A notched test specimen is subjected to tensile loading and a Constant Amplitude
Stress-Life Analysis is performed using OptiStruct.
The Stress-Life result from OptiStruct is compared with
the results from eFatigue
calculator, for the element 215576. Figure 1. Model with Loading Conditions
Model Files
Before you begin, copy the file(s) used in this problem
to your working directory.
The model is a test specimen of thickness 9.5 mm, subjected to tensile loading of
1150 N at circular holes, normal to the notch. The model was meshed with first-order
shell elements and the loading is applied to RBE3 elements that are connected to the
holes. The Signed Von Mises (SGVON) combined stress was used.
The material used is Steel RQC-100:
Material Properties
Value
Young's modulus
203000 MPa
Poisson's ratio
0.3
Ultimate tensile strength (UTS)
863.0 MPa
Fatigue strength coefficient (SRI1)
1101.0 MPa
First fatigue strength exponent (B1)
-0.075
Cycle limit of endurance for one segment SN curve (NC1)
1000000 cycles
A constant amplitude load is applied in the FATLOAD entry with a
scale factor of 14.1332, whose variation is:
Time Points
Load Curve Point
0
0.0
1
1.0
2
0.0
3
-1.0
4
0.0
Figure 2. Load Curve used in FATLOAD
All the modifying factors (Surface Roughness and Fatigue Strength Reduction factor)
are set to 1.0.
Results
Comparison of the Stress-Life results between OptiStruct
and eFatigue calculator for element 215576.
