.q 1 0
Fiber volume fraction is defined as
.
.a a.	Volume of Fibers/Volume of Matrix.
.a b.	Volume of Fibers/Volume of Composite.
.a c.	1 plus the Matrix Volume Fraction.
.a d.	Volume of Composite/Volume of Fibers
.A 2
.R
The fiber volume fraction is the defined as the volume of fibers divided by the volume of the composite
.

.q 2 0
The change of properties for a corresponding 1 percent increase in void content is in the range of
.
.a a.	2 to 10 percent.
.a b.	less than 2 percent.
.a c.	2 to 15 percent.
.a d.	greater than 15 percent.
.A 1
.R
The change of properties for a corresponding 1 percent increase in void content is in the range of 2 to 10 percent
.

.q 3 0
The maximum fiber volume fraction for circular fibers in a square array is
.
.a a.	70.23 percent.
.a b.	90.69 percent.
.a c.	78.54 percent.
.a d.	86.93 percent.
.A 3
.R
The maximum fiber volume fraction for circular fibers in a square array is 78.54 percent
.

.q 4 0
The maximum fiber volume fraction for circular fibers in a hexagonal array is
.
.a a.	78.54 percent.
.a b.	90.69 percent.
.a c.	70.23 percent.
.a d.	86.93 percent.
.A 2
.R
The maximum fiber volume fraction for circular fibers in a hexagonal array is 90.69 percent
.

.q 5 0
Concerning the Halphin-Tsai equations for transverse elastic modulus, the reinforcing factor depends on
.
.a a.	Young's modulus of the fibers.
.a b.	Young's modulus of the matrix.
.a c.	fiber volume fraction.
.a d.	packing geometry.
.A 4
.R
Concerning the Halphin-Tsai equations for transverse elastic modulus, the reinforcing factor depends on the packing geometry
.

.q 6 0
The volume fraction of voids is generally determined by
.
.a a.	burn or acid digestion tests.
.a b.	tension tests.
.a c.	impact tests.
.a d.	purely analytical means.
.A 1
.R
The volume fraction of voids is generally determined by burn or acid digestion tests
.

.q 7 0
Volume fraction of voids is given by
.
.a a.	(theoretical minus experimental composite density)/theoretical composite density.
.a b.	(theoretical minus experimental composite density)/experimental composite density.
.a c.	void volume/(fiber volume plus composite volume).
.a d.	(experimental minus theoretical composite density)/experimental composite density.
.A 1
.R
Volume fraction of voids is given by the (theoretical minus experimental composite density)/experimental composite density 
.

.q 8 0
Bending moment per unit width is inversely proportional to the 
.
.a a.	square of the thickness.
.a b.	cube of the thickness.
.a c.	mass.
.a d.	square of the mass.
.A 1
.R
Bending moment per unit width is inversely proportional to the square of the thickness
.

.q 9 0
For a laminate to be safe, the strength ratio in each ply must be
.
.a a.	less than 1.
.a b.	greater than 1.
.a c.	equal to zero.
.a d.	not equal to zero.
.A 2
.R
For a laminate to be safe, the strength ratio in each ply must be greater than 1
.

.q 10 0
If the stress intensity factor is greater than the critical stress intensity factor for a material then
.
.a a.	the material is safe.
.a b.	the strain energy is less.
.a c.	the fracture will grow catastrophically.
.a d.	none of the above.
.A 3
.R
If the stress intensity factor is greater than the critical stress intensity factor for a material then the fracture will grow catastrophically
.

.q 11 0
The facing materials in sandwich plates are made of 
.
.a a.	high strength materials.
.a b.	low strength materials.
.a c.	brittle materials.
.a d.	soft materials.
.A 1
.R
The facing materials in sandwich plates are made of high strength materials
.

.q 12 0
The key factor to changing the stacking sequence is to do the following with the inter-lamina shear stress without increasing the tensile inter-lamina normal stress
.
.a a.	Increase.
.a b.	Decrease.
.a c.	Maintain uniform.
.a d.	None of the above.
.A 2
.R
The key factor to changing the stacking sequence is to decrease the inter-lamina shear stress without increasing the tensile inter-lamina normal stress
.

.q 13 0
When a crack develops in an isotropic material the stresses at the crack tip are
.
.a a.	cannot be found.
.a b.	equal to zero.
.a c.	equal to one.
.a d.	infinite.
.A 4 
.R
When a crack develops in an isotropic material the stresses at the crack tip are infinite
.

.q 14 0
In a ceramic matrix material, generally matrix breaks precede fiber breaks
.
.a a.	True.
.a b.	False.
.A 1
.R
In a ceramic matrix material, generally matrix breaks precede fiber breaks
.

.q 15 0
The shear forces are maximum at which location in the sandwich panel requiring the core to support shear?
.
.a a.	on the top.
.a b.	on the bottom.
.a c.	in the middle.
.a d.	on the surface.
.A 3
.R
The shear forces are maximum in the middle of the sandwich panel requiring the core to support shear
.

