Posted: February 12th, 2015

Welding Systems and Research Methods Assignment “Robot Welding of an Excavator Boom”

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MSc in Welding Engineering 2014-15
WPE3 Welding Systems and Research Methods
Assignment
“Robot Welding of an Excavator Boom”

I have paid to get a High degree ” excellent” in this assignment because I must raise my grades rate . please pay attention to this assignment because last time when I took my Order from you and also was an Assignment paid to you for Full Mark of excellence in the previous assignment but the university giving me the low-mark they gave me 55 from 100 mark I hope this time will not be the same as last time …
Kindly When you want me to attach the documents I will offer for you the following
1. experiments I did in our laboratory
2. work assignment and what steps should contain
3. And any other information you want need it , I will providing you with all information you need
Please Please Please There is NO extension for more than 3 days only, please I do not want Any delay
 

WPE3 Welding Systems and Research Methods Assignment “Robot Welding of an Excavator Boom” 1 Overview The assessment for this module is an assignment. The submission date is Wednesday 18 th February 2015 at 9:00 am for full-time students, and Monday 30th March 2015 at 5:00 pm for part-time students. Note that these times have been entered into Blackboard and late submissions will incur the wrath of the Exceptional Circumstances procedure! The assignment must be submitted electronically using “Turnitin”, which can be accessed via Blackboard. As a guide the assignment should not be longer than 4000 words. From 2 nd to 6 th February 2015 all students will be taking part in lectures, workshops, and laboratory exercises. The purpose of the laboratory exercise is to generate data that will be used in the assignment. You will be working together during this week, but each of you must write your own individual assignment. It is essential that your written assignment is entirely your own work, and you will receive training on avoiding plagiarism during the week. 2 Problem description The objective of the assignment is to design, evaluate and cost the application of a robot welding system to make single pass fillet welds to fabricate a small excavator boom. The details of the boom are as follows: Excavator boom: The design is shown in Figure 1. 300 to be manufactured per week 6 mm structural steel 4 mm leg length fillet welds, horizontal position Total weld length 8 m Solid wire DC MIG/MAG welding, 1.0 mm dia wire Quality requirements: 4 mm leg length (effective throat thickness needs to be 2.82 mm – see Figure 2) Undercut and concavity: less than 1.0 mm No gross porosity, cracks, lack of fusion, skips or humping (Single pores less than 2 mm acceptable) You are required to design the robot welding system for this part, and to determine the manufacturing cost per part. You will need to obtain relevant data on costs, and make suitable assumptions where necessary. You should justify your choices, and cite references for quoted information. You will need to address the following factors: 1. Design of robot system and manipulators, jigs and methods of fixturing, and a method for loading and unloading the parts.2. Determination of whether sensors are needed for robot welding, and if so, what sensors should be used. 3. Determination of welding speed to achieve required weld quality (this will be determined from the laboratory exercise – see section 4). 4. Design of the shift system and labour force required. 5. Determination of cost per part, making reasonable assumptions for costs, including labour costs, overhead costs, and consumable costs. Figure 1 Design of excavator boom. Figure 2 Effective throat thickness. 3 Structure of report Your report should be structured as follows: 1 Introduction and objectives. 2 Critical literature review: review of robotic welding systems, and sensors for robot welding. 3 Determination of welding parameters including: equipment and experimental method for welding trials, results and discussion. 4 Robot cell design and costing. A A Section A-A 1.4 m5 Conclusions. 4 Planning your experiments It is essential that you carefully plan your experiments before commencing any welding. To do this you will need to: 1. Calculate the required wirefeed speed/travel speed (WFS/TS) ratio theoretically. 2. Determine the required WFS/TS ratio experimentally, i.e. using the theoretical value as a starting point, perform experiments to determine the value required in practice. Once this has been determined, this can remain fixed for the remaining experiments (hopefully). 