DRILL BIT FATIGUE LIFE ESTIMATEFEA SIMULATION

REV A 12/11/17

D. BLANCHET

3B ASSOCIATES

23 ROCKY HILL RD.

BURLINGTON, MA 01803

781-272-7057

DWB3298@OUTLOOK.COM

PREPARED FOR: I. TIMOSHENKO

0.375 DIA TOOL STEEL

SOLIDWORKS MODEL INCLUDING SMALL DEFECT

FEA REFINED MESH – 4 ADAPTIVE STEPSNEAR EXPECTED STRESS CONCENTRATIONS

APPLIED BOUNDARY CONDITIONS

Fixed in chuck

Side loading components

From cutting

Reaction forces

STATIC STRESS ANALYSIS – MAX BELOW FRACTUREMISALIGNMENT “WOBBLE” 0.0035 INCH

DRILL WOBBLE .0035CAUSE OF ALTERNATING

TENSILE AND COMPRESSIVE

STRESSES – INDUCINGFATIGUE FAILURE

FATIGUE LIFE S-N CURVE

FATIGUE LIFEESTIMATEFROM FEA

AT 800 RPM

1.6E04/800 =20 MINUTES