Advances in Materials Science and Engineering
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Arc radius (mm) Figure 10: Maximum stresses and maximum displacements of corrugated board models with different arc radius of flute.
Flute angle ( ∘ ) Figure 12: Maximum stresses and maximum displacements of corrugated board models with different flute angle 𝜃 .
B
𝜙1.10
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Figure 13: The drop test model with different flute height.
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Figure 11: Model of corrugated board with flute angle of 40 ∘ .
3.5. Drop Test 3.5.1. Flute Height 𝐻 . Both primary (consumer) packages and shipping containers have a risk of being dropped or being impacted by other items. Package integrity and product protection are important packaging functions. Drop tests are conducted to measure the resistance of packages and prod- ucts to controlled laboratory shock and impact. Drop testing also determines the effectiveness of package cushioning to isolate fragile products from shock. Effects of flute height 𝐻 on the dynamic mechanical properties of corrugated cardboard model in the drop test based on Cosmos/Works were investigated. A series of models with different flute height 𝐻 were built and shown in Figure 7. The flute heights 𝐻 in models are 2, 3, 4, and 5 mm. The drop test model was shown in Figure 13. A simplified model of corrugated board and goods on the upper board were investigated. Drop height is 0.3 m, initial velocity is 0 m/s, acceleration of gravity is 9.81 m/s 2 , and impact time is 600 𝜇 s. The material of the object on the upper board is Acry- lonitrile Butadiene Styrene (ABS) and the mass is 1.224 × 10 −4 kg. Then the stress and displacement contours of models of corrugated board were obtained and shown in Figure 14 (model with flute height 𝐻 of 5 mm). In order to investigate the stress of goods on the upper board in the drop test, we selected 2 points (A and B point as shown in Figure 13) from the model as the object of study. Then the time-dependent
3.4. Flute Angle 𝜃 . Effects of flute angle 𝜃 on the mechanical properties of corrugated cardboard model were investigated in this section. A series of models with different flute angle 𝜃 were built and shown in Figure 11. The flute angles 𝜃 in models are 40, 50, 60, 70, 80, 90, 100, 110, and 120 ∘ . Fixing the bottom of models and then a static pressure test were made with a pressure of 150 Pa on the top floor. Then the maxi- mum displacement and maximum stress of the models with different flute angle 𝜃 were obtained and the results are shown in Figure 12. From Figure 12, we can see that, with the increase of the flute angle 𝜃 , the maximum stress and maximum displace- ment in the models increase nonlinearly. The maximum stress and maximum displacement change slowly when 𝜃 is less than60 ∘ and then increase sharply when 𝜃 is larger than 60 ∘ . In addition, the number of flute per unit length increases as the 𝜃 decreases, and it means that the corrugated board needs more materials. Therefore, the optimal flute angle 𝜃 couldbe 60 ∘ for corrugated board. According to the Chinese national standards “Corrugated board and standard test method” (GB6544 ∼ 6548-86), the UV-shaped flute corrugated board should be 60 ∘ in the manufacture process. The simulation result is consistent with the standards of corrugated board.
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