Back impact (Viano 2001)¶

Model validation information

Added to VIVA+ Validation Catalog on : 2022-06-28 by Jobin John

Version	Date	Performed by	LS-Dyna
0.3.2	2022-06-28	Jobin John	9.3.1
1.1.1	2024-05-21	Jobin John	12.2.1

Available openly under under Creative Commons Attribution 4.0 International License

Summary:¶

The simulated outputs are compared to thecorridors taken from the references of PMHS tests reported by Viano et al., 2001.

Viano, D. C., Hardy, W. N., & King, A. I. (2001). Response of the Head, Neck and Torso to Pendulum Impacts on the Back. Journal of Crash Prevention and Injury Control, 2(4), 289-306. https://doi.org/10.1080/10286580108902573

Published in:¶

John, J., Klug, C., Kranjec, M., Svenning, E., Iraeus, J. (2022). "Hello, world! VIVA+: A human body model lineup to evaluate sex-differences in crash protection." Frontiers in bioengineering and biotechnology 10, https://doi.org/10.3389/fbioe.2022.918904

Experiments by Viano et al. (2001)¶

Information on the subjects/specimens¶

The experiments were carried out on 8 PMHS. The subjects had the age of 62 ± 12 years, body mass of 69 ± 17 kg and height of 173 ± 6 cm.

The test were conducted with a power-assisted pendulum with the weight of 23.4 kg. The cadavers were suspended upright with hands and arms forward. The top of the impactor face was aligned with T1 or T6 for the rear thoracic impacts. The pendulum interface was a smooth, flat circular disc with the diameter of 152 mm and rounded edges. The low-severity impacts were conducted at T1 and T6 followed by a high speed impact at T1. Low speed tests were nominally at 4.4m/s and the high-speed at 6.6 m/s.

Simulations¶

Loading and Boundary Conditions¶

6 loading configurations of hub impacts to the back were used. Both female and male models were impacted using a rigid hub with the diameter of 152 mm and weighing 23 kg. The impact velocities were 4.4m/s for low speed simulations and 6.6 m/s for high speed simulations. The impact locations were at the T1 and T6 vertebrae.

Configuration	Location	Impact v [m/s]	Model

1|T6|4.4|50F| 2|T6|4.4|50M| 3|T1|4.4|50F| 4|T1|4.4|50M| 5|T1|6.6|50F| 6|T1|6.6|50M|

Positioning¶

For the validation purposes we used seated VIVA+ 50F and 50M models rotated for 23° around Y axis to get the torso somewhat vertical. The top of the impactor was aligned with the T1 or T6 for each model, depending on the loading condition.

In [13]:

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simData_50F = pd.read_csv(os.path.join(result_output_dir_50F, dynasaur_output_file_name), 
                          delimiter=';', 
                          na_values='-',  
                          #header = [0,1,2]
                          )
simData_50F
simData_50F = pd.read_csv(os.path.join(result_output_dir_50F, dynasaur_output_file_name), 
                          delimiter=';', 
                          na_values='-',  
                          #header = [0,1,2]
                          )
simData_50F

Out[13]:

