Fig.1

Construction of life design method based on dual-scale damage theory

Fig. 2

Schematic of hysteresis loop

Fig.3

Schematic diagrams of two different fatigue indicator parameters

Fig.4

Research approaches of multi-scale theories from nano-scale to structure-scale

Fig.5

Schematic diagram of three common dual-scale modelling approaches［64］

Fig.6

Macro-scale finite element model and crystal plasticity finite element model of notched structure

Fig.7

Comparison in calculation efficiency for the three dual-scale modelling approaches［64］

Fig.8

Comparisons of three dual-scale modelling approaches

Table 1

Comparison of three dual-scale modelling approaches

Fig.9

Overall flow chart of dual-scale modelling approach for predicting creep-fatigue crack initiation life

Fig.10

Finite element modelling approach

Fig.11

Comparison between experimental data and simulated results based on macro- and micro- constitutive models

Fig.12

Accumulated plastic deformation of hole structure

Fig.13

Evolution of accumulated energy dissipation based on micro-scale model

Fig.14

Comparisons between experimental creep-fatigue life and predicted results for hole structure

Fig.15

Water-jet technology for life improvement

Fig.16

Overall flowchart for creep-fatigue life assessment of surface strengthening notch structure

Fig.17

Investigation of crack initiation mechanisms for surface strengthening notch structure［100］

Fig.18

Construction of surrogate model for life prediction

Table 2

Distribution of input parameters related to residual stress and plastic layer

Fig.19

Determination of the optimal parameters for BP neural network

Fig.20

Hyper-parameters optimization of machine learning models under cross-validation process

Fig.21

Comparison of life prediction results

Fig.22

Interface development of life prediction system based on surrogate model