📚 Key Terminology Quick Reference for Year 12 OCR Engineering | OCR 12年级工程词汇术语速记指南
This guide is designed to help Year 12 OCR Engineering students master the essential terminology required for the course. Each section pairs concise English definitions with clear Chinese translations, covering materials, mechanics, electronics, manufacturing, safety, drawing and design processes. Understanding these key terms will support both written examinations and practical projects.
本指南旨在帮助12年级OCR工程学生掌握课程必备的核心术语。每一节都配有简洁的英文定义和清晰的中文翻译，涵盖材料、力学、电子、制造、安全、制图与设计流程。理解这些关键术语将有助于笔试和动手项目。
1. Materials and Properties | 材料与性能
Engineers must understand a wide range of material properties to choose the right material for each component. Mechanical properties describe how a material responds to forces, while physical and chemical properties influence corrosion resistance, weight and thermal behaviour.
工程师必须理解广泛的材料性能，以便为每个部件选择合适的材料。力学性能描述材料如何对力做出反应，而物理和化学性能则影响耐腐蚀性、重量和热行为。
Tensile strength is the greatest stress a material can withstand while being stretched before it fractures. It is a key indicator of how much pulling force a component can handle.
抗拉强度是材料在拉伸至断裂前所能承受的最大应力。它是衡量一个部件能承受多大拉力的关键指标。
Yield strength marks the stress at which a material starts to deform plastically. Beyond this point, the material will not return to its original shape when the load is removed.
屈服强度表示材料开始发生塑性变形的应力。超过该点后，卸去载荷材料将无法恢复原状。
Young's modulus (E) quantifies stiffness by measuring the ratio of stress to strain in the elastic region. A high modulus means the material resists deformation.
杨氏模量 (E) 通过测量弹性区内应力与应变的比值来量化刚度。模量高意味着材料抗变形能力强。
E = σ / ε
Ductility describes how much a material can be stretched or drawn into a wire without breaking. Copper exhibits excellent ductility.
延展性描述材料能被拉伸或拉成丝而不断裂的程度。铜具有优良的延展性。
Toughness is the ability to absorb energy and plastically deform without fracturing. Tough materials can withstand impact loads.
韧性是材料吸收能量并发生塑性变形而不断裂的能力。韧性材料能承受冲击载荷。
Hardness measures resistance to indentation, scratching or wear. Common scales include Brinell, Vickers and Rockwell.
硬度衡量材料抵抗压痕、划伤或磨损的能力。常见标尺有布氏、维氏和洛氏硬度。
2. Stress, Strain and Mechanical Testing | 应力、应变与力学测试
When a force acts on a component, internal stress and deformation occur. Standardised tests provide reliable data for comparing materials and ensuring safety factors.
当力作用在部件上时，会产生内应力和变形。标准化测试为比较材料和确保安全系数提供了可靠数据。
Stress (σ) is the internal force per unit area, measured in pascals (Pa) or N/m². Direct stress can be tensile or compressive.
应力 (σ) 是单位面积上的内力，单位为帕斯卡 (Pa) 或 N/m²。正应力可以是拉伸或压缩应力。
σ = F / A
Strain (ε) is the dimensionless ratio of change in length to original length. It represents how much a material stretches or compresses.
应变 (ε) 是长度变化量与原长之比，无量纲。它表示材料被拉伸或压缩了多少。
ε = ΔL / L₀
Ultimate tensile strength (UTS) is the peak stress on a stress-strain curve before necking and fracture occur.
极限抗拉强度 (UTS) 是应力-应变曲线上出现颈缩和断裂之前的峰值应力。
Proof stress is used for materials without a clear yield point, such as aluminium. It defines the stress that creates a 0.2% permanent strain.
规定非比例伸长应力 (或称屈服强度) 用于没有明显屈服点的材料，如铝。它定义为产生0.2%永久应变的应力。
The Brinell test uses a hardened steel or carbide ball indenter; the resulting impression diameter indicates hardness. Vickers uses a diamond pyramid for a wider range of materials.
布氏硬度测试 使用硬化钢或硬质合金球压头；所得压痕直径可反映硬度。维氏硬度采用金刚石正四棱锥压头，适用材料范围更广。
Fatigue limit is the maximum stress amplitude a material can endure for a very high number of cycles without failing. It is critical for rotating or vibrating parts.
疲劳极限 是材料在极高循环次数下不失效所能承受的最大应力幅值。对于旋转或振动部件极为关键。
3. Engineering Materials | 工程材料
Selecting from ferrous, non-ferrous, polymers, ceramics and composites determines weight, cost, environmental resistance and manufacturing routes.
