Structural Analysis of Human Body Impact
Young-Shin Lee
Dept. of Mechanical Design Engineering, Chungnam National University, Korea.
Young-jin Choi
Graduate School, Dept. of Mechanical Design Engineering, Chungnam National
University, Korea.
Se-Hoon Lee
Graduate School, Dept. of Mechanical Design Engineering, Chungnam National
University, Korea
Je-Wook Chae
Agency for Defense Development, Korea
Eui-Jung Choe
Agency for Defense Development, Korea
Abstract
The impact of firing a rifle on the human body is affected by human posture. The human model of shooting
posture is defined by the action of the shooter. The shooting impact of the rifle is transferred to the human
model. In this study a finite element analysis has been performed in order to investigate the impact on a
human body of shooting a rifle. The model (height 170 cm, weight 60 kg) is developed by the finite
element method using beam elements. The human body impulse is analyzed by the ANSYS 8.1 code. The
human impact analysis of a standing shooting posture, shooting from a kneeling posture and prone shooting
posture are investigated. In this study, the rifle used for the impulse analysis is a K2. The applied load for
the simulation inputs is about 4 kN. In the results, the displacement and stress on the human body is
presented.
Introduction
The rifle impulse in the soldier system is affected by the characteristics of the human body. The rifle
impulse affects fighting power and mission durability. This is a study on the rifle impulse of shooting
postures for soldier characteristic needs. The finite element model and the analysis method of the human
impulse need to analyze and to estimate the sensibility and the human impact limit. In this study, the impact
analysis of the human body creates the human modeling of Koreans and obtains both the impact force and
the applied load of each joint through a simulation of conditions that occur when shooting. The transfer
path of the impact is obtained by the analysis of the impact history.
Human modeling
For the human impact structural analysis, the human model of a shot is applied to a male model of 170 cm
height, 60 kg weight. For the creation of the stick model, the data as joint and segment length on the model
is measured. Figure 1 shows the stick model of three shooting postures. The stick model is used by
ADAMS/LIFEMOD. The analysis model for the ANSYS code is used by coordinate point and mass data of
the stick model. Figure 2 shows the analysis model of ADAMS and FE with the standing shooting posture.
Figure 3 shows the coordinate of segments with the three shooting postures. The coordinate is determined
by the human data of the shooter and the measurement of the shooting posture. For the analysis modeling,
the area of the segment is uniform along each axis. The analysis model consists of 19 cylindrical beam
segments. The elastic modulus of skeletal model, Poisson’s ratio and mass density is 20 GPa, 0.3 and 6210
kg/m3 respectively. Table 1 shows the dimension and material property of the analysis human model. For
the analysis model, the joint element between the two segments is applied to COMBIN7, COMBIN14 and
LINK11. The element of the segment is used to BEAM188.
(a) Stand posture
(b)Knee posture
(c) Prone posture
Figure 1. Comparison of model with the three shooting posture
(a)ADAMS stick model
(b)FE beam model
Figure 2. Analysis model of ADAMS and FE with the stand shooting posture
(a) Stand shooting posture
(b) Knee shooting posture
(c) prone shooting posture
Figure 3. Geometry of human body with typical shooting posture
Table 1 Material property for FE model
Mass (kg)
Length (m)
Area (mm2)
Radius (mm)
Foot
1.06
0.091
15.533
2.22
Lower Leg
2.20
0.335
118.680
6.15
Upper Leg
4.5
0.213
154.348
7.01
Lower Torso
5.26
0.086
72.844
4.82
4.03
0.068
44.129
3.75
9.02
0.307
445.916
11.92
1.4
0.129
29.082
3.04
Upper Arm
1.17
0.232
43.710
3.73
Lower
Arm
0.99
0.241
38.420
3.50
Hand
0.3
0.062
2.995
0.98
Neck
0.8
0.111
14.300
2.13
Head
4.09
0.055
36.224
3.40
Property
Central Torso
Upper Torso
Scapula
E : 20 GPa
ν
: 0.3
Density : 6210 kg/m3
Boundary condition and load condition
Figure 4 shows the input impulse data of FE analysis due to the K2 rifle testing. Figure 5 shows the
boundary condition and mesh shape of the human-rifle system with the standing shooting posture. For the
standing shooting posture, both feet are fixed to the ground. The boundary condition between the rifle
model and both hands is applied to the fixed condition. Between the rifle model and shoulder, the joint
element is used. Figure 6 shows the boundary condition and mesh shape of the human-rifle system with a
kneeling shooting posture. For the kneeling shooting posture, the right knee and both feet are fixed to the
ground. Figure 7 shows the boundary condition and mesh shape of the human-rifle system with a prone
shooting posture. For the prone shooting posture, both feet, both elbows and the lower body are fixed to the
ground. The load condition is applied to the measured data on the shooting tests [6]. The maximum impulse
is 4000 N at the 0.2 ms.
