1. Unit 4: Engineering Design Discussing Dimensions and Precision Dr. Hatem Elaydi Engineering Technical English Islamic University of Gaza March 12, 2016

2. Outline Working with Drawings Discussing Dimensions and Precision Describing Design Phases and Procedures Resolving Design Problems Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 2

3. II. Discussing Dimensions and Precision 6a. Discuss what is meant by precision and accuracy Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 3 Answers The words mean how exact something is, for example how closely the sizes of manufactured items match their designed size. Answers The words mean how exact something is, for example how closely the sizes of manufactured items match their designed size.

4. II. Discussing Dimensions and Precision You are engineers on a project to design the metal handrail that will run around the perimeter of the top, outdoor deck of a large cruise ship. In groups, discuss what drawings you will need to produce for manufacturing and installation with regard to the following issues: The types of view that will be required and what each one will show. The approximate scale of different drawings and views. What written information you will need to provide in the specification. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 4

5. 5 Superflat floor: FAO What is a superflat floor? Compacting and finishing the surface of wet concrete is an inherently imprecise process. For an ordinary concrete slab to be laid within tolerance, engineers can only realistically expect the surface to be finished to plus or minus 5 mm. By contrast, superflat concrete floor are finished to meet extremely close tolerances, being accurate to within 1 mm across their upper surface. Where are superflat floors used? Floor surfaces with extremely tight tolerances are frequently specified in warehouses where Automated Guided Vehicle s operate. Uneven floors are especially problematic in high bay warehouses, which use automated forklifts with a vertical reach of 30 meters o more. At such a height, slight variations in floor level are amplified in the form of vertical tilt, causing inaccurate maneuvering at a high level. If these variations outside tolerance they can lead to collisions with racking elements, or causing items to be dropped from pallets.

6. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 13056 6b. Read the technical advice web page and answer the following questions. 1. How is a superflat floor different from an ordinary concrete floor? 2. What accuracy can be achieved with ordinary slabs, and with superflat slabs? 3. What problem is described in high bay warehouses Answers 1 A super flat floor has a much flatter surface. It’s finished more precisely than an ordinary concrete floor. 2 Ordinary slabs can be flat to ±5mm. Super flat slabs can be flat to within 1mm. 3 Slight variations in floor level can cause forklifts to tilt, causing the forks to hit racks or drop items.

7. II. Discussing Dimensions and Precision 6c. Discuss what is meant by tolerance in the context of dimensions and precision. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 7 Tolerance is the acceptable difference between ideal designed size and actual size. In machining and assembly processes, it is impossible to achieve entirely precise sizes. A degree of tolerance is always required. 6d. Complete the following expressions from the web page which are used to describe tolerances. I ---------- tolerance (inside the limits of a given tolerance) 2 -------- or ------5mm (+/-5mm) 3 --------- tolerance (close tolerance) 4 - ------- tolerance (not inside the limits of tolerance) Answers 1 within 2 plus;/minus 3 tight 4 outside Answers 1 within 2 plus;/minus 3 tight 4 outside

8. 6e. Complete the following sentences using the expressions in Exercise 6d. 1 The frame's too big for the opening. The opening's the right size, so the frame must be----------- 2 The total tolerance is 1 mm. The permissible variation either side of the ideal is ------ 3 The engineer specified + / - 5mm for the slab finish, and we got it to +1/-2 mm. So it's well ------------ 4 You can't finish concrete to + / - 0. 1 mm. There's no way you can work to such a------ Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 8 Answers 1 outside tolerance 3 within tolerance 2 ± 0.5 mm 4 tight tolerance Answers 1 outside tolerance 3 within tolerance 2 ± 0.5 mm 4 tight tolerance

9. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 9 Mei, a structural engineer, is talking to Lewis, a project manager, about the floor specification for a manufacturing plant that is currently at design stage. Listen to the conversation and answer the following questions.

10. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 130510 1.What has the client requested with regard to the floor slab? 2.What are free movement floors and defined movement floors? 3.What issue does the engineer discuss regarding quality? 4.What option is discussed involving grinding? 5.What can be done to the reinforcement to permit grinding?

11. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 130511

12. II. Discussing Dimensions and Precision Do 7a, and 7b 7c. Mei has done a revised drawing for the floor slab. Read the extract from her email about the new design and complete the message using the correct form of the words in Exercise 7b. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 12 Answers 2 width 3 length 4 depth 5 thickness 6 height Answers 2 width 3 length 4 depth 5 thickness 6 height

13. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 13 Types of drawing required: a plan showing the perimeter of the handrail (possible scale 1:100); an elevation of a short length of the handrail (possible scale 1:10); a section of the handrail (possible scale 1:10); details showing key connections, such as those between handrail posts and deck, and top rail and posts (possible scale-actual size). Specification type of steel, types of welded joint, types of bolt, type and color of paint/coating other materials such as Plastic surround to top rail

14. HW Do Q8 Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 14

15. III. Describing Design Phases and Procedures Language note You will find the following vocabulary useful in this section. design brief, preliminary drawing, working drawing, (rough) sketch amend, amendment, approve, approval, circulate, comment on, issue, resolve, revise, revision, specify, supersede Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 15

16. III. Describing Design Phases and Procedures 9. Discuss what is meant by a design process. In engineering, what are the stages in the development of designs? Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 16 Answers A design process is the development of a design. A typical design starts with a design brief, which states the design objectives. Initial ideas are then put together as rough sketches. These are then developed into preliminary drawings, which are more detailed and are often drawn to scale. The preliminary drawings are then developed, incorporating comments from different members of the design team, consultants and the client. Once the design has been sufficiently developed, working drawings are produced. These are then used for manufacturing/assembly/construction. Frequently, working drawings are revised (changed) during this latter phase, in order to resolve technical problems encountered during manufacturing/assembly/construction.

17. III. Describing Design Phases and Procedures The following extracts from emails relate to a project to build an indoor ski complex in Australia, using artificial snow. The messages were circulated by an engineer to members of the design team, and to a specialist contractor. Read the emails and answer the following questions. Note that the emails are not in the correct order. 1 What are all the emails about? 2 What different types of document are mentioned? Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 17

18. III. Describing Design Phases and Procedures Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 18

19. III. Describing Design Phases and Procedures Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 19 Answers 1 design information (at different stages of the design process) 2 sketches, design brief, revised/amended drawing, superseded drawing, preliminary drawing, working drawing, summary/notes Answers 1 design information (at different stages of the design process) 2 sketches, design brief, revised/amended drawing, superseded drawing, preliminary drawing, working drawing, summary/notes 10b. Put the emails in the correct sequence 1……… 2……… 3……… 4……… 5……… 10b. Put the emails in the correct sequence 1……… 2……… 3……… 4……… 5……… Answers 1 b 2 d 3 c 4 a 5 e Answers 1 b 2 d 3 c 4 a 5 e

20. III. Describing Design Phases and Procedures 10c. Complete the following definitions using the types of drawing in the box Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 20 Design brief preliminary drawing sketch working drawing Answers 1 sketch 2 design brief 3 working drawing 4 preliminary drawing

21. IV. Resolving Design Problems Language note You will find the following vocabulary useful in this section. advise, clarify, confirm, disregard, indicate, propose, request, state, work to alternative, as per, clash, conflict, contradict, discrepancy Language note You will find the following vocabulary useful in this section. advise, clarify, confirm, disregard, indicate, propose, request, state, work to alternative, as per, clash, conflict, contradict, discrepancy Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 21

22. IV. Resolving Design Problems 13c. Complete the following pairs of sentences using the verbs in the box. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 22 Advise clarify clash propose request Answers 1 clash 2 request 3 propose 4 advise 5 clarify Answers 1 clash 2 request 3 propose 4 advise 5 clarify

23. IV. Resolving Design Problems 14b. Chen, a technician, is explaining the problem in Exercise 14ato Ron, an engineer. Complete the conversation using the words in the box. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 1305 23 alternative as per clarify clash confirm contradicts discrepancy propose Answers 2 clarify 3 contradicts 4 clash 5 propose 6 alternative 7 as per 8 confirm Answers 2 clarify 3 contradicts 4 clash 5 propose 6 alternative 7 as per 8 confirm

24. Dr. Hatem Elaydi, IUG, Spring 2016, ENGG 130524