1. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
همد نظرية الإنشاءات (2) (3 ساعات معتمدة)
المتطلب السابق همد 201
خواص المساحات المستوية – الإجهادات المحورية – اجهادات القص )قوي القص – عزم الالتواء( – الإجهادات المركبة والأساسية .
CIV Theory of Structures (2) (3 Credit Hours)
Prerequisite CIV 201
Properties of plane areas – normal stresses – shear stresses (shearing force – torsional moment) – combined and principle stresses.

2. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
Properties of Areas
Centroid
Moments of inertia
Radius of gyration
Principal axes of inertia
Centroids of general bodies
Stresses
Normal Stresses (due to normal force and bending moment)
Shear Stresses (due to shear force and twisting moment)
Principal Stresses

3. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
Centroid
- Area:
It is always a positive quantity and its dimension is a length square (mm2, cm2, m2, ...).
- First moment of area about the y-axis:
It is the product of the area A and the distance .

4. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
Centroid
For simple symmetrical shapes (e.g.; rectangle, circle, …), the position of the centroid is obvious.
For shapes having an axis of symmetry, the centroid lies on this axis of symmetry
For shapes having more than axis of symmetry, the centroid lies on the intersection point of these axes of symmetry
For shapes symmetric about a point, like the Z-section, the center of symmetry is the centroid.

5. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
Centroid
Example:
Calculate the first moment of area for the shown shape about the x-axis (bottom edge). Also, find the position of the centroid.
Solution:
The centroid is mm from the bottom edge.

6. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
Centroid
Example:
Determine the position of the centroid of the shown area.
Solution:
The centroid is 8.51 cm from the left edge and 4.61 cm from the bottom edge.

7. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
Centroid
Example:
Determine the position of the centroid of the shown area.
Solution:
The centroid is m from the bottom edge.

8. CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
Centroid
Example:
Determine the position of the centroid of the shown steel cross-section. The properties of the channel and the angle are as given:
Solution:
The centroid is 8.62 cm from the left edge and cm from the bottom edge.

9. Thank You CIV 202 - THEORY OF STRUCTURES (2)
Giza Higher Institute for Eng. & Tech. - Dr. M Abdel-Kader
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