📚 Year 9 CAIE Engineering: Key Terminology Quick Revision Guide | Year 9 CAIE 工程：词汇术语速记指南
Mastering engineering terminology is the first step towards thinking like an engineer. This guide breaks down the essential vocabulary from the Year 9 CAIE Engineering syllabus into clear, concise definitions with examples, helping you commit key terms to memory quickly and effectively.
掌握工程术语是迈向工程师思维的第一步。本指南将 Year 9 CAIE 工程大纲中的核心词汇拆解成清晰简洁的定义与示例，帮助你快速、高效地记住关键术语。
1. Material Properties | 材料特性
Hardness – A measure of a material's ability to resist scratching, indentation or wear. Hard materials like tool steel are used for cutting edges.
硬度 – 衡量材料抵抗刮擦、压入或磨损能力的指标。工具钢等硬材料用于制作切削刃。
Toughness – The capacity of a material to absorb energy and deform plastically without fracturing. Car chassis rely on tough materials such as mild steel.
韧性 – 材料吸收能量并发生塑性变形而不断裂的能力。汽车底盘依赖低碳钢等韧性材料。
Ductility – The ability to be stretched into a wire without snapping. Copper exhibits high ductility, making it ideal for electrical cables.
延展性 – 材料被拉成细丝而不断裂的能力。铜表现出很高的延展性，非常适合制造电缆。
Elasticity – The property that allows a material to return to its original shape after the load is removed. A spring demonstrates elasticity up to its elastic limit.
弹性 – 材料在载荷移除后恢复原状的特性。弹簧在其弹性极限内可展现出弹性。
Density – Mass per unit volume of a material. Engineers select low-density materials like aluminium for aircraft to save weight.
密度 – 材料单位体积的质量。工程师为减轻重量而选择铝等低密度材料制造飞机。
2. Forces and Stress | 力与应力
Force – A push or pull acting on an object, measured in newtons (N). When you sit on a chair, your weight exerts a downward force.
力 – 作用于物体上的推或拉，单位是牛顿 (N)。当你坐在椅子上时，你的体重会施加向下的力。
Stress – The internal force per unit area within a material. Tensile stress is calculated by dividing the pulling force by the cross-sectional area. The formula is often written as:
应力 – 材料内部单位面积所受的内力。拉应力通过拉力除以横截面积计算。公式通常写作：
σ = F / A
Strain – The deformation per unit length caused by stress. It has no units because it is a ratio of extension to original length:
应变 – 应力引起的单位长度变形量。因为它是伸长量与原始长度的比值，所以没有单位：
ε = ΔL / L₀
Hooke's Law – elastic limit is not exceeded. It is expressed as F = kx, where k is the spring constant.
胡克定律 – 指出弹簧的伸长量与所受外力成正比，前提是不超过弹性极限。表达式为 F = kx，其中 k 为弹簧常数。
Shear Force – A force that causes parts of a material to slide past one another. Scissors apply a shear force to cut paper.
剪切力 – 使材料各部分相互滑移的力。剪刀对纸张施加剪切力进行裁剪。
3. Mechanisms and Motion | 机构与运动
Lever – A rigid bar that pivots around a fulcrum to amplify an input force. A crowbar is a first-class lever with the fulcrum between effort and load.
杠杆 – 一根绕支点转动的刚性杆，用于放大输入力。撬棍属于第一类杠杆，支点在施力点与负载之间。
Gear – A toothed wheel that meshes with another to transmit torque and change rotational speed. A small gear driving a larger gear increases torque and reduces speed.
齿轮 – 一种带齿的轮子，与另一齿轮啮合以传递扭矩并改变转速。小齿轮驱动大齿轮可增大扭矩并降低转速。
Pulley – A wheel with a grooved rim for holding a rope or belt, used to change the direction of a force or gain mechanical advantage. A block and tackle system uses multiple pulleys to lift heavy loads.