3. Do a systematic series of experiments to determine the effects of: · WFS · Arc voltage/trim · Torch angle In the planning session you will need to discuss what you are going to measure and how this is going to be measured. We can provide you with a gauge that enables the leg length and throat thickness to be calculated. You may want to consider how you can use these parameters to determine whether you have a concave or convex weld. In addition, how could you use these values to estimate the amount of weld metal? Each of the power supplies provides the average current and voltage which you can use to estimate the power and heat input. Finally, you may also wish to consider a qualitative assessment of your welds, e.g. 5 for excellent and 0 for poor/no weld possible. It is recommended that you look at ways of assessing experimental variability – you may want to select one of the conditions and repeat several times. In addition the throat and leg length measurements could be done at several positions along the weld. You will have limited time during the experimental session. Therefore it is suggested that you divide the work into tasks which can be performed by different group members. Consider dividing up the following activities: planning, operating the robot and measurement/assessment of welds. After performing the welding experiments you will need to select a few key samples for metallography. Please inform the technicians which ones you would like cut-up. Note that the samples will need to have a maximum diameter of 25 mm to enable mounting. At least one sample will be required per student. Note that no marks are given for the group with the highest travel speed! The only thing that this will boost is your ego. 5 Assessment The assessment sheet is shown on the next page. Please read this carefully if you want to obtain a good mark. This will help you to see what areas you will need to focus on – and also what not to focus on!SCHOOL OF APPLIED SCIENCES MSc in Welding Engineering 2014/15 WPE3 Welding Systems and Research Methods Assessment Form STUDENT’S NAME: Criteria Max mark Mark Comments Critical Literature review 20% · Find an adequate range of relevant articles which are correctly referenced using a consistent referencing style – please use Refworks if possible! · Review at an appropriate length and suitable depth, indicating the current state of the art in each area reviewed · Analytical review of the articles, leading to clear conclusions, avoiding expression of opinions without supporting references. 7 5 8 Experimental 35% · Clear description of experimental method. Marks will be given for a systematic experimental design. · Clear presentation of experimental results, in the form of graphs (and tables where necessary). Metallographic sections need to be presented clearly with a scale and referenced in the text correctly. · Analysis of experimental errors and use of error bars on graphs where possible. · Discussion and conclusions from experimental study 7 17 3 8 Robot cell design 35% · Clear description of robot cell design, indicating how it will make the four welds on the excavator boom. · Description of jigs and fixturing used to hold the plates during welding. · Analysis of part loading, and other upstream/downstream issues. · Logical analysis of part costs, using reasonable assumptions of capital and overhead costs. 23 3 3 6 Style and presentation 10% · Precision, concision and clarity. · Acceptable use of correct grammar – it must be understandable. 5 5 TOTAL MARK (%): Other comments:Hazards – Welding Operational/Events Significant Hazards Existing Controls & Limitations · Welding · Make sure that a manual is available, read and understand it before use. · Most manuals will detail the risks incurred when welding is under taken. The RA welding activities PDF file specify in great detail the risks including the instructions, requirements & regulations. ·Also the HS&E have released several documents that might be useful such as Welding fume- extraction or RPE. Also illness caused by welding fumes and gases and one on hearing loss for specifically noisy operations such as high frequency pulsing. ·EMC interferenc e ·Stray welding currents ·Sparks and spatter ·Arc radiation · Fumes ·Burns · Fire · Noise · Grounding and shielding · The work piece should be fitted with a separate earth. ·Solid connections on earth clamp · Good housekeeping to prevent fires. · Remove all flammable material in the v
icinity ·PPE to protect skin from sparks, spatter and arc radiation ·Appropriate head shield with correct filter lens. Arc radiation is a problem even when not looking directly at the arc so ensure that curtains are drawn so that other personnel and visitors are not exposed to UV light. · Obtain COSHH sheet on wire and substrate so risk of fumes can be evaluated. Consider the process, location, length of time, wire and extraction · Most of the time on most alloys LEV will be recommended. Consider whether the process is TIG, MIG or Plasma, and is it Automated or Manual? Then the hood must be placed correctly, generally the distance from the work piece to the hood should be 1- 2 times the diameter of the hood to achieve the best suction but to avoid problems with draft. ·Avoid burns by not touching the work piece straight after welding and if the work piece is left unattended then clearly mark as HOT. · Certain power sources use a high frequency pulsing which can be very loud and disturbing and if that’s the case then ear defenders must be worn.Hazards – Robot Operational/Events Significant Hazards Who is Affected? Existing Controls & Limitations ·Activity in the robot cells · Working at height Operator · Caution should be observed when stepping on and off the plinth ·Slip, trip, fall Operator · Good house keeping ·Electricity Operator · Maintenance · Operate a robot · Robotic Equipment (impact, crushing) Operator · Trained and authorised operators only. · Robot in teach mode, and starts with slow speed. ·Pendant operator must at all times know where people are in relation to the robot · Robotic welding · Flash, fume, fire. Operator · Training of the robotic welding procedure ·PPE (Safety shoes, goggles, welding mask) · UV protection curtain needs to be applied when necessary ·See the RAs of welding equipment