.q 16 0
The longitudinal modulus of a lamina is dependent on
.
.a a.	fiber Young's modulus.
.a b.	matrix Young's modulus.
.a c.	fiber volume fraction.
.a d.	all of the above.
.A 4
.R
The longitudinal modulus of a lamina is dependent on fiber Young's modulus, matrix Young's modulus, and the fiber volume fraction
.

.q 17 0
Longitudinal modulus of a lamina is greater than
.
.a a.	fiber and matrix Young's modulus.
.a b.	matrix Young's modulus if it is less than the fiber Young's modulus.
.a c.	fiber Young's modulus if it is greater than the matrix Young's modulus.
.A 
.R

.

.q 18 0
Generally for polymer matrix composites, the maximum strain to failure is greater for
.
.a a.	the fiber.
.a b.	the matrix.
.a c.	they are equal.
.A 2
.R
Generally for polymer matrix composites, the maximum strain to failure is greater for the matrix
.

.q 19 0
Strength ratio is defined as
.
.a a.	load which can be applied before failure.
.a b.	load which can be applied before failure divided by the load applied.
.a c.	load which can be applied before failure divided by the longitudinal Young's modulus.
.A 2
.R
Strength ratio is defined as load which can be applied before failure divided by the load applied.
.

.q 20 0
The Tsai-Wu failure theory gives a more accurate prediction of failure criterion because 
.
.a a.	it does not predict the mode of failure.
.a b.	it accounts for all the stresses and strengths.
.a c.	it needs a sophisticated computer program to produce the results.
.A 
.R

.

.q 21 0
Unidirectional composites are tested because
.
.a a.	they are easy to manufacture.
.a b.	they are used in most applications.
.a c.	the results can be directly used to predict behavior in an off-axis lamina.
.A 3
.R
Unidirectional composites are tested because the results can be directly used to predict behavior in an off-axis lamina and multidirectional laminates.
.

.q 22 0
If the applied stress is greater than the longitudinal tensile strength, for which volume fraction of fibers is it possible for the composite to take a greater load?
.
.a a.	critical fiber volume fraction.
.a b.	minimum fiber volume fraction.
.a c.	maximum fiber volume fraction.
.A 2
.R
The minimum volume fraction
.

.q 23 0
Poor bonding between the fiber and matrix results in
.
.a a.	a decrease in the composite transverse strength.
.a b.	an increase in the composite transverse strength.
.a c.	no change in the composite transverse strength.
.A 1
.R
Poor bonding between the fiber and matrix results in a decrease in the composite transverse strength
.

.q 24 0
For a lamina exposed to changes in temperature, it is generally assumed that
.
.a a.	the change in temperature is the same for the fiber and the matrix.
.a b.	the change in temperature is greater in the matrix than in the fiber.
.a c.	the change in temperature is greater in the fiber than in the matrix.
.A 1
.R
For a lamina exposed to changes in temperature, it is generally assumed that the change in temperature is the same for the fiber and the matrix
.

.q 25 0
For polymeric composites exposed to a change in moisture, the moisture concentration in the fibers is generally
.
.a a.	greater than zero.
.a b.	less than zero.
.a c.	close to zero.
.A 3
.R
For polymeric composites exposed to a change in moisture, the moisture concentration in the fibers is generally close to zero
.

.q 26 0
For composites with high fiber to matrix moduli ratios, the longitudinal coefficient of moisture expansion is
.
.a a.	greater than the transverse value.
.a b.	less than the transverse value.
.a c.	equal to the transverse value.
.a d.	zero.
.A 4
.R
For composites with high fiber to matrix moduli ratios, the longitudinal coefficient of moisture expansion is zero
.

.q 27 0
The three most common types of fibers used in composites are glass, aramids, and graphite.  Of these, which are transversely isotropic?
.
.a a.	glass and graphite.
.a b.	glass and aramids.
.a c.	aramids and graphite.
.A 3
.
.R
The three most common types of fibers used in composites are glass, aramids, and graphite.  Of these, aramids and graphite are transversely isotropic

.

.q 28 0
For a composite under a transverse tensile load, a weak fiber-matrix bond
.
.a a.	may decrease the longitudinal tensile strength.
.a b.	may increase the longitudinal tensile strength.
.a c.	has no effect on the longitudinal tensile strength.
.A 2
.R
For a composite under a transverse tensile load, a weak fiber-matrix bond may increase the longitudinal tensile strength
.

.q 29 0
The component in a polymeric matrix component which carries the largest percentage of the applied load is
.
.a a.	the fibers.
.a b.	the matrix.
.a c.	Neither, the fiber and matrix share the load equally.
.A 1
.R
The component in a polymeric matrix component which carries the largest percentage of the applied load is the fibers
.

.q 30 0
Adding more fibers to a matrix
.
.a a.	increases the ultimate tensile strength of the composite compared to the matrix.
.a b.	decreases the ultimate tensile strength of the composite compared to the matrix.
.a c.	has no effect.
.A 2
.R
Adding fibers to a matrix decreases the ultimate tensile strength of the composite compared to the matrix
.

.q 31 2
What do you think of this test?
.
.a 8 60
.A kaw@eng.usf.edu