滑轮 – 带有凹槽边缘的轮子，用于固定绳索或皮带，可改变力的方向或获得机械利益。滑轮组系统使用多个滑轮提升重物。
Cam and Follower – A shaped rotating piece (cam) that pushes a sliding rod (follower) to create reciprocating motion. This mechanism opens engine valves.
凸轮与从动件 – 一个成形旋转件（凸轮）推动滑动杆（从动件）产生往复运动。发动机气门通过该机构开启。
Crank and Slider – Converts rotary motion into linear motion. A crankshaft and piston in a car engine form a crank and slider mechanism.
曲柄滑块机构 – 将旋转运动转化为直线运动。汽车发动机中的曲轴和活塞即构成曲柄滑块机构。
4. Electronics Fundamentals | 电子基础
Voltage (V) – The electrical potential difference that pushes current through a circuit, measured in volts (V). A battery provides the voltage.
电压 (V) – 推动电流通过电路的电势差，单位为伏特 (V)。电池提供电压。
Current (I) – The flow of electric charge, measured in amperes (A). Current flows from the positive terminal to the negative terminal in conventional notation.
电流 (I) – 电荷的流动，单位为安培 (A)。在惯用表示法中，电流从正极流向负极。
Resistance (R) – The opposition to current flow, measured in ohms (Ω). Long thin wires have higher resistance than short thick wires.
电阻 (R) – 对电流流动的阻碍，单位为欧姆 (Ω)。细长导线的电阻比短粗导线大。
Ohm's Law – The relationship between voltage, current and resistance: V = I × R.
欧姆定律 – 电压、电流与电阻之间的关系：V = I × R。
Series and Parallel Circuits – In a series circuit, current is the same everywhere and total resistance is R₁ + R₂ + … ltage is the same across each branch and total resistance is found from 1/R = 1/R₁ + 1/R₂.
串联与并联电路 – 串联电路中各处电流相等，总电阻为 R₁ + R₂ + … 。并联电路中各支路电压相同，总电阻由 1/R = 1/R₁ + 1/R₂ 求得。
Power (P) – The rate at which electrical energy is converted, measured in watts (W). P = I × V.
功率 (P) – 电能转化的速率，单位为瓦特 (W)。P = I × V。
5. Manufacturing Processes | 制造工艺
Casting – Pouring molten material into a mould cavity and letting it solidify. Sand casting is widely used for making engine blocks.
铸造 – 将熔融材料倒入模具型腔并使其凝固。砂型铸造广泛用于制造发动机缸体。
Forging – Shaping metal using compressive forces, often while hot. Wrenches and crankshafts are typically forged for superior strength.
锻造 – 利用压缩力对金属进行成形，通常加热后进行。扳手和曲轴常通过锻造以获得更高强度。
Turning – A machining process where a cutting tool removes material from a rotating workpiece. Cylindrical parts like shafts are produced on a lathe.
车削 – 利用切削刀具从旋转的工件上切除材料的加工方法。轴类圆柱形零件在车床上生产。
Milling – A process using a rotating multi-tooth cutter to remove material from a stationary workpiece. Slots, pockets and profiles are created on a milling machine.
铣削 – 使用旋转多齿刀具从固定工件上切除材料的工艺。槽、型腔和外形轮廓均在铣床上加工。
Additive Manufacturing (3D Printing) – Building a part layer by layer directly from a digital model, opposite to cutting away material. It is commonly used for rapid prototyping.
增材制造（3D 打印） – 直接根据数字模型逐层堆积零件，与切削材料相反。常用于快速原型制作。
6. Engineering Drawing Conventions | 工程制图规范
Orthographic Projection – A way of representing a 3D object in two dimensions using multiple views (front, top, side). Every exam sketch should align views correctly.
正交投影 – 使用多个视图（前、俯、侧视图）在二维平面上表现三维物体的方法。考试草图中的各视图必须正确对齐。
Isometric Drawing – A pictorial drawing where the three axes are equally foreshortened at 30° to the horizontal. It gives a realistic 3D appearance.
等轴测图 – 三根轴与水平线均成 30° 角的立体图，可呈现逼真的三维效果。
Dimensioning – The precise indication of measurements on a drawing, including extension lines, dimension lines and numerical values in millimetres.
