FEA interview questions in Engineering mechanics

1. What is force?

• A force can affect both the motion and the deformation of the body on which it acts. Forces may arise from direct contact between bodies, or they may be applied at a distance (such as gravitational attraction).
• Contact forces are distributed over a surface area of the body, whereas forces acting at a distance are distributed over the volume of the body.

2. Classification of force?

3. What are Characteristics of a force?

There are two Characteristics of force.

Magnitude

Direction

This makes force as a vector quantity. Having both magnitude and direction.

4. What is meant by Resultant Force?

N number of the forces acting in a system, can be replaced by a single force, Which could produce the same effect as produced by the all the forces, that single force is called resultant force.

5. State Lami's theorem?

• If three coplanar, concurrent and non-collinear forces acting on a particle keep it in equilibrium, each is proportional to the sine of the angle between the other two.
• According to the theorem, where A, B and C are the magnitudes of three coplanar, concurrent and non-collinear forces, which keep the object in static equilibrium, and α, β , γ are the angles directly opposite to the forces A, B and C respectively.
A/sinα =B/ sin β = c/ sin γ

6. Triangle law of forces?

Triangle law of forces states that, If two forces acting at a point are represented in magnitude and direction by the two adjacent sides of a triangle taken in order, then the closing side of the triangle represents the resultant of the force.

7. Polygon law of forces?

If a number of forces acting at a point be represented in magnitude and direction by the sides of a polygon in order, then the resultant of all these forces may be represented in magnitude and direction by the closing side of the polygon taken in opposite order.

8. What is the procedure to draw the free-body diagram?

• Isolation of a part from the system
• Show all the forces acting on the part
1. Active forces – tends to set the particle in motion.
2. Reactive forces – Results of constraints or supports that tend to prevent motion.
• Identify each forces
1. The forces that are unknown must labeled with their proper magnitude and directions.