136
L. Chen et al.
Table 1. Material parameters
Density (kg/m 3 )
Young’s modulus (Gpa)
Poisson’s ratio
Femur [13]
180000
0.7
0.3
Airbag
1150
8.3
0.28
Table 2. Finite element model
Unit number Node number Unit type
Land 31250
31626
R3D4 Rectangular shell element
Femur 24339
37133
C3D10M 10 node correction twice for 4 hedron element
Airbag 25480
25114
S4R Quadrilateral shell element
S3 Triangular shell element
Fig. 5. Stress cloud image of femur with airbag
Fig. 6. Stress cloud image of femur without airbag
The impact force response curves are shown in Fig. 7. The impact force on the femur
increased rapidly and reached a peak after contact in both models, and decreased to 0 at
the end of the impact. With airbag, the peak of impact force, which is 2979 N, occurs at
0.3 s; without airbag, the peak of impact force occurs at 0.30 s and the value is 49000 N.
The peak of the impact was significantly reduced by 94%. In addition, in the case with
L. Chen et al.
Table 1. Material parameters
Density (kg/m 3 )
Young’s modulus (Gpa)
Poisson’s ratio
Femur [13]
180000
0.7
0.3
Airbag
1150
8.3
0.28
Table 2. Finite element model
Unit number Node number Unit type
Land 31250
31626
R3D4 Rectangular shell element
Femur 24339
37133
C3D10M 10 node correction twice for 4 hedron element
Airbag 25480
25114
S4R Quadrilateral shell element
S3 Triangular shell element
Fig. 5. Stress cloud image of femur with airbag
Fig. 6. Stress cloud image of femur without airbag
The impact force response curves are shown in Fig. 7. The impact force on the femur
increased rapidly and reached a peak after contact in both models, and decreased to 0 at
the end of the impact. With airbag, the peak of impact force, which is 2979 N, occurs at
0.3 s; without airbag, the peak of impact force occurs at 0.30 s and the value is 49000 N.
The peak of the impact was significantly reduced by 94%. In addition, in the case with