Year 11 WJEC Engineering: Core Knowledge Review | 11年级WJEC工程核心知识点梳理

📚 Year 11 WJEC Engineering: Core Knowledge Review | 11年级WJEC工程核心知识点梳理

The WJEC GCSE Engineering course for Year 11 brings together design, materials, manufacturing, electronics, mechanics and systems thinking. This article revisits the essential knowledge you need for the examination, with each point presented in English and Chinese to strengthen your understanding and recall.

11年级WJEC GCSE工程课程融合了设计、材料、制造、电子、力学和系统思维。本文重温考试必备的核心知识，每个要点均以英文和中文对照呈现，帮助你加深理解与记忆。

1. Engineering Design Process | 工程设计流程

The design process starts with identifying a user need or design opportunity. This is captured in a design brief, followed by a detailed product specification listing measurable criteria such as dimensions, weight, materials and cost.

设计流程从识别用户需求或设计机会开始。这被记录在设计概要中，随后制定详细的产品规格，列出尺寸、重量、材料和成本等可测量标准。

Ideas are generated through brainstorming and sketching. A chosen concept is developed using CAD modelling, leading to a prototype. The prototype is tested against the specification and evaluated, often leading to iterative improvements before final production.

通过头脑风暴和草图产生创意。选定的概念使用CAD建模进行开发，然后制作原型。原型根据规格进行测试和评估，通常会在最终生产前进行迭代改进。

An engineering drawing must include orthographic views, dimensions and appropriate symbols to communicate the design clearly for manufacture.

工程图纸必须包含正交视图、尺寸和适当的符号，以便清晰地传达制造信息。

2. Materials and Their Properties | 材料及其性能

Ferrous metals contain iron and are magnetic. Mild steel is tough and easily welded, while cast iron is hard but brittle. Both can rust if not protected.

黑色金属含铁且有磁性。低碳钢韧性好、易焊接，而铸铁硬度高但脆。两者若不防护均会生锈。

Non-ferrous metals, such as aluminium and copper, do not contain iron, are non-magnetic and often resist corrosion well. Aluminium is lightweight, and copper has excellent electrical conductivity.

有色金属，如铝和铜，不含铁，无磁性，通常耐腐蚀性良好。铝重量轻，铜具有优异的导电性。

Polymers fall into thermoplastics (can be reheated and reshaped, e.g. acrylic, ABS) and thermosets (cannot be remoulded, e.g. epoxy resin, melamine). Composites like carbon fibre reinforced polymer (CFRP) combine high strength with low weight.

聚合物分为热塑性塑料（可重新加热成型，如亚克力、ABS）和热固性塑料（不可重新模塑，如环氧树脂、三聚氰胺）。复合材料如碳纤维增强聚合物兼具高强度与低重量。

Material / 材料	Key Properties / 主要性能
Mild steel 低碳钢	Tough, ductile, magnetic 坚韧、延展性好、有磁性
Aluminium 铝	Lightweight, corrosion-resistant 轻质、耐腐蚀
Acrylic 亚克力	Transparent, easily moulded thermoplastic 透明、易成型的热塑性塑料
CFRP / 碳纤维增强塑料	High strength-to-weight ratio 高强度重量比

3. Manufacturing Techniques | 制造技术

Traditional machining includes turning on a lathe to produce cylindrical parts and milling to create flat surfaces and slots. Drilling creates round holes using a rotating bit.

传统机械加工包括车床车削以生产圆柱形零件，以及铣床铣削以加工平面和槽。钻孔使用旋转钻头加工圆孔。

Casting involves pouring molten metal into a mould; sand casting is common for complex shapes. Welding joins metals by melting the edges, often using MIG or TIG processes.

铸造涉及将熔融金属浇注到模具中；砂型铸造常用于复杂形状。焊接通过熔化边缘来连接金属，通常采用MIG或TIG工艺。

Modern manufacturing uses CNC (Computer Numerical Control) machines for high accuracy and repeatability. Additive manufacturing, or 3D printing, builds parts layer by layer and allows complex geometries not possible with subtractive methods.

