You are a failure analysis engineer who must certify the integrity of an engineering component. Your component manufacturer has informed you that the plane strain fracture toughness of the component is measured to be as high as 140 ???√? and certifies that the surface cracks observed in the components are not bigger than 0.01 mm. During service, this component is to be continuously cycled at 3000 revolutions per minute between compressive and tensile stresses of 350 MPa. Assume that ? = 1.12 for all possible surface cracks. Materials constants are ? = 3.4 and ? = 2 × 10^−15 .

(a) You have access to three non-destructive testing techniques as shown in the table below. By calculating the critical crack length required to cause fracture, determine if any of the three techniques can be used to detect the crack before the fracture of the component.

(b) If you are to remove the component as soon as the crack length reaches 55% of the critical crack length to cause fracture, determine how many useful hours of the life of this component remains.

The sustainability or waste triangle is (in order of most important to last resort):

Recycle, reuse, reduce
Reduce, reuse, recycle
Reuse, reduce, recycle
Reduce, recycle, reuse

Redundancy in the leachate collection system is important. Pick all the reasons why.

Mechanical failures
Drought
Regular maintenance
Electrical outages

. If you know the difference in enthalpy (h) of the supply air and the room air, how could you use this to determine the required amount of supply air to condition for a heat loss or a heat gain?

What are the two preferred ways to supply air into a perimeter space to heat and cool the space?

What is the appropriate name for a residential hot air heating unit?

Construction Code

Methods of dispute resolution:

Discuss the advantages and disadvantages of resolving disputes through the court system.

An existing 36-inch diameter concrete gravity sewer installed on a slope of 0.25% currently conveys a peak flow rate of 12 cfs. A builder proposes to connect a new residential development to this existing sewer. Projected peak flow from this new development is 4 cfs.

a) Depth of flow in sewer before new development is connected

b) Depth of flow in sewer after new development is connected

c) Flow velocity in sewer after new development is connected

d) Flow type (critical, subcritical or supercritical) after new development is connected

e) Diameter of a sewer to convey combined peak flow of 16 cfs if maximum allowable D/d is 0.85 (i.e. assume you are designing new sewer on the same 0.25% slope)

1. The ordinates of a hydrograph at a section of a stream having a drainage area of 81 km² are given below. Find the unit hydrograph assuming the base flow equal 18 m³/s.

A simple floor girder with a span 20 ft has a tributary width of 20 ft. The nominal loads that act on the floor system are shown below. Using the ASCE 7 Strength Design load combinations determine the factored design load in the beam (plf). Show all load combination calculations and identify the controlling load combination and resulting design values for positive and negative moment (±Mu) and shear (Vu).

Nominal Loads

(See Fluids in the News article titled “Modeling parachutes in a water tunnel”.) Flow characteristics for a 35-ft-diameter prototype parachute are to be determined by tests of a 1.0-ft-diameter model parachute in a water tunnel. Some data collected with the model parachute indicate a drag Fm = 22 lb when the water velocity is 4 ft/s.
(a) Find the predictor equation. Assume the drag to be a function of the velocity, V, the fluid density, ρ, and the parachute diameter, D. Note that model variables have subscripts m.

(b) Use the model data to predict the drag on the prototype parachute falling through air at 10 ft/s.

A traffic engineer needs to determine the AADT on a rural primary road that has the volume distribution characteristics shown in the following tables. He collected the following data on a Wednesday during the month of August. What is the estimated AADT of the road using following information (Traffic volume, HEF, DEF, and MEF factors)? (6.5 points)?

A 1150 veh/day

B 5438 veh/day

C 5590 veh/day

D 7250 veh/day

E None of the above

A 4-m-high and 6-m-wide wall consists of a long 18x30 cm2 cross section of horizontal bricks (K=0.72W/mC) separated by 3-cm-thick plaster layer (K=0.22W/mC). There are also 2-cm-thick plaster layers on each side of the wall, and a 2-cm-thick rigid form (K=0.026W/mC) on the inner side of the wall. The indoor and outdoor temperatures are 22C and -4 C, and the combined convection and radiation heat transfer coefficients on the inner and outer walls are 10W/m2C and 20W/m2C, respectively. Determine the rate of heat transfer through the wall

1. What are some advantages and disadvantages of the general contract approach? Assume that the general contact will be awarded on the basis of competitive lump sum bidding.

2. What are the possible options and how a contracting method is selected for a federal-aided highway project?

For a channel with subcritical flow condition, a bridge opening constriction produces a reduction of about 10% of the original channel width due to the structural elements. Therefore, hydraulically speaking, the water is accelerated at the opening and its water depth is lower than the water depth from the upstream bridge. True or False? Explain.