ASSESSMENT for Part 1
Outcome/Grade / Criteria/
Descriptors / Evidence / Feedback / Assess / IV
Pass Assessment
1. Analyze static engineeringsystems / 1. determine distribution of shear force, bendingmoment and stress due to bending in simplysupported beams / Draw SF and BM diagrams by hand or equation graphic, etc.
Beam section is selected against given data.
2. select standard rolled steel sections for beams andcolumns to satisfy given specifications / The slenderness ratio, Euler buckling, and the stress are determined correctly.
The safety of materials isexplained.
3. determine the distribution of shear stress and theangular deflection due to torsion in circular shafts / The maximum transverse shear stress in the shaft and the angular deflection of the shaft are determined correctly.
2. Analyze dynamicengineering systems / 1.determine the behavior of dynamic mechanicalsystems in which uniform acceleration is present / The acceleration of the car and the time that the caruses to get to the point are determined correctly.
2. determine the effects of energy transfer inmechanical systems / The speed of the car in point F is determined correctly.
3. determine the behavior of oscillating mechanicalsystems / The number of times that light is blocked is decided correctly.
Grading Assessment
M1 / Apply strategies to find an appropriate solution to the given problem. / Effective approach has been Applied tosolve problem, such as the BM maximum is determined, etc.
M2 / Apply appropriate methods and techniques to solve problems. / Series of relevant theories and techniques have been Applied toproperly solve problems.
Draw BM diagrams by Excel or Sketchpad, etc.
M3 / Present and Communicate appropriate findings / The comments are structured and clear, and data diagrams processed by numerical control system, etc.
D1 / Use critical reflection to evaluate own work / There is evaluation in assignment that explains solutions’ advantages and disadvantages.
D2 / Take responsibility for managing and organizing activities / Activities havebeen planned, managed and organized, independence has been demonstrated, or the importance of teamwork is recognized and exemplified.
There is no delay work.
D3 / Demonstrate convergent and creative thinking / Multiplecomputational solutions or graphical solution or different option strategies are present and evaluated.
Receptiveness to new ideas is evident.
Creative thinking is shown in solving problems
Assessor’s additional comments
Assessor’s signature:
Student’s Feedback
Student’s signature:
ASSESSMENT for Part 2
Outcome/Grade / Criteria/
Descriptors / Evidence / Feedback / Assess / IV
Pass Assessment
3. Apply DC and AC theory / 1. solve problems using DC electrical principles / The circuit diagrams are selected properly, andtheresistance value is given rightly.
2. recognize a variety of complex wave forms andexplain how they are produced from sinusoidalwave forms / Dawn out the block diagram and the output of the oscillograph in each step respectively.
3.apply AC theory to the solution of problems onsingle phase R, L, C circuits and components / Write down the voltage expressions of the inductance, equivalent resistance and equivalent inductance rightly.
4. apply AC theory to the solution of problems on transformers / Determine how many rounds each secondary should coil has properly.
4. Investigate information andenergy control systems / 1. describe the method by which electrical signalsconvey information / Select strategies of installation and dawn a block diagram correctly.
2. describe the methods by which electrical signalscontrol energy flow / The overload alarm unit is added properly and the banks are filled rightly.
3. select and interface system components to enablechosen system to perform desired operation / The circuit is connected rightly. The names of the units are marked and the main reasons are given properly.
Grading Assessment
M1 / Apply strategies to find an appropriate solution to the given problem. / Theory to the exploration of complex problems with multiple variables is applied and effective judgments are made.
M2 / Apply appropriate methods and techniques to solve problems. / Appropriate methods and resources have been Selected to process complex data.
M3 / Present and Communicate appropriate findings / The comments are structured and clear.
D2 / Take responsibility for managing and organizing activities / Activities havebeen planned, managed and organized, autonomy or independence has been demonstrated, or the importance of teamwork is recognized and exemplified.
There is no delay work.
Assessor’s additional comments
Assessor’s signature:
Student’s Feedback
Student’s signature:
Assignment Description
Scenario:
Construct a hoisting apparatus (including controllingand illuminating system) at Renhua Iron Mine with I-Beams shown in Diagram 1. To move the ore out of the mine, a mining car filled with iron ore would slip from Point G to Point F; then the hoisting apparatus would lift the car up and move horizontally along the top I-Beam which serves as a lead rail. The structural drawing is shown below. Electric windlass 1 is installed in the carriage to lift the car; electric windlass 2 is installed in the column to move the car horizontally.
Diagram 1
Part 1
Task1(Pass Criterion1.1)
Determine distribution of shear force, bending moment and stress due to bending in simply supported beams. A loaded and simply supported W8×58 I-beam is shown in Diagram 1. Where AB = 0.6m., BC = 8.0m., CD = 3.0m., DE = 3.0m.. Suppose point B is the mass centre and geometrical center of the carriage and the cargo, and the weight of I-beam can be neglected. The mining car filled with iron ore weights 1000～1500kg together. The distributed force of the weight equalizer on the right is 10000kg/m. Please draw the shear force diagram and the bending moment diagram, determine the maximum bending moment and the bending stresses at that location. The beam characteristics may be found in the I-Beam Data.
