MTS Series 609 Alignment Fixture - Manual (Page 47)

Calculating Bending Strain—Notched Round Thin
Series 609 Alignment Fixture Product Information Specimen Preparation 47
Where:
( φ) is measured from the highest reading (most tensile) strain
gage toward the second highest reading strain gage
b
1
is the highest strain reading of a given level
b
2
is the second highest reading of a given level
The bending strain directions for all levels should generally agree if you
have satisfactorily removed the “S” bend.
5. Calculate the maximum bending strain for each level.
Use this formula to find the maximum bending strain (B) at this gage level:
Where: Bu is the bending strain of the upper gages
Bl is the bending strain of the lower gages
b
1
is the highest strain reading of a given level
6. Calculate the percent bending strain for each level.
Use this formula to find the percent bending strain (PBS):
Where: Bu is the bending strain of the upper gages
Bl is the bending strain of the lower gages
Au is the average strain of the upper gages
Al is the average strain of the lower gages
Bu
b
1
θ cos
------------ = Bl
b
1
θ cos
------------ =
Upper Gages Lower Gages
PBS
Bu
Au
------- 100 × = PBS
Bl
Al
----- 100 × =
Upper Gages Lower Gages