236 Flashcards

Question

3 types of liability

Answer 1

-strict: product unreasonably dangerous regardless of carefulness, dangerous beyond the expectation of ordinary consumer -negligence: designer/manufacturer didn't take adequate precautions in manufacturing/inspecting/testing product -warranty: product does not perform as intended, as stated by supplier or consumer guarantees act

Answer 2

"the degradation of the performance of a device or process outside of a specified value" and "non-performance or inability to perform its functions" defect: imperfection deficiency: lack of conformance to specifications fault: cause of failure malfunction: unsatisfactory performance

Answer 3

Number of failures per unit hours of operating time

Answer 4

1. early failure, initial kinks ironed out eg software 2. constant/random failures 3. wear out failures

Answer 5

probability a product will still be functioning at time t

Answer 6

1. ensure conformance to standards 2. take corrective measures if there are faults 3. take preventative measures to eliminate faults

Answer 7

common - small random changes, background noise assignable - large variations in quality, process stopped

Answer 8

product characteristics that can be measured eg size, weight

Answer 9

pros: little energy absorption by fluid, higher forces cons: oil flammable, heavy components

Answer 10

pros: fewer shock loads, lightweight, air easily available cons: lower loads, explosion possible

Answer 11

pros: low complexity/cost, compact cons: pressure and flow rate cannot be changed independently, abrasives wear teeth, sealing and losses

Answer 12

pros: high pressures for low viscosity fluids, good intake suction cons: complex, pressure and flow rate not independant

Answer 13

pros: large pressure range and viscosity range, pressure and flow rate can be controlled independently cons: complex, bulky, tight tolerances

Answer 14

-flow restrictor on piston head -increases back pressure near end of stroke -reduces flow rate slows piston -less damage risk, smooth operation

Answer 15

axial teeth engage with their opposite pros - high load capability, simple, cheap, long life cons - precise tooth alignment, cannot engage while running

Answer 16

one way transmission, ratchet mechanism

Answer 17

pros - allow running engagement, more plates = more friction, normally engaged or disengaged cons - wear, axial load from clamping force, large diameter needed for large loads

Answer 18

ceramic - most expensive, best performance, quietest metallic - good performance, loud, poor longevity organic - cheap, poor performance

Answer 19

disc offer superior stopping power and heat dissipation while drum brakes are cost-effective and durable

Answer 20

disc: loss of hydraulic pressure, pads wearing too thin, disc warping drum brakes: contamination causing loss of friction, overheating of drum

Answer 21

extrudes plastic through nozzle and builds layers ontop of each other pros: affordable, cheap material, easy to use cons: weakness in z direction, poor surface quality

Answer 22

trace of UV beam on surface if liquid photopolymer solidifies a layer at a time and then pushes build down into liquid a little bit at a time pros: best surface finish, can make clear parts cons: brittle, messy and requires supports for overhangs

Answer 23

droplets of photosensitive material put onto structure layer by layer and cured with UV light pros: best surface finish, clear parts, color parts cons: weak material, messy

Answer 24

selectively melting layers of powder with laser pros: strongest AM parts, works with metal cons: metal PBF requires inert atmosphere, required support material for heat transfer, tricky to remove support structures

Answer 25

same as powder bed fusion but uses special ink that absorbs heat and melts powder only where ink is

Answer 26

printhead selectively applies binding agent to thin layer of powder, can be used to make green parts for powder metallurgy pros: fast to produce green parts, cost effective for prototyping cons: green parts fragile, parts shrink while sintering, hard to use on large parts

Answer 27

metal powder or wire is deposited from nozzle and melted by laser pros: can repair broken parts or add features to an existing part cons: surface requires milling

Answer 28

combines directed energy deposition with multi axis cnc milling pros: can produce ready to use parts cons: difficult, high labour cost, high cost in general

Answer 29

reduce effects of heat in machining usually water based

Answer 30

reduce friction of part with tool usually oil based can also reduce temps

Answer 31

pros: high productivity, large volume of identical parts, complicated parts cons: more expensive upfront cost, alter labour force

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