Fig.1

Schematic diagram of a cohesive zone model

Fig.2

Early traction-separation laws

Fig.3

Typical TSLs

Fig.4

Influence of initial stiffness［18］

Fig.5

Normalized representative volume element （RVE） stress-strain curves under constant stress triaxiality［19］

Fig.6

Four different TSLs with identical cohesive parameters［23］

Fig.7

Load-displacement curves obtained from four TSLs［23］

Fig.8

Similarity of simulation results based on different TSL shapes［24］

Fig.9

Tunneling effects of crack front［24］

Table 1

Comparison of origins and applicability of different TSL shapes

Fig.10

Plane strain conditions［24］

Fig.11

Parameter calibration under plane stress conditions［24］

Fig.12

Plane stress conditions［24］

Fig.13

Simulation results of 3D finite element［24］

Fig.14

Experimental and simulation results of notched tensile bars［24］

Fig.15

Determination of cohesive strength［25］

Fig.16

Three methods for determiningJi［25］

Fig.17

Effect of cohesive parameters on R-curves［25］

Fig.18

Influence of cohesive parameters on load versus crack extension curves［12］

Fig.19

Influence of cohesive parameters on tunneling effect［12］

Fig.20

Inverse method to determine cohesive energy and cohesive strength［29］

Fig.21

Cohesive elements［25］

Fig.22

Transition from normal fracture to slant fracture［9］

Fig.23

Finite element model of a cylindrical shell with circumferential stiffeners［48］

Fig.24

Two types of crack propagation behavior［48］

Fig.25

Schematic of five-stiffener integral panel［5］

Fig.26

Shell element model and predefined cohesive elements［5］

Fig.27

3D element model and predefined cohesive elements［5］

Fig.28

Comparison between experimental results and predictions from two models［5］

Fig.29

Normal stress contour of the ligament at maximum load［5］

Fig.30

Stress triaxiality distribution under three typical conditions［5］

Fig.31

Stress triaxiality contour of M（T） specimen［5］

Fig.32

Fuselage panel structure with a two-bay crack［9］

Fig.33

Location of inserted cohesive elements［9］

Fig.34

Normalized pressure versus crack extension at frames C3 and C5［9］

Fig.35

Friction stir welded dissimilar aluminum C（T） specimen［44］

Fig.36

Variation of the cohesive properties in the weld region［44］

Fig.37

Comparison between finite element simulation and experimental results under various loading conditions［44］