尺寸标注 – 在图纸上精确标出尺寸，包括尺寸界线、尺寸线以及以毫米为单位的数值。
Tolerance – sion. A shaft dimensioned as 20 ± 0.1 mm must be manufactured between 19.9 mm and 20.1 mm.
公差 – 相对于指定尺寸的允许变动范围。标注为 20 ± 0.1 mm 的轴必须制造在 19.9 mm 至 20.1 mm 之间。
CAD (Computer-Aided Design) – Software used to create, modify and analyse designs. AutoCAD and SolidWorks are common CAD packages.
CAD（计算机辅助设计） – 用于创建、修改和分析设计的软件。AutoCAD 和 SolidWorks 是常见的 CAD 软件。
7. Structural Elements | 结构构件
Beam – A horizontal structural member that resists bending under load. Bridges and floor joists use beams to span openings.
梁 – 承受载荷下弯曲的水平结构构件。桥梁和楼板搁栅使用梁来跨越开口。
Column – A vertical member designed to carry compressive loads. Concrete pillars in a building act as columns.
柱 – 设计用于承受压缩载荷的竖向构件。建筑中的混凝土支柱即为柱。
Truss – A framework of triangles that provides high strength with less material. Roof trusses and crane jibs rely on truss structures.
桁架 – 由三角形构成的框架，能以较少材料提供高强度。屋架和起重机吊臂均依赖桁架结构。
Cantilever – A beam anchored at only one end. A diving board is a simple cantilever.
悬臂 – 仅在一端固定的梁。跳水板就是一个简单的悬臂结构。
Triangulation – The use of triangular shapes in structures to prevent distortion. Why do you see so many triangles in bridges? Because a triangle cannot change shape without changing side lengths.
三角形加固 – 在结构中使用三角形来防止变形。为什么桥梁中有那么多三角形？因为三角形在不改变边长的情况下形状不会改变。
8. Tools, Machines and Safety | 工具、机器与安全
Hacksaw – A fine-toothed saw used for cutting metal and plastic. The blade is held under tension in a frame and can be replaced when worn.
钢锯 – 用于切割金属和塑料的细齿锯。锯条在锯架上绷紧，磨损后可更换。
File – A hand tool with a hardened surface of small teeth for removing small amounts of material and smoothing edges. Cross-filing and draw-filing are common techniques.
锉刀 – 一种表面布满硬化细齿的手工工具，用于去除少量材料并修光边缘。交叉锉和推锉是常用技法。
Drilling Machine – A power tool that rotates a drill bit to cut holes in a workpiece. The spindle speed can be changed to suit different materials.
钻床 – 一种电动工具，旋转钻头在工件上钻孔。主轴转速可调，以适应不同材料。
Centre Lathe – A machine tool that rotates the workpiece while a cutting tool is fed against it. It performs turning, facing, and drilling operations.
普通车床 – 使工件旋转同时推进切削刀具的机床。可进行车外圆、端面加工和钻孔等操作。
Personal Protective Equipment (PPE) – Equipment worn to minimise exposure to hazards. In a workshop, safety glasses, steel-toe boots and aprons are mandatory.
个人防护装备 (PPE) – 佩戴以最大限度降低危害暴露的装备。在车间中，护目镜、安全鞋和围裙是强制佩戴的。
9. Energy, Work and Power | 能量、功与功率
Work Done – W) = force (F) × distance moved in the direction of the force (d). Measured in joules (J).
功 – 力使物体移动时传递的能量。功 (W) = 力 (F) × 沿力方向移动的距离 (d)，单位为焦耳 (J)。
Kinetic Energy (KE) – The energy an object possesses due to its motion. The formula is:
动能 (KE) – 物体因运动而具有的能量，公式为：
KE = ½ m v²
Gravitational Potential Energy (GPE) – n object because of its height above the ground. GPE = m g h, where g is 10 m/s² on Earth.