现代制造使用CNC（计算机数控）机床实现高精度和可重复性。增材制造，即3D打印，逐层构建零件，能够实现减材方法无法实现的复杂几何形状。

4. Electronic Systems and Components | 电子系统与元器件

Resistors limit current and are identified by colour codes. Fixed resistors have a set value, while variable resistors (potentiometers) allow adjustment. The resistance unit is the ohm (Ω).

电阻器限制电流，通过颜色代码识别。固定电阻器有确定阻值，而可变电阻器（电位器）可调节。电阻单位为欧姆 (Ω)。

Ohm’s law governs the relationship between voltage, current and resistance:

欧姆定律描述了电压、电流和电阻之间的关系：

V = I × R

A potential divider uses two resistors to obtain a fraction of the input voltage. The output voltage is given by:

分压器使用两个电阻器获得输入电压的一部分。输出电压公式为：

V_out = V_in × R₂ / (R₁ + R₂)

Diodes allow current to flow in one direction only. LEDs emit light when forward-biased. Transistors can act as electronic switches; a small base current controls a larger collector current, enabling automation and signal amplification.

二极管只允许电流单向流动。LED在正向偏置时发光。晶体管可作为电子开关；微小的基极电流控制较大的集电极电流，从而实现自动化和信号放大。

5. Mechanical Systems and Motion | 机械系统与运动

Levers use a pivot (fulcrum) to amplify an effort force. The three classes of lever differ by the relative positions of effort, load and fulcrum. Mechanical advantage = load / effort.

杠杆利用支点来放大力。三类杠杆的区别在于力、负载和支点的相对位置。机械效益 = 负载 / 力。

Gears transmit rotary motion and can change speed, torque and direction. The gear ratio is calculated from the number of teeth:

齿轮传递旋转运动，并能改变速度、扭矩和方向。齿轮比由齿数计算：

Gear Ratio = T₂ / T₁ = N₁ / N₂

(where T is the number of teeth and N is the rotational speed). A small driver gear turning a larger driven gear increases torque but reduces speed.

(其中T为齿数，N为转速)。小主动齿轮带动大从动齿轮可增加扭矩但降低速度。

Pulley and belt systems transfer motion between shafts. A smaller pulley driving a larger one works similarly to gears, while chain and sprocket systems prevent slippage and are used in bicycles.

皮带轮系统在轴之间传递运动。小带轮驱动大带轮与齿轮类似，而链轮系统可防止打滑，常见于自行车。

6. Forces, Structures and Mechanics | 力、结构与力学

Stress measures the internal force per unit area within a material when an external load is applied:

应力衡量材料在外部载荷作用下单位面积所受的内力：

σ = F / A

Strain is the deformation per unit length:

应变是单位长度的变形量：

ε = ΔL / L

Young’s modulus (E = σ / ε) describes stiffness. A high modulus means a material resists stretching.

杨氏模量 (E = σ / ε) 描述刚度。模量高意味着材料抗拉伸能力强。

The moment of a force about a pivot is the turning effect:

力对支点的矩是转动效应：

Moment = Force × perpendicular distance from pivot

For equilibrium, the sum of clockwise moments must equal the sum of anticlockwise moments. Structures such as trusses use triangulation to remain rigid under load.

为保持平衡，顺时针力矩之和必须等于逆时针力矩之和。桁架等结构利用三角形刚架在负载下保持刚性。

7. Pneumatics and Hydraulics | 气动与液压

Pneumatic systems use compressed air to transmit force. Key components include a compressor, valves, actuators (cylinders) and tubing. A single-acting cylinder extends with air pressure and returns by a spring.

气动系统使用压缩空气传递力。关键部件包括压缩机、阀、执行器（气缸）和管路。单作用气缸在气压下伸出，由弹簧复位。

Hydraulic systems use an incompressible fluid, usually oil, to achieve higher forces. They operate on Pascal’s principle, where pressure applied anywhere in an enclosed fluid is transmitted equally throughout.

液压系统使用不可压缩的流体（通常为油）以获得更大的力。它们基于帕斯卡原理运行，即在封闭液体中任何地方施加的压力都会均匀传递。

Pressure is force per unit area: P = F / A. A small force on a small piston can generate a large force on a larger piston, which is the foundation of hydraulic jacks and brakes.