	MODEL	MODEL.1	MODEL.2	MODEL.3	MODEL.4	MODEL.5	MODEL.6	MODEL.7	MODEL.8	MODEL.9	...	Bone.46	Bone.47	Bone.48	Bone.49	Bone.50	Bone.51	Bone.52	Bone.53	Bone.54	Bone.55
0	Added_Mass	Added_Mass	Total_Energy	Total_Energy	Internal_Energy	Internal_Energy	Kinetic_Energy	Kinetic_Energy	Hourglass_Energy	Hourglass_Energy	...	T1_COG_az	T1_COG_az	T1_COG_ares	T1_COG_ares	TX_Sternum_Mid_x	TX_Sternum_Mid_x	TX_Sternum_Mid_y	TX_Sternum_Mid_y	TX_Sternum_Mid_z	TX_Sternum_Mid_z
1	time	mass	time	energy	time	energy	time	energy	time	energy	...	time	acceleration	time	NaN	time	displacement	time	displacement	time	displacement
2	millisecond	kilogram	millisecond	kilogram * millimeter 2 / millisecond 2	millisecond	kilogram * millimeter 2 / millisecond 2	millisecond	kilogram * millimeter 2 / millisecond 2	millisecond	kilogram * millimeter 2 / millisecond 2	...	millisecond	millimeter / millisecond ** 2	millisecond	millimeter / millisecond ** 2	millisecond	millimeter	millisecond	millimeter	millisecond	millimeter
3	0.0	0.1294553428888321	0.0	NaN	0.0	NaN	0.0	222.8078155517578	0.0	0.0	...	0.0	0.0	0.0	0.0	0.0	63.52961730957031	0.0	0.0	0.0	356.52252197265625
4	1.0	0.1295063351682317	1.0	NaN	1.0	NaN	1.0	223.13955412103707	1.0	0.17981378894108244	...	0.1	0.0001513632328436225	0.1	0.0011445451941492293	0.1	63.52961730957031	0.1	-4.450748426487436e-09	0.1	356.52252197265625
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
998	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	...	99.5	-0.9152419428757964	99.5	1.6185873720832777	99.5	267.0218202224103	99.5	0.1834452536488317	99.5	304.0452808813994
999	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	...	99.60000000000001	1.3965221166571158	99.60000000000001	1.4146553792905165	99.60000000000001	267.2014806025521	99.60000000000001	0.18641477878732626	99.60000000000001	303.9534224666296
1000	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	...	99.7	0.6808542938287955	99.7	1.0488818207413066	99.7	267.38109528500155	99.7	0.18921529439903828	99.7	303.8614999469399
1001	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	...	99.80000000000001	-1.6710798995696632	99.80000000000001	1.7350783983090114	99.80000000000001	267.56032926154995	99.80000000000001	0.19050510397070974	99.80000000000001	303.7693271793483
1002	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	NaN	...	99.9	0.5968510105950293	99.9	1.1543915087974765	99.9	267.73957386874656	99.9	0.1914508043586769	99.9	303.6762470908435

1003 rows × 68 columns

Model Energies¶

No description has been provided for this image

Head Kinematics¶

Head Rotation¶

Head-Torso Rotation¶

Out[39]:

(-20.0, 100.0)

Head-Torso X-Displacement¶

Head-Torso Z-Displacement¶

Out[25]:

<matplotlib.legend.Legend at 0x1ca077e6280>

Chest Force and Deflection¶

Chest Force vs Deflection¶

In [31]:

hide-cell

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chest_deflection_50F_2 =  simData_50F_2.Bone.T8_COG_x.displacement - simData_50F_2.Bone.Sternum_PX_x.displacement
chest_deflection_50M_2 =  simData_50M_2.Bone.T8_COG_x.displacement - simData_50M_2.Bone.Sternum_PX_x.displacement

chest_deflection_50F_3 =  simData_50F_3.Bone.T8_COG_x.displacement - simData_50F_3.Bone.Sternum_PX_x.displacement
chest_deflection_50M_3 =  simData_50M_3.Bone.T8_COG_x.displacement - simData_50M_3.Bone.Sternum_PX_x.displacement

chest_deflection_50F =  simData_50F.Bone.T8_COG_x.displacement - simData_50F.Bone.Sternum_PX_x.displacement
chest_deflection_50M =  simData_50M.Bone.T8_COG_x.displacement - simData_50M.Bone.Sternum_PX_x.displacement
chest_deflection_50F_2 =  simData_50F_2.Bone.T8_COG_x.displacement - simData_50F_2.Bone.Sternum_PX_x.displacement
chest_deflection_50M_2 =  simData_50M_2.Bone.T8_COG_x.displacement - simData_50M_2.Bone.Sternum_PX_x.displacement

chest_deflection_50F_3 =  simData_50F_3.Bone.T8_COG_x.displacement - simData_50F_3.Bone.Sternum_PX_x.displacement
chest_deflection_50M_3 =  simData_50M_3.Bone.T8_COG_x.displacement - simData_50M_3.Bone.Sternum_PX_x.displacement

chest_deflection_50F =  simData_50F.Bone.T8_COG_x.displacement - simData_50F.Bone.Sternum_PX_x.displacement
chest_deflection_50M =  simData_50M.Bone.T8_COG_x.displacement - simData_50M.Bone.Sternum_PX_x.displacement

Impact force vs time¶

Out[34]:

<matplotlib.legend.Legend at 0x1ca0815cca0>

Deflection vs time¶

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