Load sharing and accumulated bond fracture in ion-irradiated carbon mat for energy dissipation.

Multiwalled carbon nanotube (MWNT) aerogel mats were irradiated with carbon ions to explore the effect of irradiation-induced sp bonds and sp bond defects on ultrahigh strain rate mechanical properties. Energy dissipation was measured using a microprojectile impact test. Specific penetration energy [Formula: see text] increased strongly with irradiation with a maximum [Formula: see text] of ~26 megajoules per kilogram, over 200% higher than the previous best energy-absorbing material of pristine MWNT mats and at least an order of magnitude higher than any other material tested at the microscale.

Effect of Nanostructure and Crosslinks on Impact Resistance of Carbon Nanotube Films Under Micro-Ballistic Impact.

Carbon nanotube (CNT) films show great promise as an advanced bulletproof materials due to their excellent energy dissipation ability under impact loadings. However, it is challenging to determine the optimized architecture structure of CNTs to enhance the impact resistance of CNT films. In this study, the impact behavior of CNT films with various architecture structures were studied by micro-ballistic impact experiments and coarse-grained molecular dynamics (CGMD) simulations.

Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels.

We investigated carbon aerogel samples with super low densities of 0.013 g cm (graphite is 2.5) and conducted compression experiments showing a very low yield stress of 5-8 kPa.

Micron-Thick Interlocked Carbon Nanotube Films with Excellent Impact Resistance via Micro-Ballistic Impact.

The highest specific energy absorption (SEA) of interlocked micron-thickness carbon nanotube (IMCNT) films subjected to micro-ballistic impact is reported in this paper. The SEA of the IMCNT films ranges from 0.8 to 1.

Scaling Law for Impact Resistance of Amorphous Alloys Connecting Atomistic Molecular Dynamics with Macroscale Experiments.

Establishing scaling laws for amorphous alloys is of critical importance for describing their mechanical behavior at different size scales. In this paper, taking NiTa amorphous metallic alloy as a prototype materials system, we derive the scaling law of impact resistance for amorphous alloys. We use laser-induced supersonic micro-ballistic impact experiments to measure for the first time the size-dependent impact response of amorphous alloys.

Carbon nanotube sponges filled sandwich panels with superior high-power continuous wave laser resistance.

Effect of highly-porous and lightweight carbon nanotube sponges on the high-power continuous wave laser ablation resistance of the sandwich panel was investigated experimentally. As a comparison, thermal responses of monolithic plate, carbon nanotube film filled sandwich panel, unfilled sandwich panel and carbon nanotube sponge filled sandwich panel subjected to continuous wave laser irradiation were analyzed. Experimental results showed that the laser resistance of the carbon nanotube filled sandwich panel is obviously higher than the unfilled structure.

Dynamic Mechanical Properties of Several High-Performance Single Fibers.

High-performance fiber-reinforced composites (FRCs) are widely used in bulletproof structures, in which the mechanical properties of the single fibers play a crucial role in ballistic resistance. In this paper, the quasi-static and dynamic mechanical properties of three commonly used fibers, single aramid III, polyimide (PI), and poly-p-phenylenebenzobisoxazole (PBO) fibers are measured by a small-scale tensile testing machine and mini-split Hopkinson tension bar (mini-SHTB), respectively. The results show that the PBO fiber is superior to the other two fibers in terms of strength and elongation.

Study on performance degradation and damage modes of thin-film photovoltaic cell subjected to particle impact.

It has been a key issue for photovoltaic (PV) cells to survive under mechanical impacts by tiny dust. In this paper, the performance degradation and the damage behavior of PV cells subjected to massive dust impact are investigated using laser-shock driven particle impact experiments and mechanical modeling. The results show that the light-electricity conversion efficiency of the PV cells decreases with increasing the impact velocity and the particles' number density.

Residual stress analysis of thin film photovoltaic cells subjected to massive micro-particle impact.

Residual stresses play a crucial role in both light-electricity conversion performances and the lifespan of photovoltaic (PV) cells. In this paper, the residual stress of triple junction cells ( GaInP/GaInAs/Ge) induced by laser-driven massive micro-particle impact is analyzed with a novel method based on backscattering Raman spectroscopy. The impact process, which induces damage to the PV cells and brings the residual stress, is also investigated by optical microscopy (OM) and Scanning Electron Microscopy (SEM).