Note: the weight of the mining car filled with iron is confirmed the last number of your student’s Reg.
I-Beam Data：
Hints:Step 1: Determine holding forces Cy and Ey.
Step 2: Determine the equation of Shear force.
Step 3: Determine the equation of Bending moment.
In equation a and C are constants, the integration constant C can be determined by boundary condition.
Step 4：Draw the distribution of shear force and bending moment.
Step5: Determine the maximum bending moment and bending stresses with graphic method.
Note:
Task2 (Pass Criterion1.2)
Select standard rolled steel sections for beams and columns to satisfy given specifications. A 25 ft. long ASTM-A36 steel, W8×58 I-Beam is selected to be the column of the hoisting apparatus with fixed-free ends. For this column, determine the slenderness ratio, the load that will result in Euler buckling, and the associated Euler buckling stress and determine whether the results can satisfy the given specifications as task1 or not. The beam characteristics may be found in the I-Beam Data.
Task3 (Pass Criterion1.3)
Determine the distribution of shear stress and the angular deflection due to torsion in circular shafts. Diagram 2 has shown the structure of the carriage. The reel and the brake which are made from thin walled tube are welded together with the shaft. The solid shaft with a driving external torque MR at right end is turning. The mining car filled with iron ore which weights 1000～1500kg is moving up with constant speed. The brake not operates. If all frictions are neglected, please determine the maximum transverse shear stress in the shaft due to the applied torque and the angular deflection of the middle shaft (Gsteel = 12×106 lb/in2 ). Where, d1=2in., d2= 6in., d3=10in., L1=1ft., L2=0.5ft. , L3=0.5ft. , L4=1ft., L5=1ft., L6=1ft..
Diagram 2
Task4 (Pass Criterion2.1)
Determine the behavior of dynamic mechanical systems in which uniform acceleration is present. The mining car filled with iron ore weights1000～1500kg together and was pushed from Point G to Point F. The car starts with the velocity of 0. The friction factor of the car and the railμ=0.1. In the diagram 1, w=3m, h2=0.5m. Please determine the acceleration (a) of the car and the time (t) that the car uses to getto Point F.
Task5 (Criterion2.2)
Determine the effects of energy transfer in mechanical systems and the behavior of oscillating mechanical systems. The mining car filled with iron ore weights 1000～1500kg together. The car starts with the velocity of 0m/s. When the car reaches Point F, the car would perform damped oscillation. In the diagram, w=3m, h2=0.5m. Supposed the work done by gravity is 20 times as big as the work done by friction. Please determine the speed of the car in point F.
Diagram 3
Task6 (Pass Criterion2.3)
Determine the behavior of oscillating mechanical systems. Set up a light source and photoelectric door at Point F (Diagram 4). If the shape of the rail is a part of a circle, the behavior of the car around Point F is underdamped oscillation. If length of the equivalent simple pendulum L=6m, the Damping Factor of the systemβ = 0.33< angular frequency, the curve of damped oscillation shown as Diagram 5, please try to reach a simple conclusion about the β’s influence on the system. If the width of the car is 1m, w=3m, h2=0.5m, the work done by gravity is much bigger than the work done by friction. Please decide the number of times that light is blocked.
Diagram 4
Diagram 5(a) Diagram 5(b)
Part 2
Task1(Pass Criterion3.1)
Solve problems using DC electrical principles. For safety and technology reasons, the voltage of the control circuit of the relay which controls the hoisting engine is 24VDC. Suppose only 36VCD power source, a 300Ωresistance, a resistance R, a button, a normal closed contact, a normal open contact and a relay (Open frame relay, 24VDC,300Ω coil,2 normally open, 2 normally closed 480 VAC, 3 amps) are available. Please classify the following circuit diagrams, find out the best one and calculate the resistance value ofresistance R.
Diagram1 /
Diagram 2 /
Diagram3
Diagram 4 /
Diagram5 /
Diagram6
Circuit / Whether or not the circuit work properly？ / Class
1
2
3
4
5
6
The best circuit
The value ofresistance R and calculation method
Task 2(Pass Criterion3.2)
Recognize a variety of complex wave forms and explain how they are produced from sinusoidal wave forms.There are 5 signal sources, 4 phasers, a summator and an oscillograph to do an experiment of complex wave forms. The main experimental procedures：
1) The oscillograph output voltage from the summator, which is proportional to A+u1(t)+ u3(t)+ u5(t)+ u7(t), into the Y axis. Input the sine waves to the summator one by one.
2) Adjust the phases to make sure that u1 and u3 should be out-phase with the initial phases while u1 and u5 should be in-phase with the initial phases, and u1 and u7 should be out-phase with the initial phases.
3) Adjust the amplitude ratio of the 4 sine waves to be 1 : 1/32 : 1/52 : 1/72.Finally the approximate triangle wave can be observed.