重力势能 (GPE) – 物体因离地高度而储存的能量。GPE = m g h，在地球上 g 取 10 m/s²。
Power – aken. Measured in watts (W). An engine with higher power can do the same work in less time.
功率 – 做功或传递能量的速率。功率 (P) = 做功量 / 时间，单位为瓦特 (W)。功率越大的发动机能在更短时间内完成同等功。
Efficiency – energy, often expressed as a percentage. Efficiency = (useful output / total input) × 100%. No machine is 100% efficient due to friction.
效率 – 有用输出能量与总输入能量的比值，通常以百分数表示。效率 = (有用输出 / 总输入) × 100%。由于存在摩擦，没有机器能达到 100% 效率。
10. The Design Process | 设计流程
Design Brief – A clear statement outlining the problem, the need, and the constraints. It provides direction at the start of a project.
设计任务书 – 对问题、需求和约束条件的清晰陈述，为项目启动提供方向。
Specification – A detailed list of requirements a final design must meet, including performance, materials, size, cost and safety.
设计规格 – 最终设计必须满足的详细要求清单，涵盖性能、材料、尺寸、成本和安全性等方面。
Iterative Design – A cyclic process of prototyping, testing, evaluating and refining. Engineers improve the design with each cycle based on test feedback.
迭代设计 – 原型制作、测试、评估与改进的循环过程。工程师根据测试反馈在每一轮迭代中完善设计。
Modelling – Creating a simplified representation of a product to test ideas. It can be a physical model made of cardboard or a virtual CAD model.
建模 – 创建产品的简化表示以测试想法。可以是纸板制作的实体模型，也可以是虚拟的 CAD 模型。
Evaluation – Critically comparing the final product against the specification to judge its success. Good evaluation identifies strengths, weaknesses and further improvements.
评估 – 将最终产品与设计规格进行严格对比，判断其成功程度。优质的评估会识别出优点、不足及进一步的改进方向。
11. Measurement and Precision | 测量与精度
Vernier Caliper – A precision instrument that measures internal, external and depth dimensions, commonly reading to 0.1 mm or 0.02 mm. It uses a vernier scale for improved accuracy.
游标卡尺 – 一种可测量内径、外径和深度的精密量具，常见读数精度为 0.1 mm 或 0.02 mm，借助游标尺提高精确度。
Micrometer – A gauge measuring small distances with a typical precision of 0.01 mm. The thimble and ratchet mechanism ensure consistent measuring force.
千分尺 – 一种测量微小距离的量具，典型精度为 0.01 mm。微分筒和棘轮机构可保证恒定的测量力。
Zero Error – An incorrect reading when the measuring instrument should read zero. Before taking a measurement, you must check and correct for zero error.
零误差 – 测量仪器本应归零却显示错误读数的情况。测量前必须检查并修正零误差。
Accuracy vs. Precision – Accuracy is closeness to the true value; precision is the consistency of repeated measurements. A dartboard analogy: a tight group off-centre is precise but not accurate.
准确度与精密度 – 准确度指与真值的接近程度；精密度指多次测量结果的一致性。用飞镖靶来比喻：一簇紧密但偏离靶心的结果精密度高但准确度低。
12. Environmental Considerations | 环境考量
Sustainable Design – Creating products that minimise negative environmental impact through material selection, energy use and longevity. Bamboo furniture is an example of renewable material use.
可持续设计 – 通过材料选择、能源使用和长使用寿命来最大限度减少负面环境影响的产品设计。竹制家具就是使用可再生材料的例子。
Life Cycle Assessment (LCA) – A method for evaluating the environmental impact of a product from raw material extraction to disposal. LCA considers carbon footprint, water usage and pollution.
生命周期评估 (LCA) – 从原材料获取到废弃处置，评估产品整个生命周期环境影响的方法。LCA 考虑碳足迹、水资源使用和污染。
Recyclability – The ability of a material to be reprocessed and used again. Aluminium cans are widely recycled, saving up to 95% of the energy needed for primary production.
可回收性 – 材料被再加工并重新利用的能力
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