Analysis of selected mechanical parameters for foamed materials with non-Newtonian liquid characteristics in terms of their use in aspects of protective helmets

Figures & data

Table 1. Test sample density.

Sample marking	Density (kg/m^3)
P1	235 ± 1
P2	317 ± 1
P3	336 ± 1

Figure 1. Structure of non-Newtonian foamed materials: (a–c) sample P1, (d–f) sample P2 and (g–i) sample P3 real view, computer analysis image and pore distribution in the sample structure, respectively. Note: The full colour version of this figure is available online.

Table 2. Summary of quantitative computer image analysis of the structure of the tested materials.

Sample number	Count (px)	Total area of pores (px^2)	Average area of pores (px^2)	Ratio of pore area to total surface area (%)
P1	249	76,934	308.972	46.441
P2	265	68,788	259.577	41.524
P3	318	34,076	107.157	20.570

Figure 2. The impact test measuring stand (CIOP-PIB, Poland): 1 = vertical frame, 2 = ram beam, 3 = base of 350 kg weight, 4 = sample deflection sensor, 5 = ram, 6 = anvil with a force sensor.

Table 3. Energy suppressed in the sample (E_s) values for P1, P2 and P3 sample types at temperatures T₁ = –30 °C, T₂ = –20 °C, T₃ = –10 °C, T₄ = 20 °C and T₅ = 50 °C.

	Es (J)
Sample marking	T1	T2	T3	T4	T5	Temperature-related differences in suppressed energy T1 and T5, ΔEs (J)
P1	2.17 ± 0.19	2.19 ± 0.16	2.27 ± 0.29	1.76 ± 0.08	1.38 ± 0.06	0.79 ± 0.29
P2	2.11 ± 0.15	2.05 ± 0.11	1.93 ± 0.09	1.76 ± 0.06	1.45 ± 0.03	0.66 ± 0.15
P3	2.20 ± 0.11	2.21 ± 0.14	2.13 ± 0.08	1.94 ± 0.07	1.50 ± 0.05	0.71 ± 0.14

Figure 3. Energy suppressed in the sample (E_s) according to temperature (T₁ = –30 °C, T₂ = –20 °C, T₃ = –10 °C, T₄ = 20 °C and T₅ = 50 °C) for samples P1, P2 and P3 (with linear fitting).

Figure 4. Energy suppressed in the sample (E_s) according to temperature (T) for samples (a) P1, (b) P2 and (c) P3 (with linear fitting and SD).

Figure 5. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for sample P1 at temperatures T₁ = –30 °C, T₂ = –20 °C, T₃ = –10 °C, T₄ = 20 °C and T₅ = 50 °C.

Figure 6. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for sample P2 at temperatures T₁ = –30 °C, T₂ = –20 °C, T₃ = –10 °C, T₄ = 20 °C and T₅ = 50 °C.

Figure 7. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for sample P3 at temperatures T₁ = –30 °C, T₂ = –20 °C, T₃ = –10 °C, T₄ = 20 °C and T₅ = 50 °C.

Figure 8. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for samples P1, P2 and P3 at temperature T₁ = –30 °C.

Figure 9. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for samples P1, P2 and P3 at temperature T₂ = –20 °C.

Figure 10. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for samples P1, P2 and P3 at temperature T₃ = –10 °C.

Figure 11. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for samples P1, P2 and P3 at temperature T₄ = 20 °C.

Figure 12. Pressure force acting on the anvil during the impact (F) as a function of sample deflection (d) for samples P1, P2 and P3 at temperature T₅ = 50 °C.