Fig. 1

Fuselage section for crashworthiness study

Fig. 2

Structure components of fuselage section

Fig. 3

Section view of fuselage section

Table 1

Summary of cracks on fuselage section

序号	裂纹位置	照片
1	左22框13长桁机身框
2	左23框14长桁机身框
3	左23框13长桁机身框
4	左23框12长桁机身框
5	左24框13长桁机身框
6	左24框14长桁机身框
7	左25框13长桁机身框
8	右25框13长桁机身框
9	右25框14长桁机身框
10	22-23框左1长桁-右1长桁蒙皮
11	24框右6长桁-右7长桁蒙皮

Fig. 4

Repair of cracks on frame

Fig. 5

Repair of cracks on skin

Fig. 6

Diagram of vertical drop test of fuselage

Fig. 7

Vertical drop test of typical aircraft fuselage section

Fig. 8

High-speed camera arrangement

Fig. 9

Mark arrangement

Fig. 10

Deformation of fuselage section after crash

Fig. 11

Deformation mode of fuselage structure after test

Fig.12

Ground impact load-time curve

Fig. 13

Vertical displacement-time curves of marks on beam

Fig. 14

Vertical vocity-time curves of marks on beam

Fig. 15

Model of fuselage section

Fig. 16

Repair areas of fuselage low part

Table 2

Material parameters of fuselage section［30］

Fig. 17

Comparison of fuselage structural deformation at peak load

Fig. 18

Comparison of ground load-time curves

Fig. 19

Comparison of displacement and velocity curves of marks on beam

Fig. 20

Deformation at repair area

Table 3

Summary of repair conditions

Fig. 21

Finite element models with repairs on skin

Fig. 22

Comparison of fuselage deformation with skin symmetrical repair

Fig. 23

Stress nephogram of fuselage with skin symmetrical repair

Fig. 24

Comparison of load-time curves of fuselage with skin symmetrical repair

Fig. 25

Comparison of peak load of fuselage with different repair areas （symmetrical repair of skin）

Fig. 26

Comparison of internal energy of fuselage with different repair areas （symmetrical repair of skin）

Fig. 27

Comparison of fuselage deformation with skin asymmetrical repair

Fig. 28

Stress nephogram of fuselage with skin asymmetrical repair

Fig. 29

Comparison of load-time curves of fuselage with skin asymmetrical repair

Fig. 30

Comparison of peak load of fuselage with different repair areas （asymmetrical repair of skin）

Fig. 31

Comparison of internal energy of fuselage with different repair areas （asymmetrical repair of skin）

Fig. 32

Finite element models with repairs on frame

Fig. 33

Comparison of fuselage deformation with framesymmetrical repair

Fig. 34

Stress nephogram of fuselage with frame symmetrical repair

Fig. 35

Comparison of load-time curves of fuselage with frame symmetrical repair

Fig. 36

Comparison of peak load of fuselage with different repair areas （symmetrical repair of frame）

Fig. 37

Comparison of internal energy of fuselage with different repair areas （symmetrical repair of frame）

Fig. 38

Comparison of fuselage deformation with frame asymmetrical repair

Fig. 39

Stress nephogram of fuselage with skin asymmetrical repair

Fig. 40

Comparison of load-time curves of fuselage with frame asymmetrical repair

Fig. 41

Comparison of peak load of fuselage with different repair areas （asymmetrical repair of frame）

Fig. 42

Comparison of internal energy of fuselage with different repair areas （asymmetrical repair of frame）