Quiz
Composite Quiz
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Questions in this quiz (22)
1Which of the following best describes the wet layup process?
- AWet fiber chopped in a hand-held gun and fed into a spray of catalyzed resin directed at a mold.
- BDry fiber in the form of woven, knitted, stitched or bonded fabrics, are impregnated with resin by hand.
- CPre-impregnated fibers are laid up by hand or by machine onto a mold surface, vacuum bagged and heated to typically 120-180°C.
2Which of the following states the disadvantage of doing WLU?
- AAutoclave is necessary for composite curing.
- BHigh manufacturing cost
- CHigh viscosity resins are hard to be impregnated into fibers
3Which of the following is acceptable for a drop test?
- A27.5 inHg to 26.5 inHg in 5 mins
- B28.5 inHg to 26.5 inHg in 5 mins
- C28.5 inHg to 28.0 inHg in 5 mins
4What is the purpose of spiral tubing in the resin infusion process?
- ADirect resin from resin mix into mold
- BDistribute resin evenly across the laminate.
- CDirect the air from the mold to the vacuum bag.
- DPrevent the flow medium from bonding to the laminate.
5What are the correct layers of materials in Resin Infusion process?
- AFibers -> release film -> peel ply -> vacuum bag
- BFibers -> peel ply -> flow medium -> vacuum bag
- CFibers -> peel ply-> breather-> vacuum bag
6What is required to ensure a reliable set up for Resin Infusion? Select all that applies.
- AResin is to be degassed.
- BEnsure pressure drop of < 0.2 inHg/min
- CAvoid air from entering set-up via inlet tubing
- DAvoid having hair/fibers stuck between sealant and vacuum bag
- EConstantly press down with sufficient force around overlaps of sealant
- FFlow medium should be smaller than laminate size.
7What is the reason for choosing woven fibers over uniaxial fabrics?
- Aprovide maximum strength
- BAble to customize the fiber direction to the required angles
- CImpart strength in all directions
8What are the difference between polyester resin and epoxy resin?
- APolyester resins has good water resistance properties due to the absence of ester groups while epoxy resin has reactive sites located at the end of the molecular chains.
- BPolyester resins cure with the help of a catalyst while epoxy resins cure with the help of an amine group hardener.
- CPolyester resins have better tensile strength than epoxy resins.
9Which equation represents Hooke's Law?
- Aσ = Eε
- BE = ε/σ
- Cε = Eσ
10Given 10 plies of 250 x 250mm laminate and a resin to hardener mixing ratio of 2:1. Assuming the fiber weight of each ply is 160g/m2 and a 50% resin content by weight, how much resin and hardener is needed for wet layup respectively?
- A66g of resin and 33g of hardener
- B100g of resin and 50g of hardener
- C75g of resin and 37.5g of hardener
11Choose the most accurate stress-strain curve for a typical aligned fiber-reinforced composite exposed to uniaxial tensile stress applied in the direction of alignment. Select 1 only.
- A1
- B2
- C3
- D4
- A1
12What are the factors of consideration when choosing adhesive for bonding of laminates? Check all that apply.
- AShear strength of adhesive
- BBond time / curing time
- CAdhesion compatibility to material
- DFatigue resistance
13Adhesive selection usually depends on what materials are to be bonded, as well as other considerations, such as operating environment and process specifications. Which three types of adhesive generally used for structural bonding applications?
- ACyanoacrylates, epoxies and anaerobic adhesives
- BEpoxies, acrylics, and urethane
- CHot melt, silicones, and glue dots
14For a continuous and oriented fiber-reinforced composite, the moduli of elasticity in the longitudinal and transverse directions are 19.7 and 3.66 GPa respectively. If the volume fraction of fibers is 0.25, what is the moduli of elasticity of the fiber phase? (Use Rules of Mixtures)
- A1.02GPa
- B25.93GPa
- C70.4GPa
15At what instances is a 4-point bend test used instead of a 3-point bend test?
- AFor stress localization analysis
- BWhen test specimen is orthotropic
- CWhen shear stresses in the specimen is in consideration
16What are the forces experienced at point 1, 2 and 3 during compression testing? Choose one only for each layer. Please click on the yellow circle to key in your answer.
(Options: Normal Force, Tension Force, Frictional Force, Shear Force, Magnetic Force, Compression Force, Downwards Force, Gravitational Force)
- ACompression Force
- BShear Force
- CTension Force
17What is the preferred test specimen shape for tensile testing of composite, and why?
- AStraight, to avoid causing discontinuous fiber strand
- BStraight, to reduce the likelihood of fracture to occur at the ends of the specimen
- CDog-boned, to ensure the highest probability that the sample will fail due to maximum tensile loading
- DDog-boned, to reduce the likelihood of fracture to occur at the ends of the specimen
18What is the purpose of using tabs on tensile specimens?
- ATo introduce shear stress at the gripped tab surfaces during tensile testing
- BTo minimize the stress concentrations produced in the tab termination region by increasing cross-sectional area of tabbed region
- CTo prevent test specimen from slipping from the tensile grips
19What is the first step of risk assessment?
- AIdentify hazard
- BEstablish context
- CEvaluate risk
20Referring to the table below, what would be the risk level for an activity that is deemed moderately severe and likely to happen occasionally, and what are the prevention methods that can be done? Select 1 risk level and the relevant action(s).
- ALow Risk
- BMedium Risk
- CHigh Risk
- DNo additional risk control measures required.
- EAdequate training by a competent person is required.
- FProvide personal protective equipment (PPE) such as N95 mask and safety goggles
- GA careful evaluation of the hazards should be carried out to ensure that the risk level is reduced to as low as reasonably practicable (ALARP) within a defined time period.
- HManagement review is required before work commences.
21Which of the following controls is the least effective based on the hierarchy of controls?
- AElimination
- BAdministrative
- CPersonal Protective Equipment (PPE)
22Please enter your name: [blank_start]_________________[blank_end].
Please screenshot the test results once you have submitted the quiz, and email Xander the score. You may review the questions after completion. Explanations are provided to the best of my abilities. Thank you for completing the quiz!- A_________________
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- Description
- ello new interns if you see this you must be editting it or bored, quiz made by Serena. Rian wrote dis :D
- Author
- CTOACW Intern
- Language
- English
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