Try to
1) Dawn out the block diagram representation of triangle waveform composed
2) Dawn out the output of the oscillograph in each step respectively.
Task 3(Pass Criterion3.4, 3.3)
Apply AC theory to the solution of problems on transformers.Apply AC theory to the solution of problems on single phase R, L, C circuits and components.
1) Here are three step-down transformers: T1, T2, and T3. If we need to transform the voltage from 380V to 48V and 230V respectively, try to complete the circuit Diagram 7. If T1s’ and T2s’primary coil has 3800 rounds, then please determine how many rounds each secondary should coil has.
Diagram 7
2) Here is a monophase transformer (4kVA, 380/220V), If voltage variation and open circuit current can be neglected, it powers 20 fluorescent lamps (220V, 40W, cosφ=0.5).Provide the solution of problems on the currents of the primary coil(I1) and the secondary coil(I2). If the circuit of fluorescent lamp can be equivalent toRL series circuit, write down the voltage expressions of the inductance, equivalent resistance and equivalent inductance.
Task 4 (Pass Criterion4.1)
Describe the method by which electrical signalsconvey information.In order to weigh the ore in the car, Strain Gage is introduced to make the converter. There are three specific kinds of Strategies to set up the converter: under the mining car, on the lifting hook or on the I-beam.
1) The diagram below shows 6 strategies of installation. Please mark out the correct strategies. Choose the best strategy and give two main reasons.
2) Dawn a block diagram of the weightier and mark out the correspondingphysical quantities (for example, axialrelative deformationε, ResistancevariationΔR, etc.)
Strategy 1 / Strategy3
Strategy4
Strategy2 /
Strategy5 /
Strategy6
Correct installation is:Strategy 1 , 2 , 3 , 4 , 5 , 6 .
What is the best strategy of the installation? Give two main reasons briefly.
(1)
(2)
The block diagram of the weightier
Task 5 (Pass Criterion4.2)
Describe the methods by which electrical signalscontrol energy flow.
1) Thecircuit shown below controls the horizontal movement of a mining car. The normal open contact J3 in the circuit would react while the contact J0 or J1 or J2 is activated. The electric belland trouble lamp’s working voltage is 36VDC. Please add the overload alarm unit to the system andcomplete this circuit. Here J1 andJ2 is the left over travel contact and right over travel contact.
2) The set of action in the tableis to be performed sequentially, please fill in the blanks.
Diagram 8
What action / A series of action will be activated after the action1 / No action
2 / M1→ (C1C/ C1O/3normal open contacts of M1)→(Motor/M3)
3 / No action
4 / M1→(C1C/ C1O/3normal open contacts of M1)→(Motor/M3)
5 / M2→(C2C/ C2O/3normal open contacts of M2)→(Motor/M3)
6a / J0→( M2/ C2C/ C2O/3normal open contacts of M2) → (Motor/M3)
6b / J1→( M2/ C2C/ C2O/3normal open contacts of M2) → (Motor/M3)
6c / J2→( M2/ C2C/ C2O/3normal open contacts of M2) →(Motor/M3)
6d / J3→( M2/ C2C/ C2O/3normal open contacts of M2) →(Motor/M3)
Task 6 (Pass Criterion4.3)
Select and interface system components to enablechosen system to perform desired operation. The hoisting apparatus should be able to tell whether there is a mining car in position. Here are five plans: use photodiodeonly (P), use strain gage only (S), use reed switch only (R), photodiode andstrain gage together (PS), photodiode and reed switch together (PR).
Please try to:
1) Dawn lines to connect the units
2) Mark out the names of the units
3) Fill in the blank of the table with the evaluation of each plan; choose the best plan and give two main reasons.
Photodiode(P, J1) /Diagram 9
Strain Gage(S, J1)
Reed Switch(R, J1)
(PS, J1, J2) /
Diagram 10
(PR, J1, J2)
Symbol / Name of the component / Symbol / Name of the component
C11 / B1
C21 / B3
C32 / J
Match / Electrical Reliability / Mechanical Reliability / Price / Installation / Maintainability / Safety / Outdoor Working
P
S
R
PS
PR
Best Practices
Main reason
Reference:
Books:
Index / Author / Publish Year / Title(including sub-title) / Edition / Place of Publication / Publisher
Journal articles:
Index / Author / Publish Year / Title(including sub-title) / Journal title / Volume Number / Pages
Internet resource:
Index / Author / Publish Year / Title (including sub-title) / URLModule IV Information and Energy Control
4.1 Information Systems
4.1.1 The Strain Gage
4.1.2 Optical Sensors
4.1.3 Reed Relay
4.2 Energy Control Systems
4.2.1 SWITCHES
4.2.2 Relay
4.2.3 Contactors
4.3 Motor Control system
4.3.1 Open and Closed -loop control system
4.3.2 Permissive and Interlock Circuits
4.3.3 Three Phase Motor Reversing
An integrated assignment
1