压力等于力除以面积：P = F / A。施加在小活塞上的小力可在大活塞上产生大力，这是液压千斤顶和制动器的基础。

8. Systems and Control | 系统与控制

An open-loop system operates without feedback. For example, a simple timer-based toaster runs for a set time regardless of the toast’s colour. Closed-loop systems use feedback from sensors to adjust the output automatically, such as a thermostat maintaining room temperature.

开环系统无反馈运行。例如，简单的定时烤面包机按设定时间运行，而不考虑面包颜色。闭环系统利用传感器反馈自动调节输出，例如恒温器保持室温。

Microcontrollers (e.g. PICAXE) can be programmed to read inputs from switches, light sensors, or temperature sensors and control outputs like motors, LEDs and buzzers. Flowcharts using standard symbols (start/stop, process, decision) are used to plan control programs.

微控制器（如PICAXE）可编程读取来自开关、光传感器或温度传感器的输入，并控制电机、LED和蜂鸣器等输出。使用标准符号（开始/结束、处理、判断）绘制的流程图用于规划控制程序。

Important flowchart symbols: a rounded box for start or end, a rectangle for a process, and a diamond for a decision (yes/no). These translate directly into program code.

重要的流程图符号：圆角框表示开始或结束，矩形表示处理，菱形表示判断（是/否）。这些直接转换为程序代码。

9. Testing and Quality Assurance | 测试与质量保证

Products must be tested to ensure they meet the specification. Destructive testing, such as tensile or impact tests, breaks the sample to understand material limits. Non-destructive testing (NDT) includes visual inspection, dye penetrant, and ultrasonic methods to find surface or internal flaws without damaging the part.

产品必须经过测试以确保符合规格。破坏性测试，如拉伸或冲击测试，通过破坏样品来了解材料极限。无损检测包括目视检查、着色渗透和超声波方法，可在不损坏零件的情况下发现表面或内部缺陷。

Quality control (QC) involves inspecting finished products against standards, often using go/no-go gauges and measuring instruments. Tolerance is the allowable variation from a nominal size, e.g. 20 mm ±0.1 mm.

质量控制涉及依据标准检查成品，通常使用通止规和测量仪器。公差是相对于公称尺寸的允许偏差，例如20 mm ±0.1 mm。

Quality assurance (QA) covers the whole production process, from supplier checks to staff training and documentation, aiming to prevent defects rather than just detect them.

质量保证涵盖整个生产过程，从供应商审查到员工培训和文件记录，目的是预防缺陷而不仅仅是检测缺陷。

10. Health, Safety and Sustainability | 健康、安全与可持续性

In the workshop and on site, personal protective equipment (PPE) must be worn. This includes safety glasses, steel-toe boots, ear defenders and gloves appropriate to the task. Risk assessments identify hazards and control measures to reduce risks.

在车间和现场，必须穿戴个人防护装备。包括安全眼镜、钢头靴、耳罩和适合任务的手套。风险评估识别危险源并采取控制措施以减少风险。

COSHH (Control of Substances Hazardous to Health) regulations require the safe storage and handling of chemicals, adhesives, paints and dust. Good ventilation and correct disposal are essential.

COSHH（有害健康物质控制）法规要求安全储存和处理化学品、粘合剂、油漆和粉尘。良好的通风和正确处置必不可少。

Engineers must consider environmental impact through the 6Rs: Reduce, Reuse, Recycle, Repair, Refuse and Rethink. Life cycle assessment (LCA) evaluates a product’s environmental footprint from raw material extraction to disposal, helping designers choose more sustainable materials and processes.

工程师必须通过6R原则考虑环境影响：减少、重用、回收、修复、拒绝和反思。生命周期评估从原材料提取到废弃处置评估产品的环境足迹，帮助设计师选择更可持续的材料和工艺。

Published by TutorHao | Engineering Revision Series | aleveler.com

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Year 11 WJEC Engineering: Core Knowledge Review | 11年级WJEC工程核心知识点梳理