ENGR 220 Section 10.1 - 10.3
Plane Strain Review of Strain Deformation due to a stress is specified using the concept of normal and shear strain.
Normal Strain Elongation or contraction of a line segment per unit of length.
Shear Strain The change in angle the occurs between two line segments that were originally perpendicular.
Volume and shape deformations
Plane Strain
Strain Gauges
Strain Gauge
Strain Gauge http://www.youtube.com/watch?v=YBm_j232yUU&feature=related http://www.youtube.com/watch?v=TjY48vYMPxw
Strain Rosette
Generic Solution Strain measured along three axes at angles a b c Transform along x-y coordinates Stain Transformation Equations.
45˚ Strain Rosette
60˚ Strain Rosette
Principal Strains
Maximum In-Plane Shear Strain
Mohr’s Circle
Mohr’s Circle
Problem 10-2: Determine the in-plane strains of an element orientated at θ=20° counter-clockwise from the original position.
10.12 (10.3 8e) A strain gauge is mounted on the 1 inch diameter A-36 steel shaft as shown below. When the shaft is rotating with an angular velocity of 1760 rpm, the reading on the strain gauge is 800 (10-6). Determine the power output of the motor. Assume the shaft is subjected only to a torque.