This paper studies a hyperbolic tangent oscillator arising in a nonlinear packaging system. The high-order nonlinearity makes it difficult to study the system analytically. A modified homotopy perturbation method is proposed, where the initial guess is an approximate solution of the well-known Duffing oscillator; the solution accuracy can be improved by either improvement of the initial guess or continuous iteration. This paper gives a general approach to high-order nonlinear oscillators.

So far shock and vibration are the inherent properties of all packing systems, and various mitigation measures have been considered using packing materials, which result in a large packing size. Now the thing changes, this paper gives an effective thermodynamic technology that can completely avoid shock and vibration. An aerial delivery system is used as an example to elucidate the novel packing system, which requires zero loading velocity when loaded. A thermodynamic model is established to reveal the main factors affecting the packing system.

The sandwich structure of cushioning packaging has an important influence on the cushioning performance. Mathematical fractal theory is an important graphic expression. Based on Hilbert fractal theory, a new sandwich structure was designed. The generation mechanism and recurrence formula of the Hilbert fractal were expressed by Lin’s language, and the second-order Hilbert sandwich structure was constructed from thermoplastic polyurethane. The constitutive model of the hyperelastic body was established by using the finite element method. With the unit mass energy absorption as the optimization goal, the fractal sandwich structure was optimized, and the best result was obtained when the order was 2.5 and the unit layer thickness was 0.75 mm. The Hilbert sandwich structure was compared with the rice-shaped sandwich structure commonly used in industry, and the Hilbert fractal structure had better energy absorption. This has practical significance for the development and application of new cushioning packaging structures.