Issue 74

D. D’Andrea et alii, Fracture and Structural Integrity, 74 (2025) 294-309; DOI: 10.3221/IGF-ESIS.74.18

s

*   t

 

CI

(12)

95% lim,STM

n

lim σ [MPa] STM - Predicted

lim σ [MPa] STM - Calculated

Student’s t - * t

95% CI [MPa] - Calculated

Observations number - n

Material

30.1 29.3 28.0 25.5 27.2 27.8 28.0

31.7 29.7 28.7 30.5 31.4 28.6 30.9

30.1 2.0 

Nylon CF

4

3.182

30.3 3.7 

PA12 (MJF)

3

4.303

201.0 212.0 200.0

204.5 247.4 206.3

219.4 60.3 

AISI 316L

3

4.303

Table 1: STM experimental report. Fig. 11 shows stabilization temperature vs. stress amplitude during a stepwise test executed at 1 Hz and load ratio of 0.1. Fatigue limit is calculated as the intersection of the two straight lines interpolating experimental thermographic data for stresses below and above the fatigue limit as explained by Luong [21]and Curà et al. [22].

Figure 10: Static Thermographic Method’s result for PA12-MJF.

304