Shear thickening fluid (STF) is a dense colloidal suspension of nanoparticles in a carrier fluid in which the viscosity increases dramatically with a rise in shear rate. Due to the excellent energy absorption and energy dissipation of STF, there is a desire to employ STFs in a variety of impact applications. In this study, a comprehensive review on STFs’ applications is presented. First, several common shear thickening mechanisms are discussed in this paper. The applications of different STF impregnated fabric composites and the STF’s contributions on improving the impact, ballistic and stab resistance performance have also been presented. Moreover, recent developments of STF’s applications, including dampers and shock absorbers, are included in this review. In addition, some novel applications (acoustic structure, STF-TENG and electrospun nonwoven mats) based on STF are summarized, to suggest the challenges of future research and propose some more deterministic research directions, e.g., potential trends for applications of STF.

Due to the higher thermal and moisture expansions of epoxy coatings than the rigid substrate, these coatings suffer from high thermal and hygroscopic stresses, leading to coating/substrate interfacial crack growth. Herein, a parametric study was conducted systematically on epoxy coatings incorporated with fillers, in order to understand their effects on coating/substrate interface delamination caused by thermal and hygroscopic stresses. A finite element model (FEM) was developed to determine an indicator J-integral value (J_i), in comparison with a critical J_C value to interpret the obtained interface delamination experimental results. FE simulations showed that interfacial pre-cracks located at coating edges were more serious than those at the centre. Once delamination was triggered by thermal shock or moisture absorption, it propagated rapidly along the coating/substrate interface. However, by adding suitable micro-/nano-fillers to the coating the thermal and hygroscopic stresses give lower J_i values, so that delamination crack growth can be effectively controlled. The simulation results demonstrate that the incorporation of fillers with lower Young’s modulus, lower thermal expansion and moisture absorption coefficients, smaller size for soft fillers, larger size for rigid fillers, and suitable aspect ratios for rod-shape fillers to the coatings, are more effective against interface delamination. Hence, useful guidelines for improving the design of epoxy composite coatings against delamination growth can be obtained for different engineering applications.

In the vehicle design, crashworthiness safety has always been a crucial issue; also, social effects are currently attracting much attention for a sustainable-development and friend environment. This study develops and performs a multi-material design for a vehicle body considering both crashworthiness safety and social effects. Numerical vehicle crash models for full-front impact, side impact, off-front impact and roof crush were established and validated according to relevant vehicle test laws. Crashworthiness and social-effect (i.e. weight, cost, manufacture and recycle) objectives with the analytical factors of the vehicle body were defined. Design materials (including both metals and composite materials) were adopted. Uniform design with non-linear normalisation method was utilised for the analysis of the crashworthiness simulation responses. Technique for order preference by similarity to ideal solution (TOPSIS) with the accident-data analysis-based weight ratios was applied for the material design of the vehicle body under multiple objectives. The results show that, when considering both crashworthiness safety and social effects, the composite materials are advantageous for applying to the energy-absorption components; also, different materials have their unique edges in different sections of a vehicle body. This investigation provides a series of useful data for the multi-material design of the vehicle body in engineering.