F (N)
4000
1500
800
0
0.2 0.5
0.9
1.4
t (ms)
3.0
Figure 4. Input data of FE analysis due to the K2 rifle testing
Figure 5. Boundary condition and mesh shape of human-rifle system with stand shooting
posture
Figure 6. Boundary condition and mesh shape of human-rifle system with knee shooting
posture
Figure 7. Boundary condition and mesh shape of human-rifle system with prone shooting
posture
Human body response
The most unstable posture in the three shooting postures is the standing shooting posture. The deformation
by the shooting impulse with the standing shooting posture occurred on the upper human body. The
displacement on the shoulder and lumbar is larger than on the other body parts. At 0.2 s after the standing
shooting, the displacement of longitudinal direction on the shoulder, clavicle, neck and wrist are 16.47 mm,
15.85 mm 14.67 mm and 15.90 mm, respectively. Figure 8 shows the deformation of human body model
with the standing shooting posture. The deformation by the shooting impulse on the kneeling shooting
posture occurred on the fixed human body. The maximum displacement happened on the lumber because
of the fixed condition of the elbow. At 0.2 s after kneeling shooting, the displacement of longitudinal
direction on the lumber is 13.50 mm. Figure 9 shows the deformation of the human body model with a
kneeling shooting posture. The prone shooting posture is the most stable posture of the three shooting
postures. The impulse caused by shooting transfers to the entire body. The maximum impulse happens on
the shoulder. At 0.2 s after the prone shooting, the displacement of longitudinal direction on the shoulder,
clavicle, neck and wrist are 0.22 mm, 0.28 mm 0.20 mm and 0.11 mm, respectively. Figure 10 shows the
deformation of the human body model with a prone shooting posture. Figure 11 shows the deformation of
the human body model with a standing shooting posture using ADAMS/LifeMOD. Table 2 shows the
maximum displacement of the human body with the standing shooting posture. The displacement result for
the finite element analysis is similar in the result for the dynamic analysis on the each human part.
Table 2 Maximum displacement of the human body with stand shooting posture
ADAMS/LifeMOD Simulation result
ANSYS result
Right shoulder
16.81 mm
16.47 mm
Right scapula
11.20 mm
15.85 mm
Neck
10.72 mm
14.67 mm
Right wrist
16.35 mm
15.90 mm
Figure 8. Deformation of human body model with stand shooting posture
Figure 9. Deformation of human body model with knee shooting posture
Figure 10. Deformation of human body model with prone shooting posture
Figure 11. Deformation of human body model with stand shooting posture using
ADAMS/LifeMOD
Human body Stress response
The most unstable posture of the three shooting postures is the standing shooting posture. At 0.2 ms after
shooting, the stress on the shoulder are 1.30 MPa, 8.96 MPa and 9.87 MPa, respectively in the standing
shooting posture, the kneeling shooting posture and the prone shooting posture. On the lumber, the stress
with the standing shooting posture, the kneeling shooting posture and the prone shooting posture are 1.28
MPa, 0.90 MPa and 4.48 MPa, respectively. In the result of the impact transfer path analysis with the
standing shooting posture, the initial stress is on the shoulder at 0.2 ms. At 0.5 ms after shooting, stress
occurs on the right humerus and scapular. At 0.9 ms after shooting, stress occurs on the right forearm and
thoracic. At 1.4 ms after shooting, stress occurs on the right upper body. The impulse by shooting is
transferred to the left hand and rifle. At 200 ms after shooting, the stress is transferred to both hands, the
hip and right knee.
In the result of the impact transfer path analysis with the kneeling shooting posture, the initial stress
happened on the shoulder at 0.2 ms. At 0.5 ms after shooting, stress occurred on the right humerus,
scapular, neck and both wrists. At 0.9 ms after shooting, stress occurred on the right forearm, thoracic and
left hand. At 1.4 ms after shooting, stress occurred on the right upper body and hip. At 200 ms after
shooting, the stress is transferred to the left hand, lumber and both feet.
For the prone shooting posture, the initial stress happened on the shoulder and right wrist at 0.2 ms. At 0.5
ms after shooting, the stress occurred on the shoulder, scapular and thoracic. At 0.9 ms after shooting,
stress on the right arm left hand occurred. At 1.4 ms after shooting, stress on the entire thoracic and left
forearm occurred. At 200 ms after shooting, the stress is transferred to the right humerus, left forearm,
entire thoracic and lumber.
Conclusions
The major conclusions from this study are as follows:
1) The finite element model with three shooting postures is developed
2) The stress occurring in the human body by shooting is smaller than 10 MPa
3) The stress from shooting from the prone shooting posture is larger than the stress when shooting from
the other two shooting postures
4) The displacement with the standing shooting posture is the largest
5) The displacement result for the finite element analysis is similar to the result for the dynamic analysis
Reference
1) Meyer F., Willinger R. and Legall F., 2004, “The Importance of Modal Validation for Biomechanical
Models, Demonstrated by Application to the Cervical Spine,” Finite Elements in Analysis and Design,
Vol.40, pp.1835~1855
2) Alan L., Kirth S., Mark C. and Andrew G., 2004, “Finite Element Modeling of the Impact Loading on
Tissue Simulations,” ABAQUS User’s Conference, pp.409~420
3) Toshiyuki M., Wataru U. and Yukio N., 2001, “Simplified Human Body Model for Evaluating
Thermal Radiant Environment in a Radiant Cooled Space,” Building and Environment, Vol.36,
pp.801~808
4) Kim H.J., Yang H.S., Park Y.P, Ryu B.J. and Choi. E.J., 2002, “Analysis of Optimal Isolation System
Considering Human Behavior,” Proceedings of the KSME 2001 Spring Annual Meeting A,
pp.758~763
5) Lee Y.S., Choi Y.J., Han K.H., Chae J.W., Choi E.J. and Kim I.W., 2005, “A Study on the Human
Impulse Characteristics with Standing Shooting Posture,” Key Engineering Materials, Vol. 297-300,
pp. 2314-2319
6) Lee J.W., Lee Y.S., Choi Y.J., Chae J.W. and Choi E.J., 2005, “A Study on Impact Analysis of the
Korean Anthropometric Characteristic on Shooting,” Proceeding of the KSNVE Annual Spring
Conference, pp.150~153