Lab #5 Due Today Individual Data Processing and Individual Write Up Lab #5 Report is due TODAY by midnight Answer Multiple Choice Questions ONLINE TODAY by midnight Answer Student Survey ONLINE TODAY by midnight Submit the Lab Report #5 in the drawer labeled “MECE – 204: Strength Lab” beneath the M. E. Mail Folders

Lab #5 Report due Today Cover Page + Abstract Data Sheet Spreadsheet Plot #1: h versus W Plot #2: Gradient vs. a2 Material Property Tables (two tables) Comments and Conclusions

Combined Loading Test Review Poisson’s Ratio, Bending, Torsion Superposition Principle in Combined Loading Strain Rosette and Equations Strains from Stresses Principal Stresses and Maximum In-plane Shear Stress

Review Poisson’s Ratio

Poisson’s Contraction

Review Bending Consider the top surface: Longitudinal Contraction Therefore, Transverse Expansion

Bending Stress and Strains z = -x

Deformation in Torsion Two torques are applied Circles remain circles Longitudinal lines become twisted All angles are equal End x-section remains flat

Shear Strain in Torsion FG05_01-02UN.TIF Notes: Notice the deformation of the rectangular element when this rubber bar is subjected to a torque. After Before 9

Shear Stress & Torque

Combined Loading

Both Bending & Torsion

Stresses and Strains Bending Torsion Round x-section x = FLbendc/I xz = FLarmc/J c = D/2 x = x /E xz = xz /G I = D4/64 z = - x G = E/(2+2) J = 2 I

Stress State under Strain Gage

45 Strain Rosette & Strain Transformations In our case: Gage B is aligned along x (axial direction) Substitute  = -45, 0, +45 for A, B, C gages And solve for the three strains:

Mohr’s Circle & Stress Transformations

Conduct the Combined Loading Test Please initialize the Strain Meter a couple of times to ensure that it indicates zero strains at zero load, and that there is NO DRIFT with time

Bending Only (Equations) M = F * Lbend x = FLbendc/I c = D/2 I = D4/64

Bending Only (Spreadsheet)

Elastic Modulus

Poisson’s Ratio

Properties (Bending Only)

Combined Loading (Stress Analysis) x = F * Lbend * c/I z = 0 xz = F * Larm * c/J

Stress Analysis (Spreadsheet)

Strain Analysis (Equations) x = x / E z = -  * x xz = xz / G

Strain Analysis (Spreadsheet)

Longitudinal Strain (Plot)

Transverse Strain (Plot)

Shear Strain (Plot)

Lab #5 Due Today Individual Data Processing and Individual Write Up Lab #5 Report is due TODAY by midnight Answer Multiple Choice Questions ONLINE TODAY by midnight Answer Student Survey ONLINE TODAY by midnight Submit the Lab Report #5 in the drawer labeled “MECE – 204: Strength Lab” beneath the M. E. Mail Folders