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Dynamic response for a series of cylindrical shells filled with water were discussed previously, which indicated that the limit buckling load of the cylindrical shells was greatly improved by the presence of water. To obtain a good protective structure, a double layered liquid-filled hemispherical shell structure is designed. Three kinds of structures (single layered empty hemispherical shell, double layered empty hemispherical shells, and single layered liquid-filled hemispherical shell) are compared with the double layered liquid-filled hemispherical shells. The collapse behavior of four kinds of hemispherical shell structures and their deformation modes under drop hammer impact are presented to investigate the effects of inner water on the response of the liquid-filled hemispherical shells. Test results show that the effects of inner water mainly include "distributing loadings" and "ironing effect". Double layered liquid-filled hemispherical shells have the highest bearing capacity among all four kinds of structures. Three-dimensional numerical simulations of all the tested specimens were carried out using ANSYS and LS-DYNA. Under same impact condition, the effective protection space of empty hemispherical shells is very small due to its larger vertex displacement. In terms of generalized specific energy absorption (η) of structures with same vertex displacement, liquid-filled hemispherical shells are better than empty shells. For liquid-filled shells, η of double layered shells is smaller than single layered shell, but single layered shell has no inner space. Parameter analysis indicates that only the outer thickness has a significant effect on the impact force. Increasing the outer thickness and ensuring a reasonable distance between the inner and outer shell can improve the crashworthiness of double layered liquid-filled shells and protect the internal objects.

This paper carried out burst tests on the carbon and polyvinyl alcohol (PVA) fiber high-strength concrete specimens to investigate the effects of fiber type, fiber content, water content, heating rate and test specimen size on the burst, and the whole burst process of fiber-high concrete was photographed and recorded. The results indicated that fiber addition will improve the high temperature burst behavior of the high-strength concrete, and the performance of PVA is greatly different from that of carbon fiber. The water content and heating rate have little influence on the burst of the PVA test specimen, but they will greatly affect the carbon fiber test specimen. The size of the test specimen has a great influence on the burst. For the PVA concrete test specimen, the large size test specimen bursts on the surface, as for the carbon fiber test specimen, the large size test specimen delays the initial burst time, but the burst becomes fiercer.

The compressive strength of two kinds of lightweight concrete was studied. The results show that the incorporation of EPS can improve the plastic deformation ability of concrete. The effect of EPS on the compressive strength of concrete depends on the amount and particle size of EPS foam. The incorporation of manufactured sand can improve the compressive strength of EPS concrete. The effect of the amount of manufactured sand on the compressive strength of EPS concrete depends on the amount of EPS in concrete.

The thermal property of closed-cell aluminum foam is studied numerically and the effects of the distribution of the circular pore on the thermal property are studied theoretically. When the convection and radiation are ignored, the effects of porosity, cell size, and distribution forms of pore on the apparent thermal conductivity are investigated. Moreover, the effects of air in the pore on the thermal property are analyzed as well. Simulation results show that apparent thermal conductivity linearly increases with the increase of porosity, while the cell size and the distribution have negligible effects on the thermal property. By comparison, thermal conductivity of air has slight effect on thermal property of foamed aluminum in the context of small size pore.

Sandwich cellular structure, associated with more excellent mechanical properties and physical characteristic, such as, panel ductility and high core compressibility, is widely used in aerospace, transportation, military equipment and civil infrastructure. Due to the special compression properties of functional graded cores, the graded sandwich structure presented more excellent impact resistance than the ungraded sandwich. This article presents the results of experimental, numerical investigation into the failure mode and dynamic plastic response of layered graded sandwich plate with layered honeycomb cores to air blast loading. The core arrangements (different core density) effects on the structure’s deformation behavior, energy absorption and impact resistance were mainly discussed. Three typical failure modes can be observed, that was, local deformation, global bending and penetration failure. Under specific loading conditions, the graded sandwich had more excellent impact resistant and energy absorption ratio, especially for the density-decreased core arrangement sandwich.

Compressive buckling of laminate plates with a delamination are simulated using ABAQUS 6.8 software. Effects of sizes, positions, asymmetric and shapes of delamination on the compressive buckling are investigated without the consideration of delamination growth and contact. The results indicate the sizes, positions, asymmetric and shapes of delamination have an important influence on compressive buckling.

To solve the problem that nano-hydroxyapatite (nHA) crystals aggregation and non-uniformly distribution in nano-hydroxyapatite/chitosan (CS) composite microspheres, nHA/CS microspheres were prepared through in situ biomimetic method in water-in-oil (W/O) emulsions. The physical and chemical properties of the composite microspheres were investigated by scanning electronic microscopy (SEM), X-ray energy-dispersive spectroscope (EDS), X-ray diffraction (XRD), fourier transform infrared spectroscope (FTIR) and laser particle size analyzer. The results indicate that the composite microspheres are spherical with average size of 8.62 μm and disperse uniformly. Moreover, the nHA crystals are dispersed uniformly within composite microspheres and bonded with CS matrix. The composite microspheres have great potential in bone tissue engineering and drug delivery system.