# Finite Element Method Questions and Answers – Dynamic Considerations Formulation

This set of Finite Element Method Multiple Choice Questions & Answers (MCQs) focuses on “Dynamic Considerations Formulation”.

1. What is the periodic motion due to restraining strain energy referred to as?
a) Free vibration
b) Damped vibration
c) Un damped vibration
d) Simple harmonic motion

Explanation: The periodic motion due to restraining strain energy is referred to as free vibration. This type of motion arises as a result of elastic deformation for short duration of time which causes the body to vibrate along it’s equilibrium position.

2. What is Hamilton’s principle also referred to as?
a) Principle of highest action
b) Principle of least action
c) Principle of last action
d) Principle of most action

Explanation: Hamilton’s principle is also referred to as principle of least action. This principle is used to determine the co-ordinates and motion of the particle under consideration. This is an example of Classical Physics formulation.

3. Which of the following is not true regarding modal superposition?
a) It helps reduce Computation time
b) It makes job of user easy
c) It increases computation time
d) It superimposes eigenmodes

Explanation: Modal superposition is used explicitly in dynamic analysis. It is a powerful technique used for reducing computation time. Dynamic response to load can be approximated by superimposing the eigenmodes of the structure under discussion.

4. The natural frequencies of vibration of a system are reduced by the effect of damping.
a) True
b) False

Explanation: In damped vibration, there is an external force applied. This external force has the power to amplify or diminish the frequencies of the system. By general convention, a damping force reduces the natural frequency of a given system.

5. Which of the following is the matrix expression of Rayleigh’s damping?
a) C = μM – λK
b) C = μM * λK
c) C = μM / λK
d) C = μM + λK

Explanation: Rayleigh’s Damping can be expressed in matrix form as – C = μM + λK. Here, M and K correspond to mass and stiffness matrices respectively, and μ, λ are constants of proportionality. Classical Rayleigh’s damping is also referred to as viscous damping.

Sanfoundry Global Education & Learning Series – Finite Element Method.

To practice all areas of Finite Element Method, here is complete set of 1000+ Multiple Choice Questions and Answers.