1. Lesson 12 Engineering Materials
每一张的背景相同，但内容不同。比如说每一课的第一页----标题页必须插入一幅与标题内容相关的图片，图片大小如上。

2. Contents
Material properties
Testing of materials
此页为目录页，把课文的主要内容概括一下。

3. Lead-in The ship TITANIC was being built. TITANIC
The sinking of the super-ship related closely to the quality of the materials.

4. The result of impact test of the plate used by Titanic and one modern ship respectively.
Plate used by one modern ship

5. Romance?
Tragedy!
此页和下页为课文的导入部分，我用的是铁达尼号沉没和船舶油污染的图片而展开讨论，进而引出船舶双层底的作用。

6. Material properties Tensile strength Ductility Brittleness
Malleability
Plasticity
Elasticity
Toughness
Hardness

7. Testing of materials
Stress---The force acting on a unit area of the material.
Strain--- The deforming of a material due to stress.

8. Tensile test The result of tensile test.
To measure a material’s strength and ductility.
Factor of safety=UTS/working stress
The result of tensile test.

9. Impact test
The test measures energy absorbed by a material when it is fractured.

10. Hardness test
The test measures a material’s resistance to indentation.
布氏硬度计

11. Creep test
The slow plastic deformation of a material under a constant series.

12. Fatigue test
A limiting fatigue stress or fatigue limit for a material.
轴的疲劳断口
疲劳辉纹（扫描电镜照片）

13. Bend test---To determine the utility of a material.
Non-destructive testing.

14. Language knowledge Compressive stress Shear stress Brittleness
tensile stress
Shear stress
Brittleness
Toughness
Hardness
Carelessness
从此页开始为单词学习部分，可根据情况对课文的单词进行扩充并辅以图片。

15. Assignment Memorize the language points . Extended readings
Try to differentiate compressive stress, tensile stress and shear stress.