在黑色金属、有色金属、聚合物、陶瓷和复合材料之间进行选择，决定了重量、成本、耐环境性和制造路线。
Ferrous metals contain iron and usually have strong magnetic properties. Carbon steel, stainless steel and cast iron are common; they may require coatings to prevent rust.
黑色金属 含铁，通常具有较强的磁性。碳钢、不锈钢和铸铁较为常见；可能需要涂层以防生锈。
Non-ferrous alloys such as aluminium alloys and copper alloys offer high corrosion resistance, low density or excellent conductivity. They do not contain significant iron.
有色金属合金 例如铝合金和铜合金，提供高耐腐蚀性、低密度或优良的导电性。它们不含大量铁。
Thermoplastics (e.g. ABS, nylon) soften when heated and can be remoulded many times. Thermosets (e.g. epoxy, phenolic) set permanently upon curing and cannot be reshaped.
热塑性塑料 (如ABS、尼龙) 受热软化，可多次重塑。热固性塑料 (如环氧树脂、酚醛树脂) 固化后永久定形，不能重新塑形。
Ceramics are hard, brittle, heat-resistant and electrically insulating. Alumina and silicon carbide are used in cutting tools and engine components.
陶瓷 坚硬、脆性、耐热且电绝缘。氧化铝和碳化硅用于切削刀具和发动机部件。
Composites combine two or more distinct materials to achieve better properties. CFRP (carbon fibre reinforced polymer) offers high strength-to-weight ratio; GRP (glass reinforced polymer) is economical.
复合材料 将两种或多种不同材料结合起来，以获得更佳性能。碳纤维增强聚合物 (CFRP) 提供高强度重量比；玻璃纤维增强聚合物 (GRP) 经济实用。
Smart materials respond to stimuli: shape memory alloys (e.g. Nitinol) return to a preset shape when heated; piezoelectric materials generate voltage under mechanical stress.
智能材料 能对外界刺激作出响应：形状记忆合金 (如镍钛诺) 加热时恢复预定形状；压电材料在机械应力下产生电压。
4. Forces, Moments and Equilibrium | 力、力矩与平衡
A solid understanding of statics is needed to analyse structures, levers and support reactions. Engineers use free body diagrams and apply Newton's laws.
要分析结构、杠杆和支反力，需要扎实的静力学知识。工程师使用受力图并应用牛顿定律。
Force (F) is a push or pull that can cause an object to accelerate, measured in newtons (N). Weight is the gravitational force on a mass.
力 (F) 是能使物体加速的推或拉，单位为牛顿 (N)。重量是作用在质量上的重力。
F = m × a
Moment (M) is the turning effect of a force about a pivot, calculated as force multiplied by the perpendicular distance from the pivot.
力矩 (M) 是力绕支点的转动效应，等于力乘以从支点到力作用线的垂直距离。
M = F × d
Principle of moments states that for a body in rotational equilibrium, the sum of clockwise moments equals the sum of anticlockwise moments about any pivot.
力矩原理 指出对于处于转动平衡的物体，绕任一枢轴的所有顺时针力矩之和等于逆时针力矩之和。
∑ M꜀꜀ = ∑ Mₐ꜀꜀
Equilibrium occurs when the resultant force and resultant moment on a body are both zero. A free body diagram isolates the object to show all external forces.
平衡 发生在合力与合力矩均为零时。隔离体受力图将物体独立出来以显示所有外力。
Direct stress and shear stress are important in joints. Direct stress acts normal to a surface, while shear stress acts parallel, as in bolted connections.
正应力与剪应力 在连接中很重要。正应力垂直作用于表面，而剪应力平行作用，例如螺栓连接中。
Factor of safety is the ratio of ultimate strength to allowable design stress. It accounts for uncertainties in loading, material and manufacturing.
安全系数 是极限强度与许用设计应力之比。它用于应对载荷、材料和制造中的不确定性。
5. Electrical and Electronic Principles | 电气与电子原理
Modern engineering integrates electronic control. Mastering Ohm's law, power relationships and circuit laws is essential for sensor and actuator design.
现代工程集成了电子控制。掌握欧姆定律、功率关系和电路定律对于传感器和执行器设计至关重要。
Current (I) is the rate of flow of electric charge, measured in amperes (A). Voltage (V) is the electrical potential difference that drives current, measured in volts (V). Resistance (R) opposes current, measured in ohms (Ω).
