Jiangyu Li, University of Washington Lecture 16 Torsion Mechanical Behavior of Materials Section...

Jiangyu Li, University of Washington

Lecture 16Torsion

Mechanical Behavior of Materials Section 4.9.3-4.9.4Discussion on the torsion test posted online

Jiangyu LiUniversity of Washington

Mechanics of Materials Lab

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Fig. 3-3 Deformations of a circular bar in pure torsion.

Angle of Twist

Jiangyu Li, University of Washington

Fig. 3-4 Deformation of an element of length dx cut from a bar in torsion.

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Fig. 3-5 Shear strains in a circular tube.

Shear Strain

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Shear Stress

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Fig. 3-7 Longitudinal and transverse shear stresses in a circular bar subjected to torsion.

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Torque

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Fig. 3-10 Circular tube in torsion.

Jiangyu Li, University of Washington©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Fig. 3-20 Stresses acting on a stress element cut from a bar in torsion (pure shear).

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Principal Stress

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Fig. 3-25 Strains in pure shear: (a) shear distortion of an element oriented at = 0, and (b) distortion of an element oriented at = 45°.

Jiangyu Li, University of Washington

Torsion Test

Jiangyu Li, University of Washington

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Fig. 3-24 Torsion failure of a brittle material by tension cracking along a 45° helical surface.