(c) Draw a schematic graph of resolved shear stress versus shear strain for a single crystal of a pure metal. Clearly label the point of the critical resolved shear stress and the three subsequent stages of dislocation behaviour. Describe these three stages.
(d) Explain why the critical resolved shear stress is much lower than the theoretical strength, based on the force required to break atomic bonds within the structure.
In: Mechanical Engineering
5 example in industrial
-valve in i/c engine
In: Mechanical Engineering
What distinguishes scientific and experiential disciplines?
| a) | Science is based on facts and is always right and cannot be falsifiable |
| b) | Scientific disciplines are more difficult to understand, teach and learn |
| c) | Experiential disciplines do not use the scientific process |
| d) | Experiential disciplines are based on standards and best practices and lack overarching principles, laws or axioms that can be applied to solving a wide variety of problems |
| e) | All of the above |
| f) | a and b only |
| b and d onl |
In: Mechanical Engineering
One end of the straw is blocked by a finger when You pushed the other side of straw under water h_0 (m) and right after that finger is removed from end of straw. You can see the level of water in the straw is rising. Find the depth of water in the straw h(t). Consider the situation as quasi equillibrium state and neglect the surface tension.
In: Mechanical Engineering
# sensors for process nonitoring : cutting process ..
- Briefly explain the process ( first explain it un general and then related with the sensor)
-- I need it typing and clear and at least 2 pages
In: Mechanical Engineering
In Finite Element Analysis (FEA) What is a local stiffness matrix and a global stiffness matrix?
In: Mechanical Engineering
Draw a simple circuit to open and close a double acting hydraulic cylinder.
In: Mechanical Engineering
Q11 a) What is the basis for piston rod design? Explain the significance of area ratio.
b) List 4 of the likely causes for slow or erratic motion of an actuator in a hydraulic equipment.
In: Mechanical Engineering
Mechanical vibration.
Examples of forced damped oscillation with harmonic force.
In: Mechanical Engineering
An oven may be regarded as a cube, each side 1.2m long. The oven stands on thin legs and the heat transfer through each of the six faces is identical. The walls and doors are all made of a stainless steel lining (thermal conductivity 20W/mK) 2mm thick, a layer 75mm thick of insulating material (thermal conductivity 0.25W/mK) and a mild steel outer sheet (thermal conductivity 48.5W/mK) 3mm thick. If the inner wall temperature is 400oC and the outer surface temperature is 100oC calculate the rate of heat loss from the oven. Estimate the heat transfer coefficient between the oven and the surrounding air at 30oC
[8.63kW, 14.3W/m2K]
In: Mechanical Engineering
In: Mechanical Engineering
In the Injection Moulding Process, thicker parts are more susceptible to shrinkage. Explain why this is the case.
In: Mechanical Engineering
This is problem 5-5 from El-Wakil’s Powerplant Technology book -- steam expands ideally in a turbine from 2500 psia and 1000 degFahrenheit to 1 psia. Compare the maximum steam velocities and the number of stages required by (a) a velocity-compounded impulse turbine, (b) a pressure-compounded impulse turbine, and (c) a 50 percent reaction turbine if the optimum blade velocity may not exceed 885 ft/s in any of them. Take all nozzle angles to be 25°.
In: Mechanical Engineering
A CAT D&H (power-shift) dozer is used to push material that weights 87 pcf in the bank state. It is estimated that the material will swell 5% from a bank state. The material is in a loose stock pile and is to be moved an average distance of 250 ft on a 2% downhill grade. The operator is average. Job efficiency is estimated to be at a 50-min hour. Assume that the dozer will have an 0.39 coefficient of traction. The O&O cost for the dozer is $86 per hour and the operator's wage is $17.50 per hour plus 44% for fringes, insurance and worker's compensation. Calculate the production in bcy per hour. (Reference Table 7.2 and Figure 7.13)
TABLE 7.2 Caterpillar job condition correction factors for
estimating dozer production
Track-type tractor Wheel-type tractor
Operator
Excellent 1.00 1.00
Average 0.75 0.60
Poor 0.60 0.50
Material
Loose stockpile 1.20 1.20
Hard to cut; frozen
with tilt cylinder 0.80 0.75
without tilt cylinder 0.70 —
cable-controlled blade 0.60 —
Hard to drift; “dead” (dry, noncohesive 0.80 0.80
material) or very sticky material
Rock, ripped or blasted 0.60–0.80 —
Slot dozing 1.20 1.20
Side-by-side dozing 1.15–1.25 1.15–1.25
Visibility
Dust, rain, snow, fog, or darkness 0.80 0.70
Job efficiency
50 min/hr 0.83 0.83
40 min/hr 0.67 0.67
Direct-drive transmission
(0.1-min fixed time) 0.80 —
Bulldozer*
Adjust based on SAE capacity relative
to the base blade used in the estimated
dozing production graphs
Grades—see the graph
In: Mechanical Engineering
Using the given lead-tin phase diagram for an alloy content of 80 wt % Sn and a temperature of 100 C (a) what is the primary phase (b) what are the mass fractions of eutectic and primary phases? Show tie line used and all calculations. Use standard lead-tin phase diagram.
In: Mechanical Engineering