WACE MDT ATAR flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Design brief
- A document stating the problem to solve, the target user, constraints, and success criteria. It guides all later design decisions and provides the basis for evaluation.
- Constraint versus criterion
- A constraint is a fixed limit a solution must satisfy, such as maximum cost. A criterion is a measurable goal used to compare solutions, such as minimum mass.
- Functional decomposition
- Breaking a product into sub-functions such as store energy or transmit force. Each sub-function is solved separately, then combined into a complete design.
- Anthropometric percentile use
- Design reach limits to the 5th percentile so most users can reach, and clearance to the 95th percentile so most users fit. Using the mean excludes many users.
- DFMA purpose
- Design for manufacture and assembly reduces part count and simplifies handling. Fewer, simpler parts lower assembly time, cost, and opportunities for defects.
- Patent versus design registration
- A patent protects a new functional invention for a limited term. A design registration protects a product's visual appearance, such as shape or pattern.
- Life cycle assessment
- Evaluation of environmental impacts across raw material extraction, manufacture, distribution, use, and end-of-life. Impacts are reported per functional unit for fair comparison.
- Iterative prototyping
- Building and testing successive models to gather user feedback early. Each cycle refines requirements and reduces the risk of costly changes late in development.
- Stress formula
- Stress equals force divided by cross-sectional area, measured in newtons per square millimetre or megapascals. It describes internal load intensity, not total force.
- Strain formula
- Strain equals change in length divided by original length and is dimensionless. It quantifies deformation relative to the material's starting dimensions.
- Young's modulus
- The ratio of stress to strain within the linear elastic region. A higher modulus means a stiffer material that deflects less under the same load.
- Yield strength
- The stress at which a material stops behaving elastically and begins permanent plastic deformation. Design loads are usually kept below this value with a safety factor.
- Toughness versus ductility
- Toughness is the energy a material absorbs before fracture. Ductility is the plastic strain before failure. A material can be ductile but not necessarily tough.
- Carbon content in steel
- Increasing carbon raises hardness and tensile strength but reduces ductility and weldability. This trade-off governs selection of low, medium, and high carbon steels.
- Thermoplastic versus thermoset
- Thermoplastics soften when reheated and can be remoulded and recycled. Thermosets cross-link permanently, cannot be remelted, and resist heat better.
- Composite anisotropy
- Properties differ by direction because reinforcement carries load along its alignment. Design must orient fibres along principal stress paths, and recycling is difficult.
- Specific strength
- Strength divided by density. It indicates performance per unit mass and explains why lightweight alloys and composites suit aircraft and transport applications.
- Cathodic protection
- A more reactive metal, or an applied current, is used to protect a metal from corrosion. The sacrificial metal corrodes instead of the protected structure.
- Sand casting
- Molten metal is poured into a sand mould and allowed to solidify. It suits complex ferrous parts at low to medium volume with relatively rough surface finish.
- Die casting
- Molten non-ferrous metal is forced into a reusable steel die under pressure. It gives fine detail and high volume but needs high tooling investment.
- Forging advantage
- Shaping metal by compressive force aligns grain flow with the part shape. This improves strength and fatigue resistance compared with casting or machining from solid.
- Turning versus milling
- Turning rotates the workpiece against a single-point tool to make cylindrical forms. Milling rotates a multi-tooth cutter against a stationary workpiece to make flat or profiled surfaces.
- Brazing versus welding
- Welding fuses the parent materials. Brazing joins them with a filler that melts above 450 degrees Celsius but below the parent melting point, avoiding parent fusion.
- Draft angle
- A slight taper, commonly one to two degrees, on moulded part walls. It allows the part to be ejected from the mould without scuffing or distortion.
- Additive manufacturing
- Parts are built layer by layer from a digital model. The process suits low-volume complex geometry but is slower and often weaker across layer boundaries.
- Takt time
- Available production time divided by customer demand. It sets the pace at which one unit must be completed to meet demand without excess inventory.
- Tolerance and go/no-go gauge
- Tolerance is the permitted deviation from a nominal dimension. A go/no-go gauge quickly checks whether a feature lies within the upper and lower limits.
- Critical path
- The longest-duration sequence of dependent activities through a project network. It has zero float, so any delay on it delays the whole project.
- Float calculation
- Float equals latest start minus earliest start for an activity. Positive float means the activity can be delayed without moving the project completion date.
- Work breakdown structure
- A hierarchical decomposition of project deliverables into work packages. Each package can be estimated, scheduled, assigned, and controlled independently.
- Break-even quantity
- Fixed costs divided by the difference between unit price and variable cost per unit. It is the output at which total revenue equals total cost.
- Risk treatment options
- Risks are treated by avoidance, reduction, transfer such as insurance, or acceptance. Treatment follows assessment of likelihood and consequence.