《材料力学》课程PPT教学课件（双语版）第三章 扭转

Mechanics of materials CHAPTER3

1 Mechanics of Materials

料力

2

CHAPER 3 TORSION □§3-1 SUMMARY D33-2 EXTERNAL TORQUE OF A TRANSMISSION SHAFT INTERNAL TORQUE AND DIAGRAMS DIS3-3 TORSION OF THIN-WALLED HOLLOW SHAFTS DIS3-4 STRESSES OF CIRCULAR SHAFTS IN TORSION. STRENGTH CONDITIONS □」§3-5 DEFORMATIONS OF A CIRCULAR SHAFT IN TORSION· RIGIDITY CONDITIONS >33-6 STATICALLY INDETERMINATE PROBLEMS OF CIRCULAR SHAFTS IN TORSION DS3-7 STAIN ENERGY OF CIRCULAR SHAFTS IN TORSION DS3-8 STRESSES AND DEFORMATIONS OF NONCIRCULAR SHAFTS IN FREE TORSION D83-9 STRESSES OF OPENED AND CLOSED RODS WITH THIN WALLED SECTIONS IN FREE TORSION

3 §3–1 SUMMARY §3–2 EXTERNAL TORQUE OF A TRANSMISSION SHAFT INTERNAL TORQUE AND DIAGRAMS §3–3 TORSION OF THIN-WALLED HOLLOW SHAFTS §3–4 STRESSES OF CIRCULAR SHAFTS IN TORSION · STRENGTH CONDITIONS §3–5 DEFORMATIONS OF A CIRCULAR SHAFT IN TORSION · RIGIDITY CONDITIONS §3–6 STATICALLY INDETERMINATE PROBLEMS OF CIRCULAR SHAFTS IN TORSION §3–7 STAIN ENERGY OF CIRCULAR SHAFTS IN TORSION §3–8 STRESSES AND DEFORMATIONS OF NONCIRCULAR SHAFTS IN FREE TORSION §3–9 STRESSES OF OPENED AND CLOSED RODS WITH THIN WALLED SECTIONS IN FREE TORSION CHAPER 3 TORSION

第三章扭转 回§3-1概述 §3-2传动轴的外力偶矩·扭矩及扭矩图 §33薄壁圆筒的扭转 p§3-4等直圆杆在扭转时的应力·强度条件 回§3-5等直圆杆在扭转时的变形·刚度条件 §36等直圆杆的扭转超静定问题 §3-7等直圆杆在扭转时的应变能 D§38非圆截面等直杆在自由扭转时的应力和变形 §39开口和闭口薄壁截面杆在自由扭转时的应力

4 §3–1 概述 §3–2 传动轴的外力偶矩 · 扭矩及扭矩图 §3–3 薄壁圆筒的扭转 §3–4 等直圆杆在扭转时的应力 · 强度条件 §3–5 等直圆杆在扭转时的变形 · 刚度条件 §3–6 等直圆杆的扭转超静定问题 §3–7 等直圆杆在扭转时的应变能 §3–8 非圆截面等直杆在自由扭转时的应力和变形 §3–9 开口和闭口薄壁截面杆在自由扭转时的应力 第三章 扭 转

TORSION S3-1 SUMMARY Shaft: In engineering the members of which deformations are mainly torsion Such as transmission shafts in machines drill rods in oil-drilling rigs etc Torsion: Resultant of the external forces is a force couple and its acting plane is perpendicular to the axis of the shaft. Under this case the deformation of the rod is torsion B A O

5 §3–1 SUMMARY Shaft：In engineering the members of which deformations are mainly torsion. Such as transmission shafts in machines, drill rods in oil-drilling rigs etc. Torsion：Resultant of the external forces is a force couple and its acting plane is perpendicular to the axis of the shaft. Under this case the deformation of the rod is torsion. A B O m m  O B A 

§3-1概述 轴:工程中以扭转为主要变形的构件。如:机器中的传动轴、 石油钻机中的钻杆等。 扭转:外力的合力为一力偶,且力偶的作用面与直杆的轴线 垂直,杆发生的变形为扭转变形。 B A O

6 §3–1 概 述 轴：工程中以扭转为主要变形的构件。如：机器中的传动轴、 石油钻机中的钻杆等。 扭转：外力的合力为一力偶，且力偶的作用面与直杆的轴线 垂直，杆发生的变形为扭转变形。 A B O m m  O B A 

TORSION The angle of twist (): The angle of rotation of one section with respect to another Shearing strain(r): The change of a right angle between two straight lines OBm

7 The angle of twist ()：The angle of rotation of one section with respect to another . Shearing strain ( )：The change of a right angle between two straight lines. m m  O B A 

扭转角(φ):任意两截面绕轴线转动而发生的角位移 剪应变(y):直角的改变量。 O 8

8 扭转角（）：任意两截面绕轴线转动而发生的角位移。 剪应变（）：直角的改变量。 m m  O B A 

TORSION 20N lxer 80 fixer 2n0 N 10 Boxed cantilever beam Practical examples in engineering B ⑩⑥ T B A 0 T喂游 ssion shaft

9 Practical examples in engineering Transmission shaft

20N 团怠 程 实 120 定 例 0 TACN 箱式悬臂梁 r B (6 6⑥ B A 传动轴 0

10 工程实例