment of inertia of the flanges to the centroid of the I-beam.
The formula for the moment of inertia of a rectangle about its centroid is:
Where:
- is the width of the rectangle.
- is the height of the rectangle.
2. Moment of Inertia About the Y-axis ():
For the y-axis, the I-beam is symmetric, so we just sum the moments of inertia of each section without needing to apply the parallel axis theorem.
I will now proceed with these calculations.The moments of inertia for the given I-beam are:
- Moment of Inertia about the x-axis ():
- Moment of Inertia about the y-axis ():
These values reflect the beam's resistance to bending around the respective axes.
Would you like more details or have any questions on this?
Here are five related questions you might consider:
- How does increasing the thickness of the web affect the moment of inertia about the x-axis?
- How do we apply the parallel axis theorem in these calculations?
- Why is the moment of inertia about the x-axis larger than that about the y-axis?
- What is the significance of the moment of inertia in structural analysis?
- How would the moment of inertia change if the material was different but dimensions were the same?
Tip: The higher the moment of inertia, the more resistance the beam has to bending in that particular direction.
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Structural Engineering
Moment of Inertia
Mechanics of Materials
Formulas
Moment of inertia of a rectangle: I = (bh^3)/12
Parallel Axis Theorem: I_total = I_centroid + Ad^2
Theorems
Parallel Axis Theorem
Suitable Grade Level
Undergraduate Civil/Mechanical Engineering
Related Recommendation
Calculate Moment of Inertia for I-Beam Cross-Section
How to Calculate the Moment of Inertia (Ix) of a Symmetrical I-Beam Cross-Section
Moment of Inertia and Beam Analysis for an I-Beam with Applied Loads
Computation of Moment of Inertia and Beam Analysis with Point and Distributed Loads
Moment of Inertia Calculation for I-Beam - X-axis and Y-axis