PSI - Issue 38

Alexander Erbe et al. / Procedia Structural Integrity 38 (2022) 192–201 Author name / Structural Integrity Procedia 00 (2021) 000 – 000

196

5

Table 2 summarizes a selection of the experiments performed. For a test-temperature of 400 °C two defined equivalent strain ranges (DP) were tested. For classification and reference purpose, LCF-experiments using a uniaxial standard type specimens have also been carried out. Experiments with the isothermal temperature of 500 °C cover one common strain range. In addition, the influence of dwell times has been investigated by carrying out the tests with the same loading parameters but with a holding time of three minutes in tension and compression. All experiments were carried out with a load ratio R of -1 and a strain rate based on von Mises equivalent strain of 6 % / min.

Table 2: Strain controlled experiments at T=400 °C with different axis ratios, cycles are normalized with uniaxial lifetime

Test mark

Temper ature [°C]

Control condition

Axis Ratio

v. Mises equivalent strain range

Ext. strain amplitude Axis A [%]

Ext. strain amplitude Axis B [%]

Normalized cycles at 5% load drop

Dwell time ten./comp. [min]

Δε

Δε eq,HS

eq,DP

sGZ4d2

400 400 400 400 400 400 400 400 400 400

Strain Strain Strain Strain Strain Strain Strain Strain Strain Strain

Uniaxial

Δε Δε Δε Δε Δε

Δε

1.00 0.99 0.60 1.16 3.50 1.00 2.06 0.88 0.99 2.89

0 / 0 0 / 0 0 / 0 0 / 0 0 / 0 0 / 0 0 / 0 0 / 0 0 / 0 0 / 0

sGZ4df11 sGZ4df8 sGZ4df12 sGZ4df7 sGZ4d3 sGZ4df3 sGZ4df4 sGZ4df6 sGZ4df5

1.0 0.0

1.02 Δε 1.17 Δε 1.02 Δε 1.0 Δε 1.33 Δε 1.38 Δε 1.64 Δε 1.4 Δε 1.38 Δε

0.198 0.315 0.286 0.230 0.252 0.419 0.195 0.315

0.198

0.00

-0.5 -1.0

-0.143 -0.230

Uniaxial

1.33 Δε 1.33 Δε 1.33 Δε 1.33 Δε 1.33 Δε

1.0 0.0

0.252

0.00

-0.5 -1.0

-0.389 -0.315

Table 3: Strain controlled experiments at T=500 °C with different axis ratio, cycles are normalized with uniaxial lifetime

Test mark

Temper ature [°C]

Control condition

Axis Ratio

v. Mises equivalent strain range

Ext. strain amplitude Axis A [%]

Ext. strain amplitude Axis B [%]

Normalized cycles at 5% load drop

Dwell time ten./comp. [min]

Δε

Δε eq,HS

eq,DP

sGZ5d1 sGZ5df1 sGZ5df2 sGZ5df4 sGZ5df3 sGZ5dhf3 sGZ5dhf4 sGZ5dhf2 sGZ5dhf5

500 500 500 500 500 500 500 500 500

Strain Strain Strain Strain Strain Strain Strain Strain Strain

Uniaxial

Δε Δε Δε Δε Δε Δε Δε Δε Δε

Δε

1.0

0 / 0 0 / 0 0 / 0 0 / 0 0 / 0 3 / 3 3 / 3 3 / 3 3 / 3

1.0 0.0

1.03 Δε 1.30 Δε 1.03 Δε 1.02 Δε 1.03 Δε 1.30 Δε 1.03 Δε 1.02 Δε

0.195 0.319 0.289 0.232 0.195 0.319 0.289 0.232

0.195

2.28 0.55 0.96 4.37 0.83 0.22 0.50 1.50

0.00

-0.5 -1.0

-0.145 -0.232 0.195

1.0 0.0

0.00

-0.5 -1.0

-0.145 -0.232