Data on the impact of an object with different thicknesses of different soft materials at different impact velocities on a dummy head

The purpose of this data is to investigate the effect of different thicknesses of different soft materials samples added to an object on the resultant head acceleration of a developed dummy head upon impact. The object was a cylinder (10 × 10 cm2, diameter and height) and weighs 0.4 kg. The investigated materials were Ecoflex, Dragon Skin, and Clay while the thickness were 1 mm, 2 mm, 3 mm, and 5 mm. The velocities of the impacts for the 108 experiments were between 1 m/s and 3 m/s. Three severity indices (i.e. peak head linear acceleration, 3 ms criterion and the Head Injury Criterion (HIC)) were calculated from the raw acceleration data. The impact velocities were tabulated from the video recordings. A summary of the processed data and the raw data are included in this dataset. Online repository contains the files: https://doi.org/10.7910/DVN/TXOPUH.


Data
The Harvard Dataverse link contains a readme file, raw data files, and a summary file [1]. The readme file provides a detailed description about the raw data files and the summary file. The raw data files composed of the National Instruments (NI) TDMS files that contain the raw acceleration readings reported in the gravitational acceleration (g ¼ 9.81 m/s 2 ). The summary file contains the processed raw acceleration readings categorized according to the materials investigated and their thicknesses. Furthermore, it contains the analysis for the three severity indices.
The file LabView_raw_acceleration_data.rar in the online repository contains the raw acceleration readings of the embedded sensor (i.e. accelerometer). This file contains three subfolders, namely clay, dragon skin, and ecoflex. Each material folder is further subdivided to four subfolders based the thicknesses considered, which were 1 mm, 2 mm, 3 mm, and 5 mm. Finally, each folder contains 9 TDMS 1 files representing 9 different experiments.
The columns inside the TDMS files and their corresponding descriptions are summarized in Table 1.
The file processed_summary.xlsx contains a summary of the processed data categorized by tabs based on the material tested (i.e. ecoflex, dragon skin, and clay). Each tab contains the thicknesses considered (i.e. 1 mm, 2 mm, 3 mm, and 5 mm) and the corresponding analysis for the peak head linear Specifications Value of the Data The data could be used generally for safety purposes to understand head's acceleration due to impacts. The data could be used to investigate the potential of soft materials in reducing any harm to the head. Optimizing toys' designs to improve their safety. acceleration (g), the 3 ms criterion (g), and the Head Injury Criterion (HIC). Additionally, it contains the analysis for the impact velocity (m/s 2 ) for each experiment.

Experimental setup
The experimental setup was based on a low-cost developed dummy head. The dummy head was 3D-printed that was made of polylactide (PLA). Clay was added to make the dummy head reach a mass of 3.1 kg, which is very close to that of children's dummy heads. The accelerations of the head were measured with a tri-axial accelerometer embedded inside the head. This head model was placed in a dedicated frame with ropes (Fig. 1). The readings of the sensor were read at 20 kHz through a data acquisition card. Our earlier studies provided more detailed overview of the experimental setup [2,3].

Impactor preparation
The impactor used was cylindrical in shape (10 Â 10 cm 2 ) and weighs 0.4 kg (Fig. 2). Dimensions selected are within the expected dimensions of that of small robots or toys [4e6]. The impactor was built using a 3D printer. Samples (5 Â 8 cm 2 ) of the soft materials (i.e. Clay, Ecoflex OO-30, and Dragon skin FX Pro) were attached to the area of impact (Fig. 2).

Procedures
A total of 108 impact experiments were conducted covering all the three soft materials and the four thicknesses. Tying the object to the frame allowed the generation of different impact velocities by changing the height at which the object is dropped. This approach achieved consistency in terms of the impact velocities levels across all experiments. All impacts were recorded in slow-motion (240 fps, 720 pixels) and an open-source video software (Tracker version 4.10.0) was used in the analysis for impact velocities. A LabView script was used in acquiring and storing the raw data while a MATLAB script was used to post-process it for the three severity indices.