Finite Element Method Questions and Answers Part-12

1. Each triangle formed by three nodes and three sides is called a ______
a) Node
b) Force matrix
c) Displacement vector
d) Element

Answer: d
Explanation: An element is a basic building block of finite element analysis. An element is a mathematical relation that defines how the degrees of freedom of a node relate to next. In discretization of 2D element each triangle is called element.

2. The finite element method is used to solve the problem ______
a) Uniformly
b) Vigorously
c) Approximately
d) Identically

Answer: c
Explanation: The finite element method is a numerical method for solving problems of engineering and mathematical physics. Typical problems areas of interest include structure analysis, heat transfer, fluid flow, mass transport and electromagnetic potential etc..,. The method yields approximate values of the unknowns at discrete number of points.

3. In two dimensional modeling each node has ____ degrees of freedom.
a) One
b) Infinity
c) Finite
d) Two

Answer: d
Explanation: In two dimensional problem, each node is permitted to displace in the two directions x and y. Thus each node has two degrees of freedom.

4. For a triangular element,element displacement vector can be denoted as ___
a) q=[q1,q2,q3]T
b) q=[q1,q2]T
c) q=[q1,q2,……q6]T
d) Load vector

Answer: c
Explanation: The displacement components of a local node is represented in x and y directions, respectively. For that we denote element displacement vector as
q=[q1,q2,……q6]T.

5. In two dimensional analysis, stresses and strains are related as ___
a) σ=Dε
b) σ=ε
c) Load values
d) ε=Dσ

Answer: a
Explanation: When a material is loaded with force, it produces stress. Which then cause material to deform. Strain is response of a system t an applied stress.

6. In two dimensional modeling, body force is denoted as ___
a) f=[fx,fy]T
b) σ=Dε
c) q=lq
d) f=[2|i-j|+1]

Answer: a
Explanation: A body force is a force that acts throughout the volume of the body. Body forces contrast with contact forces or the classical definition of surface forces which are exerted to the surface of the object. Body force is denoted as
f=[fx,fy]T.

7. The information of array of size and number of elements and nodes per element can be seen in ___
a) Column height
b) Element connectivity table
c) Matrix form
d) Undefined

Answer: b
Explanation: An element connectivity table specifies global node number corresponding to the local node element. Element connectivity is the nodal information for the individual element with details how to fit together to form the complete original system.

8. In two dimensional modeling, traction force is denoted as ____
a) Row vector
b) T=[Tx,Ty]T
c) f=[fx,fy]T
d) σ=Dε

Answer: b
Explanation: Traction or tractive force is the force used to generate motion between body and a tangential surface, through the use of dry friction, through the use of hear force. Tractive force is defined as
T=[Tx,Ty]T

9. In two dimensional modeling, elemental volume is given by ____
a) dV=tdA
b) dV=dA
c) f=[fx,fy]T
d) Trussky program

Answer: a
Explanation: In mathematics, a volume element provides a means for integrating a function with respect to volume in various co-ordinate systems such as spherical co-ordinates and cylindrical co-ordinates. Then elemental volume is given by
dV=tdA.

10. Finite element method uses the concept of _____
a) Nodes and elements
b) Nodal displacement
c) Shape functions
d) Assembling

Answer: c
Explanation: The finite element method is a numerical method for solving problems of engineering and mathematical physics. Finite element method uses the concept of shape functions in systematically developing the interpolations.