电流 (I) 是电荷流动的速率，单位为安培 (A)。电压 (V) 是驱动电流的电势差，单位为伏特 (V)。电阻 (R) 阻碍电流，单位为欧姆 (Ω)。
V = I × R
Power (P) in a circuit is the product of voltage and current. The same power can be delivered at high voltage and low current to reduce losses.
功率 (P) 是电路中电压与电流的乘积。相同功率可以用高电压低电流来输送以减少损耗。
P = I × V
Kirchhoff's current law (KCL) says the total current entering a junction equals the total current leaving it. Kirchhoff's voltage law (KVL) states that the sum of voltages around any closed loop is zero.
基尔霍夫电流定律 (KCL) 说明流入节点的总电流等于流出节点的总电流。基尔霍夫电压定律 (KVL) 指出沿任一闭合回路的电压代数和为零。
A potential divider uses two resistors to scale down a voltage. The output voltage across R₂ is given by the ratio.
分压器 使用两个电阻来按比例降低电压。R₂两端的输出电压由该比值决定。
Vₒᵤₜ = Vᵢₙ × (R₂ / (R₁ + R₂))
Transducers convert one form of energy into another. Input transducers (sensors) like thermistors and LDRs change resistance with temperature or light. Output transducers (actuators) like LEDs and buzzers produce light or sound.
换能器 将一种能量形式转换为另一种。输入换能器 (传感器) 如热敏电阻和光敏电阻随温度或光照改变电阻。输出换能器 (执行器) 如LED和蜂鸣器产生光或声音。
6. Circuits and Components | 电路与元器件
Selecting and connecting components correctly determines the functionality and reliability of electronic subsystems. Students must recognise schematic symbols and real-world packages.
正确选择和连接元器件决定了电子子系统的功能性与可靠性。学生必须认识电路符号和实际封装。
Resistor limits current and divides voltages. Its value is shown with colour bands. Capacitor stores charge and smooths voltage variations.
电阻器 限制电流并分压。其阻值用色环表示。电容器 储存电荷并平滑电压波动。
Diode allows current to flow in only one direction. A light-emitting diode (LED) emits light and requires a series resistor for current limiting.
二极管 只允许电流单向流动。发光二极管 (LED) 会发光，需要串联电阻限流。
Transistor acts as a switch or amplifier. An NPN transistor turns on when a small base current flows, switching a larger collector-emitter current.
晶体管 用作开关或放大器。NPN型晶体管在基极有小电流流过时导通，从而切换更大的集电极-发射极电流。
Thermistor is a temperature sensor; an NTC type decreases resistance as temperature rises. Light-dependent resistor (LDR) lowers resistance in bright light.
热敏电阻 是温度传感器；负温度系数 (NTC) 型随温度升高电阻下降。光敏电阻 (LDR) 在强光下电阻降低。
Series circuit has one path for current; current is the same everywhere, voltage divides. Parallel circuit offers multiple paths; voltage is the same across branches, current divides. Understanding total resistance calculations is vital.
串联电路 只有一条电流路径，各处电流相等，电压分配。并联电路 提供多条路径，各支路电压相同，电流分配。理解总电阻的计算很重要。
Series: Rₜ = R₁ + R₂ + ... Parallel: 1/Rₜ = 1/R₁ + 1/R₂ + ...
7. Manufacturing Processes | 制造工艺
Different production volumes and materials demand specific processes. Year 12 covers conventional and modern methods, including CNC and additive manufacturing.
不同的产量和材料需要特定的工艺。12年级涵盖传统与现代方法，包括CNC和增材制造。
Casting pours molten metal into a mould; sand casting is versatile for large parts, die casting gives high accuracy for high volumes.
铸造 将熔融金属浇入模具；砂型铸造适用性广，适合大型件；压铸精度高，适于大批量。
Forging shapes metal using compressive forces, often hot, improving strength and grain structure. Rolling reduces thickness of slabs between rollers.
锻造 利用压缩力（通常热态）使金属成形，能提高强度和改善晶粒结构。轧制 通过轧辊减小板坯厚度。
Machining removes material with cutting tools. Turning uses a lathe for cylindrical shapes; milling uses rotating cutters for flat or complex surfaces; drilling creates holes.
机械加工 使用刀具切除材料。车削用车床加工圆柱形；铣削用旋转刀具加工平面或复杂曲面；钻削用于加工孔。
Welding joins metals by melting and fusing them, often with a filler. MIG and TIG are common arc welding processes. Brazing and soldering use a filler metal with a lower melting point than the base metals; soldering is typically for electronics and plumbing.
焊接 通过熔化并熔合金属
Published by TutorHao | Year 12 工程 Revision Series | aleveler.com
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