# Foundations in Linear Dynamics using Ansys Mechanical - Theory Quiz

Note: The Expected Completion Time for this quiz is 60 mins, but the Maximum Available Time to complete it is 90 mins.

##### Total Number of Questions - 45

Times up! ##### Foundations in Linear Dynamics using Ansys Mechanical - Theory Quiz

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1 / 45

Which of these applications requires performing a dynamic analysis?

2 / 45

In a particular jet engine, the turbine blades are not perfectly balanced on the spin axis of the shaft. Choose the statement which describes the cause and effect of this imbalance with a turbine assembly that is in-service. Select the best option.

3 / 45

The displacement vector for a mode superposition solution with three modes is to be computed. The modal coordinate for each mode 1, 2 and 3 is 1 and for each of these modes, let's assume the value from the mode shape vector for a single node of interest is also 1. What will be the value of the nodal displacement calculated for this node of interest using these three modes?

4 / 45

Let us assume that there are two materials - "Material A" and "Material B". The stiffness and the density for Material A are both three times that of Material B. The ratio of natural frequencies for a structure made of Material A compared the same structure constructed with Material B will be _____. Complete the sentence with the best option.

5 / 45

Which of these materials is best suited for a flywheel to store most kinetic energy?

6 / 45

What is the relationship between displacement, velocity, and acceleration for a dynamic problem? Select the three best options.

7 / 45

Which of these is a time-dependent material behavior?

8 / 45

Structural dynamics is the study of _____. Select the best option to complete the sentence.

9 / 45

Which of the following statements regarding mass scaling in an explicit dynamic analysis are correct? Select the two best options.

10 / 45

Which of these properties dissipates energy from a system? Select the best option.

11 / 45

Which of the following statements is relevant to using a full method in a harmonic analysis? Select the best option.

12 / 45

Consider two masses connected by a single spring, and the masses are only allowed movement in a single direction (1D). How many natural frequencies are there in this system?

13 / 45

Which of the following is true for participation factor and effective mass?

14 / 45

In many cases, modes with frequencies much higher than those of the excitation are neglected because _____. Select the option that best completes the sentence.

15 / 45

The coefficients used for combination of modes in a mode superposition method are called _____? Select the best option.

16 / 45

Which three statements are correct about time integration methods?

17 / 45

For a response spectrum analysis, the mode superposition method is _____. Select the best option.

18 / 45

A tensile stress state in a pre-stressed modal analysis will tend to _____. Select the best option to complete the sentence.

19 / 45

Stress analysis of a part subjected to known, cyclical thermal loads can be performed using a _____. Select the best option to complete the sentence.

20 / 45

A person steps onto a slender wooden plank and begins to oscillate up and down, and eventually the oscillatory motion stops. Which mechanism best models this real world example?

21 / 45

Which of the following holds true for a cantilever (such as a diving board) excited by a harmonic external force with its frequency matching the second natural frequency? Select the best option.

22 / 45

Which of these NEED NOT be a linear dynamic analysis?

23 / 45

To maintain numerical stability while using the explicit time integration method, the time-step size should satisfy the CFL condition, which is $\Delta t \leq f \left ( \frac{h}{c} \right )$. Which of the following statements are correct about the CFL condition? Select the two best options.

24 / 45

The damping ratio is defined as:

25 / 45

Imagine a body of mass m is resting on a platform of mass $M$. Assuming that there is no friction between them, if we set the platform into motion from rest to a constant velocity, $V$, over a time $T$, what will be the net acceleration of the body?

26 / 45

If a machine component undergoes small, elastic deformations due to time-dependent loads, which analysis is preferred to study such a system?

27 / 45

Which of the following statement is relevant to using the mode superposition method in a harmonic analysis? Select the best option.

28 / 45

Performing a harmonic analysis can serve to _____. Select the two best options.

29 / 45

Which expression characterizes the phase angle of a complex variable?

30 / 45

Which analysis is suitable to calculate the stresses developed in a steam turbine blade due to constant, high-speed rotation?

31 / 45

Which of these are correct statements about time intgeration methods? Select the two best options.

32 / 45

A mountain bike has a fluid filled shock absorber with a piston moving in the contained fluid. With regard to the energy dissipation from the damping, one can expect which of the following?

33 / 45

The velocity derived from the complex displacement function is characterized by which expression?

34 / 45

A large amplification factor Q is associated with a:

35 / 45

A car is driving at a constant velocity, and the brakes are applied suddenly to stop the car. Which type of physical damping phenomena dominates the energy dissipation due to the braking?

36 / 45

While simulating the drop test of a circuit board on to a hard ground using an explicit analysis, if the computing time is very long, which of the following options may help reduce the computational time? Select the three best options.

37 / 45

The peak magnitude of the forcing excitation is typically referred to as _____. Select the best option.

38 / 45

The imposed circular frequency in a harmonic analysis is represented by which of the following formulas.

39 / 45

A continuous system will have how many natural frequencies?

40 / 45

In the Rayleigh damping equation, how does increasing frequency affect the contribution from the mass and stiffness terms to the damping ratio? Pick the two correct responses.

41 / 45

When we clamp and hold a viscoelastic material sample under a constant amount of displacement, what phenomenon do we expect to see?

42 / 45

Damping, and the associated rate of energy dissipation, can be a function of which of these? Pick the three best options.

43 / 45

Which type of analysis is preferred if we wish to study the stresses developed in an electronic device mounted on a moving car's dashboard?

44 / 45

How can one identify the most important natural frequencies & modes for an excitation in a given direction? Select the best option.

45 / 45

Harmonic analysis is also referred to as _____. Select the best option.